High precision X-ray measurements 2021

8 Jun 2021, 09:00 → 10 Jun 2021, 17:30 Europe/Rome

Alessandro Scordo (LNF)

Overview

High Precision X-ray Measurements 2021 conference is the second edition of the HPXM2018 workshop, held at the INFN Laboratories of Frascati in 2018.

In the wake of the success of the 2018 edition, HPXM2021 is planned with the twofold aim to consolidate the existing interconnections between the research teams and foster creating new ones, offering the opportunity for all the participants to discuss and share the results of their activities focusing on a common protagonist: X-ray precision detection.

The aim of this workshop is to inform the participants on the most recent developments in X-ray detection technologies and their possible impacts in various sectors like nuclear physics, astrophysics, quantum physics, XRF, XES, EXAFS, PIXE, plasma emission spectroscopy, monochromators, synchrotron radiation, radioprotection, telescopes and space engineering, medical applications, food and beverage quality control and elemental mapping.

Ray tracing simulations, graphite mosaic crystals and their applications will have a special focus.

The scientific program consists of invited lectures from distinguished scientists and oral presentations given by the participants; a technical and industrial session is also foreseen.

Best Young Researchers presentation award:

A best presentation contest will take place to honor the most inspiring talks presented by Ph.D students during the conference. Winners, elected by a commission to be selected among the conference participants, will be awarded prizes provided by the MDPI sponsor.

Main Topics:

X-ray energy detectors
X-ray position detectors
Spectrometers
X-ray tracing simulations
X-ray optics
Graphite based applications
X-ray imaging
Chemical analysis
X-rays in biological applications
X-rays in astrophysics
Medical applications
X-rays in nuclear physics
X-ray transitions of exotic atoms
Agrifood applications

Venue:

The conference, originally intended to take place in the INFN Laboratories of Frascati, WILL BE HELD ONLINE.

 

 

 

Workshop Chair:

A. Scordo, Laboratori Nazionali di Frascati, INFN, Italy


Scientific Committee:

A. Balerna, Laboratori Nazionali di Frascati, INFN, Italy
D. Bleiner, Swiss Federal Institute of Materials Science & Technology (Empa), Switzerland
C. Curceanu, Laboratori Nazionali di Frascati, INFN, Italy
S. Dabagov, Laboratori Nazionali di Frascati, INFN, Italy
C. Fiorini, Politecnico di Milano and INFN, Italy
T. Hashimoto, Japan Atomic Energy Agency (JAEA), Japan
M. Lerch, Center for Medical Radiation Physics, University of Wollongong, Australia
A. Marcelli, Laboratori Nazionali di Frascati, INFN, Italy
R. Bedogni, Laboratori Nazionali di Frascati, INFN, Italy
J. Zmeskal, Stefan Meyer Institute (SMI), Vienna, Austria


Local Organizing Committee:

M. Miliucci, F. Napolitano
A. Tamborrino Orsini (secretariat)


The workshop is sponsored by MDPI Publishing

The works presented during the workshop will be published as regular articles without charges in a Special Issue of  Condensed Matter, an international open access journal on the physics of condensed matter published quarterly online by MDPI and recently indexed in Scopus.


 

Tuesday, 8 June

Session: Morning #1

Convener: Alessandro Scordo (LNF)

1 Introduction from the LNF Director and Organizer

Speakers: Fabio Bossi (LNF), Alessandro Scordo (LNF)

HPXM2021.pdf

2 Opening Lecture: Wilhelm Conrad Röntgen –Discovery and first attempts to clarify the physical nature of X-rays

Wilhelm Conrad Roentgen – born in Remscheid, Germany world renowned researcher, brilliant physicist and receiver of the first Nobel Prize. His work revolutionized medical diagnostics and paved the way for numerous applications in modern science and technology without which our modern world would be inconceivable. An extraordinary personal and historic achievement – and yet Roentgens life and work represent much more: a timeless universal message for creative thinking, the positive driving force behind all cultural and social developments as well as behind technological progress and innovation. Roentgen found the start of his career in August Kundt’s physics laboratory in 1870. On November 8, 1895 he discovered a new kind of invisible matter penetrating rays. He called them x-rays. At a single stroke Roentgen was in the spotlight of publicity. His rays were both of scientific and public interest. The physical fundamentals and the biological effects of the new rays were largely unknown at the end of the 19th century. At the beginning, everyone who used x-rays in any way was an experimenter. Differing scientific cultures – medicine, physics and engineering – came together at this new interface. The time after Röntgen’s discovery was characterized by a public feeling of elation about the new kind of rays and their possibilities. On the other hand, in the early 20th century a whole generation of most gifted and excellent scientists was affected by Roentgen’s revolutionary discovery. Amongst them we can find great names and Nobel laureates like: Sir George Stokes, Charles Glover Barkla, Arnold Sommerfeld, Max von Laue, Henry G.J. Moseley, Arthur Holly Compton, and last but not least: Sir William Henry Bragg and Sir William Lawrence Bragg. The great scientific work of the Bragg family led to the answers surrounding the fundamental questions about the structure of the matter embedding the exploration of the human genome.
The lecture gives an insight into the life of the first Nobel Prize winner in physics and discusses the efforts in physics to find out the physical nature of the new rays.

Speaker: Uwe Busch (Deutsches Roentgen Museum of the City of Remscheid)

10:20 Coffee break

Session: Morning #2

Convener: Gaetano Campi (Istituto di Cristallogefia - CNR)

3 XAS (X-Ray Absorption Spectroscopy) spectroscopy: state of the art and some applications in material science

X-Ray Absorption spectroscopy (XAS) is a powerful tool to investigate both the electronic and geometrical structure around to a well defined absorbing atom belonging to any type of material, from biological samples to condensed matter. In this talk I will present a general theoretical scheme to analyze the experimental data from the edge up to very high energy. This scheme, based on the Multiple Scattering theory, allows a complete recovery of the experimental data, and, in particular, I will discuss a new method to get structural quantitative information using the low energy part of the spectrum, starting from the edge. This procedure, that has been recently proposed in the literature, allows a complete three dimensional determination of the local geometry around the photo-absorber in many different systems. Some chemical and biological applications will be also presented in details.

Speaker: Maurizio Benfatto (LNF)

4 Precision X-ray spectroscopy of muonic atoms to explore QED under strong electric fields

Precision X-ray spectroscopy of the muonic atoms isolated in vacuum is an ideal probe to explore quantum electromagnetic dynamics (QED) under extremely strong electric fields, which is one of the major topic in fundamental atomic physics. We have performed the measurement using an X-ray spectrometer based on multi-pixel array of superconducting transition-edge-sensor (TES) microcalorimeters at J-PARC MLF muon facility (Tokai, Japan).

Negatively-charged muon can be bound by the Coulomb field of an atomic nucleus, so-called muonic atom. In this system, the internal electric field strength between muon and nucleus is proportional to the square of the mass ratio of electron and muon. Muon is about 200 times more massive than electron, so it is 40,000 times stronger than ordinary atoms. Furthermore, since the internal electric field strength is proportional to the cube of the atomic number Z, it is possible to realize an ultra-strong electric field by using heavy muon atoms.

In QED, the electric field strength Ec = 1.32 × 10^18 [V/m] called Schwinger limit is a scale above which the electromagnetic field is expected to become nonlinear. However, it has never verified QED in a strong electric field above Ec, and it is unknown what kind of physics will appear there. The purpose of this study is to accurately determine the transition energy of muonic atoms and compare it with the latest QED calculation to verify the QED under extremely high electric field conditions exceeding Ec [1].

In order to perform such high-precision muonic-atom X-ray spectroscopy, it is important to prepare muonic atoms in which no bound electrons are present. This is because if the bound electrons remain, the shielding effect of the electrons shifts the energy level of the muonic atom, which hinders the highly accurate determination of the QED effect.
The muonic atom generated in the highly excited state is stripped of bound electrons during the deexcitation process, and conveniently becomes a highly-charged muon-atom ion composed only of an atomic nucleus and a muon. However, if a high-density target is used, electrons will be refilled from surrounding atoms during deexcitation. Therefore, it is essential to use a low-density gas target (~ 0.1 atm). However it is experimentally difficult to efficiently stop muons in such a low-density target due to the large momentum distribution of muon beam, resulting in insufficient x-ray yield with the conventional high-resolution x-ray spectroscopy technology.

We have performed the high-resolution muonic atom X-ray spectroscopy with low-density gas target with a combination of the world highest intensity pulsed negative muon beam at J-PARC and an X-ray spectrometer based on a 240 pixel array of TES microcalorimeters in March 2019 [2] and January 2020. In this presentation we will give an overview of this project and report the latest results.

[1] N. Paul et al., Physical Review Letters 126 (2021) 173001.
[2] S. Okada et al., Journal of Low Temperature Physics 200 (2020) 445.

Speaker: Shinji Okada (Chubu University)

5 The EuPRAXIA@SPARC_LAB project and related R&D activities at LNF.

A new Research Infrastructure named “EuPRAXIA@SPARC_LAB” has been recently funded by the Italian Minister of Research and INFN. In its final configuration it will equip LNF with a multi-disciplinary user-facility, based on a soft X-ray Free Electron Laser (FEL) driven by a ~1 GeV compact electron accelerator. This fundamental goal will be achieved by using a high gradient X-band RF linac to excite plasma waves in the plasma accelerator module.

This activity is performed in synergy with the H2020 European Design Study “EuPRAXIA” that has delivered the Conceptual Design Report at the end of 2019 and it is now developing towards the implementation of an international user facility.

In this talk we report about the recent progresses on the going scientific and technical advancement for EuPRAXIA@SPARC_LAB and on the recent experimental results obtained at the LNF test facility SPARC_LAB.

Speaker: Massimo Ferrario (INFN-LNF)

Ferrario_HPXM_021.pdf

11:40 Coffee break

Session: Morning #3

Convener: Anna Bergamaschi (Paul Scherrer Institut)

6 DANAE – A direct search for light Dark Matter with DEPFET-RNDR detectors

In recent years, the direct search for light dark matter (DM) particles at the sub-GeV/c² mass scale gained increasing interest due to several benefits of the theory – concerning the explanation of astrophysical observations – as well as due to the experimental exclusion of heavier candidates. One promising option for a direct detection is the scattering of light DM particles with electrons. Highly sensitive silicon semiconductor devices with deep sub-electron noise provide the opportunity to extend the detection thresholds down to a few MeV/c².
One technology, which is capable to achieve the required distinction between single signal electrons are Depleted P-channel Field Effect Transistor (DePFET) with Repetitive Non-Destructive Readout (RNDR). Initially, DEPFET detectors were developed for X-ray spectroscopy and were modified to enable a variety of different applications. The low noise performance of RDNR-DeFPETs below 0.2 e-ENC at readout times in the range of ms/pixel has already been demonstrated with single pixel devices [1]. We will present preliminary results from a 64x64 pixel matrix of RNDR-DePFETs. The DANAE project aims to apply DePFET-RNDR matrices for the direct DM searches and detailed instrumental studies are necessary before the background can be investigated and scientific measurements become feasible. In this contribution we will introduce the DANAE project and present the RNDR-DEPFET technique before discussing the status, preliminary results, and prospects of the project.
[1] A. Bähr, H. Kluck, J. Ninkovic, J. Schieck and J. Treis, Eur. Phys. J. C77 (2017) 905, arXiv:1706.08666

Speaker: Wolfgang Treberspurg (Institute of high energy physics, Austrian Academy of Sciences)

7 Dynamical and correlated disorder at nanoscale in complex materials

Dynamical structural and electronic disorder at nano and mesoscale plays an important role in the functionality of complex materials. Here local heterogeneity and weak interactions developing between structural units cause dynamical spatio-temporal configurations with correlated disorder. Visualizing these configurations is fundamental for understanding the physical properties of complex matter and requires advanced methodologies based on high precision X ray measurements. We discuss the connections between the dynamical correlated disorder at nanoscale and the functionality in recent cases studies.

Speaker: Gaetano Campi (Istituto di Cristallogefia - CNR)

Campi_HPXM_2021.pdf

8 Unique properties of Pyrolytic Graphite for extreme conditions

Modern accelerators offer more bright source of X-rays and particles, intense laser beams and reproduce astrophysically relevant conditions in laboratory. To investigate or monitor such sources, materials that survive in the vicinity of extreme processes are needed.
Well Aligned Pyrolytic Graphite (WAPG) offers interesting solutions for working in a harsh environment due to a unique combination of properties. Consisting of light carbon with of highest purity, the material has outstanding thermal conductivity and can withstand extreme thermal and radiation loads, neutrons and debris flow. An important feature of all forms of WAPG is unique reflectivity of X-rays that is additionally increased by enlarged acceptance angle in the case of Graphite Optics (GrO).
WAPG is obtained by stress annealing of pyrolytic carbon at temperatures near 3000oC. Variation of annealing conditions results in different PG forms, whose properties can be configured for different applications.
The flexible forms of PG are used for production of GrO. The optics in von Hamos geometry became a routine tool for analysing the temperature, density and ionization of plasma. The advantage of GrO for plasma application is discussed. Unique thermal and radiation stability makes GrO applicable in an extreme environment, where other optical elements degrade. Some examples of the optics used by our customers in X-rays Thomson Scattering (XRTS)- spectrometer were given.
GrO as well as bulk HOPG crystal are promising as pre-reflector protecting the subsequent detection chain for ITER and similar facilities.
Thin films of a few cm2 and only of 1-5um micron thick are available from a HOPG produced in special annealing conditions. The films are recently used as stripping foils of increased stability for cyclotrons and innert X-way windows in analytical cuvees.

Speaker: Inna Grigorieva (Optigraph GmbH)

Grigorieva_PG for extreme conditions.pdf

13:00 Lunch

Session: Afternoon #1

Convener: Massimo Ferrario (LNF)

9 Silicon Drift Detectors and fast readout electronics for high-rate, high-resolution X-ray measurements

Silicon Drift Detectors (SDDs) are widely used in X-ray measurements, in particular for spectroscopy applications. New challenges in terms of counting rates, for instance with new generations of synchrotron light sources, push the development towards new topologies of monolithic SDDs equipped with fast CMOS readout electronics. In this work, recent approaches taken by our team, namely ARDESIA and SCARLET projects, are illustrated together with example of detectors measurements already carried out at synchrotron facilities.

Speaker: Carlo Ettore Fiorini (MI)

10 Analysis and design of X-ray optical systems applying hierarchical models including partial coherence

In this talk I will present how to design and analyze optical systems using computer tools in Oasys [1] with different complexity. The idea is starting from simple analytical calculations by hand, then applying ray-tracing, based on geometrical optics that is well adapted for systems using incoherent light beams. In the case that the coherent fraction of the beams is close to one, models bases on wave optics propagation in 1D or 2D are used. In case of hard X-ray synchrotron beams from new low-emittance storage rings, the coherent fraction may vary (5-50%) and we apply partial coherence methods based on coherent mode decomposition.

I will illustrate this scheme with a number of examples calculated using Oasys: Ray tracing analysis of a mirror designed to suppress aberrations (the “diaboloid” shape) [2], design an adaptive mirror to correct for wavefront distortions in a fully coherent beamline at the projected ALS-U [3], match two transfocators in a partially coherent hard X-ray beamline at EBS-ESRF. Finally I will discuss some models for monochromators using non-perfect crystals, such as Graphite.

[1] L Rebuffi, M Sanchez del Rio (2017) OASYS (OrAnge SYnchrotron Suite) : an open-source graphical environment for x-ray virtual experiments Proc.SPIE 10388: 10388-10388. http://dx.doi.org/10.1117/12.2274232

[2] V V Yashchuk, I Lacey, M Sanchez del Rio (2020) Analytical expressions of the surface shape of diaboloid mirrors SPIE Proceedings 11493: 128-140. http://dx.doi.org/10.1117/12.2568332

[3] M Sanchez del Rio, A Wojdyla, K A Goldberg, G D Cutler, D Cocco, H A Padmore (2020) Compensation of heat load deformations using adaptive optics for the ALS upgrade : a wave optics study J. Synchrotron Rad. (2020). 27, 1141-1152 https://doi.org/10.1107/S1600577520009522

Speaker: Manuel Sanchez del Rio (ESRF)

frascati_meeting_srio_v2.pdf

11 Advanced spectroscopy and microscopy studies for chemical elements evaluation by micro-X-ray Fluorescence and polycapillary optics

Advances in x-ray techniques, including x-ray optics, have paved the way to obtain challenging results in several research fields thanks to the improvement in terms of spatial resolution. This is particularly true for x-ray fluorescence (XRF), where the combination of conventional x-ray sources with polycapillary optics has permitted to have high flux and high focused beams. However, XRF spectroscopy is mainly dedicated to qualitative studies while quantitative analysis still remains a strong hurdle mainly due to important matrix effects that affect the signal related to the chemical components under evaluation.
At LNF XLab Frascati the expertise, gained on x-ray techniques and on polycapillary lenses, has allowed researchers to carry out advanced μXRF studies1. RXR (Rainbow X-ray), is the experimental station dedicated to 2D/3D XRF micro-imaging and TXRF analysis, being equipped with 2 detectors of different energy efficiency and working in confocal mode with the source coupled with a full-lens and both the detectors combined with dedicated half-lenses, has allowed researchers to carry out advanced X-ray spectroscopy and X-ray microscopy studies2. The potentialities of our RXR facility are showcased by depicting the results obtained in some application scenarios such as: a) chemical composition of tree rings for evaluating the influence of environmental context, b) study of a “fresco” fragment to assess the presence of damages3, c) pigment recognition within antique artifacts by the application of a quantitative method (FPM)4,5.

Speaker: Valeria Guglielmotti (Istituto Nazionale di Fisica Nucleare)

15:00 Coffee break

Session: Afternoon #2

Convener: Manuel Sanchez del Rio (ESRF)

12 Advanced X-ray Studies @ XlabF

X-ray applications are widely used in the world. By the way, due to the high interaction between radiation and matter, experimental setup, in particular optical devices, suitable for X-ray radiation is not trivial [1-3]. Consequently, performing high efficiency experiment is almost possible only in dedicated Laboratories, as Synchrotron Radiation labs.
However, in the last 30 years, the studies concerning novel advanced material have fostered the development of several solutions for more efficient X-ray systems [4], necessary to perform high spectroscopy analysis as well as wimaging techniques applied in Medicine/Pharmacology, Cultural Heritage, Geology and Environment, Electronics, Aerospace, etc…
The main accent will be highlighted to advance tools for X-ray both Imaging and Spectroscopy based on combination of modern polycapillary optics and developed reconstruction software together with commercially available systems [5-7].
Recent results (principally in high resolution X ray Imaging [8], µXRF [9-10] and µCT [11]) obtained at XLab-Frascati will be discussed.

References
[1] K. Tsuji, J. Injuk and R. Van Grieken, "X-Ray Spectrometry: Recent Technological Advances", Cap. 3, Ed. Wley, (2004).
[2] M.A. Kumakhov and F.F. Komarov, Phys. Rep. 1915, 289-350(1990).
[3] S.B. Dabagov, Phys. Usp. 46 10, 1053-1075 (2003).
[4] D. Hampai et al., NIM B 355, 264-267 (2015).
[5] S. Smolek, B. Pemmer, M. Fölser, C. Streli and P. Wobrauschek, Rev. Sci. Instr. 83, 083703 (2012).
[6] K. M. Dabrowski, D. T. Dul, and P. Korecki, Opt. Expr. 21(3), 2920-2927 (2013).
[7] K. Nakano et al., Anal. Chem. 83, 3477-3483 (2011).
[8] F. Bonfigli et al., Opt. Mat. 58, 398-405 (2016).
[9] G. Cappuccio et al., Cond. Matt. 3, 33 (2018).
[10] D. Hampai et al., JINST 13, C04024 (2018).
[11] L. Marchitto et al., IJMF 70, 15-21 (2015).

Speaker: Dariush Hampai (LNF)

13 New multichannel modular detection system based on Silicon Drift Detectors

A detection system specially designed and developed in order to optimize the potentials of XRF-XAFS sensitivity and efficiency is presented. It consists of 8 monolithic multipixel arrays, each with 8 (SDD) cells with a total area of 570 mm$^2$. Optimized to work in an energy range of 3-30 keV, this 64 channels integrated detection system includes ultra-low noise front-end electronics, dedicated acquisition system, digital filtering, temperature control and stabilization. Room temperature characterization tests at ELETTRA Synchrotron Trieste demonstrated very interesting results; they include an energy resolution at the Ka line of Mn 5.9 keV below 170 eV FWHM. The system is now installed and operating at the XRF-XAFS beam line of the SESAME Synchrotron light source in Jordan.

Speaker: Daniela Cirrincione (INFN-Ts)

HPXM2021-CirrincioneD.pdf

14 Laser-Induced XUV Spectroscopy (LIXS) for High-Precision Lithium Analysis of Energy Materials

Laser-induced breakdown spectroscopy (LIBS) is a powerful elemental analysis method thanks to the negligible sample preparation, rapid detection, and a spatially resolved sensitivity down to trace level in any kind of sample matrix [1]. LIBS has also the ability for 2D spatially resolved mapping as well as depth profiling at a given location showing a local 3D mapping [2], such as 3D-mapping of an electrode in a lithium-ion battery. However, conventional LIBS is operated in the UV-visible spectral range (LIBS-OES), where the precision of LIBS is limited by the low stability and repeatability of the plasma emission [3]. This is particularly critical for spatially resolved analysis at nano-scale, where the sample heterogeneity is affected by the measurement precision. Utilization of the plasma emission in the extreme ultraviolet (XUV) wavelength range proved to fully overcome such limitations. Laser-Induced XUV Spectroscopy (LIXS) was applied to quantify lithium in energy materials, where the distribution of this element plays an important role for the functionality, for instance, in battery technology. The LIXS signal (7% RSD) is proved three times more stable than for LIBS-OES (23% RSD) by comparing the spectra of lithium fluoride (LiF) from 20 laser shots in single-shot mode. Moreover, a series of calibration samples Li2O/MnxOy were processed with LIXS to obtain the Li concentration calibration function for the quantitative analysis. By using the obtained calibration function. The 3s-limit of detection of Li was calculated to be 0.12%. Depending on the level of LOD, LIXS can currently only be used for the analysis of non-trace elements in matrices, where the spatial distribution is the key information. There is an urgent need to optimize the instrumentation of LIXS to further improve its spectral intensity and sensitivity.

[1] D. W. Hahn and N. Omenetto, “Laser-Induced Breakdown Spectroscopy (LIBS), Part II: Review of Instrumental and Methodological Approaches to Material Analysis and Applications to Different Fields,” Appl. Spectrosc., vol. 66, 347–419, 2012.
[2] S. Imashuku et al., “Quantitative lithium mapping of lithium-ion battery cathode using laser-induced breakdown spectroscopy,” J. Power Sources, vol. 399, 186–191, 2018.
[3] E. Tognoni and G. Cristoforetti, “Signal and noise in Laser Induced Breakdown Spectroscopy : An introductory review Optics & Laser Technology Signal and noise in Laser Induced Breakdown Spectroscopy : An introductory review,” Opt. Laser Technol., vol. 79, 164–172, 2015.

Speaker: Di Qu (EMPA)

16:15 Coffee break

Session: Afternoon #3

Convener: Peter Predehl (Max-Planck-Institut für extraterrestrische Physik)

15 CdZnTe based detectors for X and gamma ray spectroscopic imaging.

CdZnTe crystals are largely exploited for the production of room temperature operating x and gamma ray spectroscopic imaging detectors operating in the 10 keV-1 MeV. This is because of CdZnTe large x-ray stopping power (large mean atomic number), high room temperature electrical resistivity (large enough band gap), good energy resolution (reasonable carrier transport properties).
In this paper, the last results about the realization and characterization of CdZnTe detectors at IMEM-CNR in collaboration with several groups are presented. The detectors are developed for several applications such as industrial non-destructive testing, spectroscopic imaging at Synchrotron facilities, decommissioning, environmental control, high energy physics and astrophysics.
The presentation will focus on the preparation of the detectors as well as on the improvements in the read out electronics and signal processing.

Speaker: Andrea Zappettini

16 Testing foundations of Quantum Mechanics in the cosmic silence

The VIP experiment aims to perform high sensitivity tests of the Pauli Exclusion Principle (PEP) for electrons, and look for a possible small violation.
In Local Quantum Field Theories approach any PEP violating transition is strongly constrained by the Messiah Greenberg Superselection (MGS) rule, which forbids superpositions of states with different symmetry. Such models can then be only tested with open systems. This condition is realised in VIP-2 by introducing “new” electrons in a pre-existing system of electrons, and then testing the resulting symmetry state. The data analyses results from the newest VIP-2 Open Systems data taking will be presented.
It was recently shown that a large class of Quantum Gravity models embeds the violation of PEP, violating the MSG rule, as a consequence of the space-time non-commutativity. High sensitivity tests of PEP violation in closed systems turn then to be the better candidates to put strong experimental limits on the energy scale of the non-commutativity emergence in Quantum Gravity. The results of exploratory studies based a High Purity Germanium (HPGe) Detecors and high radio-purity Roman Pb targets will be shown.

The extremely low background environment of LNGS is also suitable for investigating one of the main mysteries of Quantum Mechanics Foundations: the measurement problem. Collapse models propose phenomenological solutions to the measurement problem; by modifying the linear and unitary evolution of the Schroedinger equation adding a non-linear term and the interaction with a stochastic noise field. Collapse models account for the wave function collapse in space, which is characterised by an amplification mechanism, the biggest the mass the faster the reduction of the wave packet. The quantum to classical transition is then realised by ensuring that macroscopic objects always have well defined positions. On the other hand the interaction with the noise field is very small at the microscopic level, where the standard Schroedinger evolution dominates. The results of our analyses, setting the strongest constrains on collapse models, will be presented.

Speaker: Kristian Piscicchia (LNF)

17 Precision X-ray spectroscopy of hadronic atoms - pionic hydrogen challenges and results

Precision X-ray spectroscopy of atomic transistions to the ground state of hadronic hydrogen can be used to extract the values of energy shift and broadening of the 1s ground state. Only the ground state is measurably influenced by the strong interaction meson-nucleon. A strongly refined experiment using a crystal spectrometer system was performed at PSI which resulted in improved shift and width values of pionic hydrogen. The data analysis was compicated due to the small shift and width values and especially challenging because of electromagnetic cascade effects. The talk will discuss the experiment, results and implications.

Speaker: Johann Marton (Stefan Meyer Institute)

Wednesday, 9 June

Session: Morning #1

Convener: Francesco D'Acapito (CNR)

18 Digital spectroscopic improvements in CdZnTe detectors for 2-D and 3-D spectroscopic X-ray and gamma ray imaging.

In the last decade, cadmium–zinc–telluride (CdZnTe or CZT) detectors are widely proposed for the development of room-temperature spectroscopic X-ray and gamma ray imagers. Recently, within an Italian research collaboration (DiFC of University of Palermo, IMEM-CNR of Parma and INAF/OAS of Bologna), we developed new imager prototypes, based on CZT pixel/strip detectors and digital pulse processing (DPP) electronics, for X-ray and gamma ray imaging applications (up to 1 MeV). In this framework, we will present the performance of the new detectors and the potentialities of the digital analysis for performance improvements.

Speaker: Leonardo Abbene (University of Palermo, Italy)

19 Channeling X-rays for Coherence Measurements

In this report the possibility for radiation coherence measurements in the x-ray energy range will be reported. Thirty years ago, the theory of x rays channeling in capillary systems has been established at basic principles. Later, it was developed extending for any kind of channel-based optical systems being simultaneously proved by various experimental tests. Measurements on diffraction limits could be considered as the most precise ones at fixed radiation frequencies. The purpose of my report is, after brief review of past research, to demonstrate the sensibility of bound x rays to their coherence characteristics that could be future fine probes for advanced x-ray measurements.

Speaker: Sultan Dabagov (INFN Lab Naz di Frascati)

20 Mastering Synchrotron Microbeams for Radiotherapy: effective cancer treatment with remarkable healthy tissue tolerance

Introduction
Radiotherapy of highly radiation-resistant brain cancers and non-small cell carcinomas in the head, neck and thoracic cavity is limited by the radiation tolerance of the brain and spinal cord. Synchrotron Microbeam Radiation Therapy (MRT) has a remarkably high normal tissue tolerance and allows delivery of extremely high irradiation doses. MRT uses collimated synchrotron radiation to produce quasi-parallel microbeams 25-50 μm wide and separated 100-400 μm apart. This creates high in-beam (peak) doses and low (valley) dose regions between microbeams. Our research at the Australian Synchrotron investigates the efficacy of MRT in treating cancer and its impact on the brain and spinal cord. Furthermore, our study showcases recent advancements in synchrotron cancer treatment technologies including state-of the art dosimetry, in silico Monte Carlo dose modelling, image-guided tumour targeting, individualized MRT irradiation planning, and includes long term preclinical brain cancer survival following MRT.

Methods
Our preclinical studies were performed in Hutch 2B of the Imaging and Medical Beam Line at the Australian Synchrotron. Juvenile Fischer and Wistar rats were used to investigate MRT of the brain and spinal cord, respectively, in two independent studies. The first study treated 9L glioblastoma cancers of the brain 12 days after implantation and investigated long term survival, brain chemistry and clinical signs following irradiation with 400 – 900 Gy microbeams. The second study of the spinal cord determined the acute (up to 3 days post irradiation) and subacute (6 days post irradiation) response of the spinal cord to MRT for microbeam doses up to 800 Gy. Electrophysiology measurements, MR imaging, and motor and sensory function tests were used to determine spinal cord function before and after MRT.

Results
Preclinical irradiation of 9L tumours showed a 570% increase in the mean survival compared to control rats. Long-term survival was linked to adequate dose coverage of the tumour and tumour volume. Histological results showed early tumour response to microbeams 24 hours after MRT, and the reestablishment of functional neurological tissue in long-term survivors (up to 528 days post tumour implantation).
In the spinal cord, no neurologic deficits or loss in motoric abilities was observed up to peak doses of 400 Gy. Reversible neurologic deficits occurred at 450 Gy, and non-reversible neurologic deficits developed with peak doses above 450 Gy.
These results demonstrate a remarkable brain and spinal tissue tolerance towards synchrotron microbeam radiation doses. Our work will assist the design of future MRT studies, showcase MRT as a treatment modality for radiation-resistant brain cancer, and benchmark the tolerance of CNS tissues to MRT.

Speaker: Elette Engels (University of Wollongong)

21 Electronic and structural investigation on gold monometallic and bimetallic nanoparticles using x-ray absorption fine structure spectroscopy.

Monometallic and bimetallic gold nanoparticles (NP) have been largely investigated for their applications in many different fields including catalysis and biomedicine. XAFS or X-ray Absorption Fine Structure spectroscopy can give important information on their electronic and structural properties. A short review of L3-near edge and extended X-ray absorption fine structure information achievable on monometallic and bimetallic Au nanoparticles synthesized using very different techniques will be reported.

Speaker: Antonella Balerna (INFN-LNF)

Balerna_Au_nano_HigPrecConf_2021_last.pdf

10:20 Coffee break

Session: Morning #2

Convener: Alessandra Gianoncelli (Elettra Sincrotrone Trieste)

22 X-ray Absorption Spectroscopy studies on GeTe based Phase-Change Materials

Phase-change materials (PCMs), mainly based on chalcogenide alloys based on compounds lying on the GeTe/Sb₂Te₃ pseudo binary line of the Ge-Sb-Te ternary phase diagram (namely GST alloys such as GeTe, Ge₂Sb₂Te₅ …), are a promising and widely studied class of materials for the production of non-volatile Phase-Change Memories and innovative Storage Class Memories [1].
GeTe can be considered as a prototypical system of the PCM family. Therefore, this explains that it has been the subject of a huge number of studies aiming at describing its structure in order to unveil origin of the unique properties of PCMs. GeTe is also a building block of the so called Interfacial Phase-Change Memory (IPCM) where very thin layers of 0.7 nm of (GeTe)₂ are deposited alternatively with pseudo-2D Sb2Te3 layers by means of van der Waals epitaxy [2, 3].
One aspect that determines heavily the macroscopic behaviour of these materials in their amorphous state is the presence of peculiar and somehow undesired homopolar bonds like Ge-Ge. For this kind of studies, X-ray Absorption Spectroscopy (XAS) is an ideal experimental technique as it permits the analysis of the local environment of selected components of the alloy. Ge-Ge bonds are reported to play a major role in the amorphous phase of GST alloys where the presence of this anomaly has been related to be at origin of an increased crystallisation time [4]. In the case of GeTe films, a careful analysis of XAS data show that the role of Ge-Ge bonds is related to the resistance drift phenomenon that represents a major hurdle for the development of multi-level memories with PCMs [5].
In the case of structurally complex IPCMs the use of ab-initio calculated of XAS spectra from theoretical structures permitted to address the problem of intermixing between the GeTe and SbTe layers [6] as evidenced in a recent study [7].

REFERENCES

1. P. Noé et al. Semicond. Sci. Technol. 33, 013002 (2018).
2. J. Tominaga et al. Phys. status solidi – Rapid Res. Lett. 13, 1800539 (2019).
3. D. Térébénec, et al., Phys. status solidi – Rapid Res. Lett. 15, 2000538 (2021).
4. E. Carria et al. Electrochemical and Solid state Letters 14, h480 (2011).
5. P. Noé et al, J. Phys. D 49, 035305 (2016).
6. P. Kowalczyk et al., Small 14, 1704514 (2018).
7. F. d’Acapito et al., J. Phys. D: Appl. Phys. 53 (2020) 404002.

Speaker: Francesco D'Acapito (CNR)

23 SiPMs for real-time X-ray beam monitoring in transmission mode

Improving the accuracy of real-time dosimetry of intense X-ray beams at research or medical facilities requires the application of thin and compact detectors operated in transmission mode for online monitoring of the beam intensity and spatial profile.
In this context, we report on our activities to investigate the feasibility to detect high-intensity X-ray fluxes using Silicon Photomultipliers (SiPMs) exposed directly to the X-ray beam with no passive converter, which represents an unconventional and novel application for these sensors.
We have exposed SiPMs with different dimensions and microcell sizes to steady fluxes of X-rays. Our campaign of laboratory measurements and tests shows that the online readout of the DC current from the SiPM is a candidate observable that could be parametrized and calibrated to achieve a percent-accuracy long term monitoring of the beam intensity. The details and the results of the measurements, the SiPM response parametrization and the prospects for possible applications and follow-up studies will be discussed in this contribution.

Speaker: Leonello Servoli (PG)

24 The Advanced Surveyor of Transient Events and Nuclear Astrophysics (ASTENA)

The Advanced Surveyor of Transient Events and Nuclear Astrophysics (ASTENA) is a new high energy mission concept that has been proposed within the context of the European project AHEAD (Activities in the High-Energy Astrophysics Domain) that aims the promotion of synergies between the distinct national efforts in high-energy astrophysics and propose the next generation of gamma-ray observatories.
The ASTENA mission includes two instruments: 1) an array of Wide Field Monitors with Imaging, Spectroscopy and polarimetric capabilities (WFM-IS), with a large efective area and a broad energy passband (2-20 MeV), and 2) a broad-band (50-700 keV) Narrow Field Telescope (NFT) with focusing capabilities based on the use of an advanced Laue lens with unprecedented sensitivity and angular resolution.
Thanks to its increased sensitivity with respect to state-of-the-art soft gamma–telescopes in the MeV and sub-MeV energy band, ASTENA will enable the study of the so far uncovered population of low-luminosity GRBs and will afford to detect or improve existing detections with unprecedented angular resolution of gamma-ray lines of nuclear origin or from pair annihilation.
Until now, we have performed simulations to predict the telescope performance and we are currently developing the technics to build such instrument. In this presentation we will give an overview of the science motivation, a description of the telescope, and an update of the technological development.

Speaker: Miguel Moita

ASTENA.pptx

11:40 Coffee break

Session: Morning #3

Convener: Sultan Dabagov (LNF)

25 High precision kaonic atoms X-ray measurements at the DAFNE collider: the SIDDHARTA-2 experiment

The SIDDHARTA-2 experiment is ready to perform the first high precision X-ray spectroscopy measurement of the kaonic deuterium transitions to the fundamental level at the DAFNE collider of the INFN-LNF, to investigate the low-energy QCD in the strangeness sector. A dedicated experimental apparatus for high precision X-ray spectroscopy, which takes advantage of a new technology of Silicon Drift Detectors, able to operate in the high background environment of the DAFNE collider, has been realized to achieve this unprecedented goal. The contribution presents the SIDDHARTA-2 experimental apparatus, with a focus on the new technology of Silicon Drift Detectors spectroscopic response, and the preliminary results obtained during the DAFNE commisioning phase with SIDDHARTINO setup.

Speaker: Marco Miliucci (LNF)

26 Real-time detection of quantal dopamine release from single cells stimulated by X-ray irradiation

Ionizing radiation is an effective tool employed in cancer therapy and recent technological developments have led radiotherapy to a high level of accuracy. Beyond targeted effects, many studies have also highlighted the importance of off-target consequences of ionizing radiation, such as the bystander and abscopal effects [1]. Several mechanisms have been identified for the propagation of radiation effects out of the irradiated region [2-3]. However, a complete understanding of the mechanisms underlying both effects is still missing and no real-time data about signals released by cells during irradiation are presently available. Here we show the real-time simultaneous measurement of both incoming X-rays and neurotransmitter release in vitro from individual adrenal phaeochromocytoma (PC12) cells plated over a diamond based multi-electrode array and exposed to a synchrotron X ray nano-beam. Beyond identifying the critical doses corresponding to instantaneous death of individual cells, we have shown that, in specific conditions, X-rays are able to alter PC12 cell activity by promoting dopamine exocytosis, which so far was not considered as associated to X-ray irradiation [4]. Since dopamine affects tumour growth by inhibiting angiogenesis but cannot be injected at the systemic level because of its toxicity [5], further studies about the possibility to locally stimulate dopaminergic cells via X-ray irradiation should be considered as potentially attractive for a better treatment of tumours.

[1] J-P, Pouget, J.-P., Antioxid. Redox Signal. 29, 1447–1487 (2018)
[2] E. Azzam, Proc. Natl. Acad. Sci. 98, 473–478 (2001).
[3] C. Mothersill, Radiat. Res. 149, 256 (1998).
[4] M. Peters. Drug Resist. Updat. 17, 96–104 (2014).
[5] F. Picollo, et al., Nano Lett. 20, 20, 3889(2020).

Speaker: Federico Picollo (University of Torino)

27 Probing Electron Properties in ECR Plasmas using X-ray Bremsstrahlung and Fluorescence Emission

Emission spectroscopy has been long-employed as a powerful passive diagnostic tool to probe electron cyclotron resonance (ECR) plasma properties. By comparing experimentally measured spectra with suitable theoretical models, quantities of physical importance like particle density, temperature and charge state distribution can be estimated.Traditionally, optical emission spectroscopy has been used to probe cold electron properties ($T_{e}<10\,\mathrm{eV}$) [1] while X-ray bremsstrahlung spectroscopy has proved more useful for hot electrons ($T_{e}>50\,\mathrm{keV}$) [2].

Recently, phenomenological X-ray spectroscopic analyses have also been extended to include atomic line spectra, in order to deduce information about warm electrons ($T_{e}\sim2-30\,\mathrm{keV}$) and ion densities [3,4], and inner-shell ionisation rates [5]. Here we present a new numerical method capable of describing simultaneously the bremsstrahlung background as well as volumetric K-line emission spectra of plasma ions, in the range $2-20\,\mathrm{keV}$ [6], thus allowing deduction of charge particle density and electron energy distribution function (EEDF). The technique can be also used to experimentally benchmark theoretically derived anisotropic EEDFs known to exist in ECR plasmas. This will prove useful for modelling space-resolved volumetric X-ray emissions [7] as well as for validating data inputs crucial for the PANDORA project.

REFERENCES
[1] O. Tuske et al, Rev. Sci. Instrum. 75, 1529 (2004)
[2] C. Baruè, M. Lamoureux, P. Briand, A. Girard and G. Melin, J. Appl. Phys. 76, 5 (1994).
[3] G. Douysset, H. Khodja, A. Girard and J.P. Briand, Phys. Rev. E. 61, 3 (2000).
[4] J.P. Santos, A. M. Costa, J.P Marques, M.C. Martins, P. Indelicato and F. Parente, Phys. Rev. A. 82, 062516 (2010).
[5] M. Sakildien, R. Kronholm, O. Tarvainen, T. Kalvas, P. Jones, R. Thomae and H. Koivisto, Nuclear Inst. and Methods in Physics Research A, 900 (2018).
[6] D. Mascali, G. Castro, S. Biri, R. Racz, J. Palinkas, C. Caliri, L. Celona, L. Neri, F.P. Romano, G. Torrisi and S. Gammino, Rev. Sci. Instrum. 87, 02A510 (2016).
[7] R. Rácz, S. Biri, J. Pálinkás, D. Mascali, G. Castro, C. Caliri, F. P. Romano and S. Gammino, Rev. Sci. Instrum. 87, 02A741 (2016).

Speaker: Bharat Mishra (INFN - LNS)

HPXM Presentation.pdf

13:00 Lunch

Session: Afternoon #1

Convener: Maurizio Benfatto (LNF)

28 Construction and test of the Gas Pixel Detectors for the IXPE Mission

After a gap of more than 40 years since the first observations in space, the window for astronomical polarimetry in the soft X-ray band has recently reopened, thanks to the advancement in the field of gas polarimeters based on the photoelectric effect.
The NASA Imaging X-ray Polarimetry Explorer (IXPE) mission, scheduled for launch in late 2021, will bring into orbit three identical detectors that represent the latest generation of such technology, the Gas Pixel Detector, with the aim of measuring for the first time the polarization of tens of astrophysical objects like black holes, magnetars, pulsars, active galactic nuclei and supernova remnants in the energy range between 2 and 8 keV.
Here I will describe the design, assembly and test of the Gas Pixel Detectors for the IXPE mission, which was carried over, for the largest part, at the INFN facilities in Pisa. The work culminated, in early 2020, with the delivery of the flight units for integration on the satellite, which is currently being finalized.
I will also discuss the performance of the detectors, in relation to the scientific program of the mission.

Speaker: Alberto Manfreda (INFN Pisa)

gpd_test_construction.pdf

29 Applications of HAPG for high resolution spectroscopy

During the first Frascati workshop on high precision X-ray measurements, Christopher Schlesiger introduced our work on modeling the reflection properties of HAPG for X-rays. These efforts were motivated by our activities for the development of X-ray tube based spectrometers for high resolution X-ray spectroscopy, namely X-ray emission spectroscopy (XES) and X-ray absorption spectroscopy (XAS). Simulations of the response of HAPG X-ray optics played an important role for design and optimization as well as for the understanding of peak shapes, resolution effects and other spectral artifacts.
In this presentation, we will give an overview on our current and latest activities in the field of XAS and XES. Also the fundamentals of von Hamos spectroscopy with HAPG will be recapped briefly.
An overview of applications in various research projects will be given. Following the intention of the workshop, newer developments and progress in instrumentation and methodology will be presented and discussed in detail. The talk will conclude with a short overview over related projects and activities.

Speaker: Wolfgang Malzer (TU Berlin, Hardenbergstr. 32, 10623 Berlin, Germany)

30 Local structure and electronic properties of some emerging BiS2-based materials

A wide variety of emerging functional materials reveal their physical properties determined by electronic inhomogeneities appearing at varying length scales. Here, some of our recent studies using extended x-ray absorption fine structure (EXAFS) and space resolved photoemission on self-doped BiS$_2$-based superconducting systems will be presented. Space resolved photoemission shows metallic phase embedded in the stoichiometric CeOBiS$_2$ and EuFBiS$_2$. While bulk of the sample is semiconducting, the embedded metallic phase is characterized by the Fermi surface similar to the one of doped metallic BiS$_2$-based materials. The results will be discussed in connection with peculiar local structure with axial Bi-S atomic displacements being important for the self-doping.

Speaker: Naurang Saini (Sapienza Università di Roma)

15:00 Coffee break

Session: Afternoon #2

Convener: Luca Rebuffi (Argonne National Laboratory)

31 X-ray Grating Interferometry design for the 4D GRAPH-X system

Corresponding author email: alessandra.patera@to.infn.it

Keywords: X-ray grating interferometer, Talbot-Lau, phase-contrast, wave front simulation.

Purpose: The 4D GRAPH-X (Dynamic GRAting-based PHase contrast X-ray imaging) project aims at developing a prototype of an X-ray grating-based phase-contrast imaging scanner in a laboratory setting, based on the Moirè single-shot acquisition method. It is optimized for analysing moving objects, so that it could evolve into a suitable tool for biomedical applications (with main focus on lung imaging [1-4]). The system provides information about the spatial distribution of the linear attenuation coefficient, the phase-shift (i.e., the refractive index decrement) and the scattering properties of the sample (namely, the dark-field signal), generating three independent 3D images with a simultaneous acquisition [5]. Wave field simulations are performed in order to optimize the geometric parameters and construct a high resolution and sensitive imaging setup. In this work, the design and construction of a dynamic imaging setup using a conventional milli-focus X-ray source is presented.

Materials and Method: The 4D GRAPH-X system for X-ray phase-contrast imaging based on Talbot-Lau grating interferometry, installed in a radiation-protected area of the Physics Department at the University of Torino, Italy, is at the moment the only lab-setting for grating-based phase-contrast X-ray imaging in Italy. The system consists of a source, a detector and a set of three gratings: G0, G1 and G2 gratings. The X-ray source is an ordinary GE Eresco 160 MF4-R X-ray tube with a millimetric focal spot size and a tungsten anode. A 0.5 mm thick Titanium filter is inserted in front of the source in order to model the energy spectrum with a peak around the design energy (i.e., 45 keV). The detector is a flat panel with a CMOS active part with a 114 × 146 mm2 sensitive area and a 49.5 μm pixel pitch. The gratings were fabricated by bottom up electroplating of Au into Silicon structures etched by deep reactive ion etching [6]. Grating structure and inter-grating distances are defined by simulations. A schematic view of the setup is reported in Fig.1. As a specimen, a 3 cm thick and 5 cm long anthropomorphic dynamic thorax phantom, similar to the one described in [7], is under construction in collaboration with the University of Florence. The phantom simulates a male torso containing moving structures capable of reproducing realistic lung lesions movements. While the external phantom surface is 3D printed using as reference a real patient CT acquisition (and then rescaled to a small phantom size to be suitable with the 4D GRAPH-X system), internal parts are made with materials mimicking lungs, muscles and ribs density and attenuation. Water Equivalent Inserts (WEIs) simulating spherical tumors can be positioned into the lungs in different locations. An Arduino programmable board drives a step-motor to move the spheres along linear paths.

Results and discussion: Optimization by wave front simulations led to a symmetric configuration with 5.25 μm pitch at third Talbot distance and 45 keV design energy. The spectral visibility responses at 1.5 m source-to-detector distance at the three T.O. are shown in Fig. 2. The mean visibility is of the same order of magnitude in the first three T.O. (specifically, 1: 25%, 3: 22%; 5: 24%). The main sources of errors on the visibility values depend not only on the photon statistics but also on the number of phase steps, the actual phase shift and the interferometer type. In a lab-setting, it is recommended to acquire at least 7 steps to keep the error below 1% [8]. The optimized grating parameters are used in the Monte Carlo simulation in order to estimate the transmission percentage after each system element. Results show a transmission percentage of about 20% after passing through all the gratings and the phantom. The simulated system performance is being validated both using a table-top setup at PSI and at the University of Torino, as noise in phase contrast imaging is highly dependent on the visibility. The system parameters are tuned in order to investigate the potential of the setup for dynamic imaging in view of future applications in lung imaging.

Figure 1: Schematic view of the 4D GRAPH-X system.

Figure 2: Spectral visibility as a function of the energy for T.O. = 1, 3, 5. Gratings pitch: 5.25 μm at 45 keV energy.

Acknowledgment: The present work was developed in the framework of the INFN Young researchers program 4D GRAPH-X. We acknowledge the NEXTO project (progetti di Ateneo 2017), funded by Compagnia di San Paolo, and the INFN Torino mechanical services, in particular Giuseppe Scalise who provided the mechanical drawing of the system.

Bibliography:
1 Scherer K et al 2017 X-ray dark-field radiography-in vivo diagnosis of lung cancer in mice Sci. Rep. 7 402.
2 Gromann L B et al 2017a In vivo x-ray dark-field chest radiography of a pig Sci. Rep. 7 4807.
[3] Gromann L B et al 2017b First experiences with in vivo x-ray dark-field imaging of lung cancer in mice SPIE Medical Imaging (International Society for Optics and Photonics) p 101325L.
[4] Willer K et al 2018 X-ray dark-field imaging of the human lung: a feasibility study on a deceased body PLoS One 13 e0204565.
[5] Pfeiffer F et al 2006 Phase retrieval and differential phase contrast imaging with low-brilliance x-ray sources Nat. Phys.2258–61.
[6] Josell D et al 2020 Pushing the Limits of Bottom-Up Gold Filling for X-ray Grating Interferometry J. Electrochem. Soc., 167, 132504.
[7] Pallotta S et al 2018 ADAM: A breathing phantom for lung SBRT quality assurance, Phys. Med., 49:147-155.
[8] Thüring T 2013 Compact X-ray grating interferometry for phase and dark-field computed tomography in the diagnostic energy range. ETH PhD thesis.

Speaker: Alessandra Patera (TO)

32 ARIA – A VUV beamline for EuPRAXIA@SPARC_LAB

EuPRAXIA@SPARC_LAB is the new Free Electron Laser (FEL) facility under construction at the Laboratori Nazionali di Frascati of the INFN. The electron beam of EUPRAXIA@SPARC_LAB will be delivered by an X-band normal conducting linac followed by a plasma wakefield acceleration stage. It will be characterized by a small footprint and it will deliver ultra-bright photon pulses for experiments in the water window to the FEL user community [1, 2].
In addition to the Soft-X-rays beamline already comprised in the project [3], we are also considering the installation of a second photon beamline with seeded FEL pulses in the range between 50 and 180 nm. In this contribution, we will present the FEL generation scheme, the layout of the dedicated beamline and the layout and the potential applications of the FEL radiation in this long wavelength energy range. The scientific case will indeed span different experimental techniques, from absorption and photoemission spectroscopy, Raman spectroscopy and time-of-flight measurements on photo-fragmentation of molecules. This wealth of techniques finds application on molecules, biomolecules such as proteins, nucleic acids and viruses in gas phase, aerosols and adsorbed on surfaces.

[1] M. Ferrario, et al., Nucl. Instrum. Methods Phys. Res. Sect. A 909 (2018) 134. DOI: 10.1016/j.nima.2018.01.094
[2] A. Balerna, et al., Condensed Matter 4 (2019) 30. DOI: 10.3390/condmat4010030
[3] F. Villa, et al., Nucl. Instrum. Methods Phys. Res. Sect. A, 909 (2018) 294. DOI: 10.1016/j.nima.2018.02.091

Speaker: Fabio Villa (LNF)

aria beamline at HPXM 2021.pdf

33 Advances in hybrid detector development for synchrotrons and XFELs at PSI

Hybrid detectors developed at PSI are used worldwide for synchrotron and XFEL applications. They consist in a sensor absorbing the X-ray radiation, usually silicon, connected to the CMOS readout electronics, that processes the signal generated by the sensor signal on a pixel by pixel basis. This gives the advantage that both components can be optimized separately.
Single photon counting detectors are well established at synchrotrons for diffraction applications, but they also have several drawbacks. They cannot work at low energies (about 2 keV), the minimum pixel pitch is technology-limited and they require major improvements in order to sustain the high intensities provided by fourth generation synchrotron sources.
Charge integrating detectors with dynamic gain switching can provide an extended dynamic range and find applications at X-ray Free Electron Lasers as well as at synchrotrons for high flux experiments as an alternative to single photon counters, despite the challenges given by their high data throughput and their complex calibration. In low illumination conditions, analog detectors also provide information on the X-ray energy.
Moreover, despite being limited in the pixel size by the bump-bonding, it is possible to exploit charge diffusion to interpolate the photon position at the level of a few microns, combined with an energy resolution of about 1keV FWHM.
In parallel to the advances in the readout electronics, sensors with improved quantum efficiency are under development, optimizing a shallow entrance window for soft X-rays or exploiting heavier material than silicon for higher energies (e.g, GaAs, CdTe or CdZnTe).
Additionally, sensors with internal amplification (LGADs) can improve the signal-to-noise ratio of low energy photons and allow single photon counting detectors to be operated also in the soft X-ray energy range.
This presentation discusses recent advances in detector development at PSI and the challenges that we are facing due to the new X-ray sources.

Speaker: Anna Bergamaschi (Paul Scherrer Institut)

HPXM2021_Bergamaschi.pdf

16:15 Coffee break

Session: Afternoon #3

Convener: Naurang Saini (Sapienza Università di Roma)

34 Optical simulation tools in the OASYS suite and their applications to x-ray optics design

Since 2013, OASYS (ORange SYnchrotron Suite) has been developed as a versatile, user-friendly and open-source graphical environment for modeling X-ray sources, optical systems, and experiments [1]. Its concept stems from the need of modern software tools to satisfy the demand of performing more and more complex analysis and design of optical systems for 4th generation synchrotron radiation and FEL facilities. The ultimate purpose of OASYS is to integrate in a synergetic way the most powerful calculation engines available to perform virtual experiments in a synchrotron beamline. For X-ray Optics, OASYS integrates different simulation strategies via the implementation of adequate simulation tools (e.g., ray tracing [2] and wave optics packages), which communicate by sending and receiving encapsulated data [3]. The OASYS suite has been extensively used for the EBS and APS-U projects, and several new tools have been created to perform the advanced calculations needed by the optical design of the beamlines and to provide accurate specifications for the procurement of the optics [4-6].

References
[1] Rebuffi L. and Sanchez del Rio M., “OASYS (OrAnge SYnchrotron Suite): an open-source graphical environment for x-ray virtual experiments,” Proc. SPIE 10388, 130080S (2017).
[2] Rebuffi L. and Sánchez del Río M., “ShadowOui: A new visual environment for X-ray optics and synchrotron beamline simulations,” J. Synchrotron Rad. 23, 1357-1367 (2016).
[3] Rebuffi L. and Sanchez del Rio M., “Interoperability and complementarity of simulation tools for beamline design in the OASYS environment,” Proc. SPIE 10388, 1300808 (2017).
[4] Sanchez del Rio M., Celestre R., Glass M., Pirro G., Reyes Herrera J., Barrett R., da Silva J.C., Cloetens P., Shi X. and Rebuffi L., “A hierarchical approach for modeling X-ray beamlines: application to a coherent beamline” J. Synchrotron Rad. 26, 1887-1901 (2019)
[5] Rebuffi L and Shi, X. "Advanced simulation tools in the OASYS suite and their applications to the APS-U optical design," Proc. SPIE 11493, 1149303 (2020)
[6] Rebuffi L, Shi, X., Sanchez del Rio M. and Reininger, R., “A ray-tracing algorithm for ab initio calculation of thermal load in undulator-based synchrotron beamlines” J. Synchrotron Rad. 27, 1108– 1120 (2020).

Speaker: Luca Rebuffi (Argonne National Laboratory)

HPXM2021_06-09-2021_Talk_Rebuffi.pdf

35 Energy-Dispersive RIXS

In X-ray fluorescence analysis, spectra present singular characteristics produced by the different scattering processes. When atoms are irradiated with incident energy lower but close to an absorption edge, scattering peaks appear due to an inelastic process known as Resonant Inelastic X-ray Scattering (RIXS) or X-ray Resonant Raman Scattering (RRS)[1,2]. These RIXS/RRS peak presents a series of particular features; between them,a characteristic long-tail spreading to the region of lower energy. It has been recently observed that, hidden on this tail, there is valuable information about the local environment of the atom under study. In the lastyears, several works have reported a particular kindof RIXS measurements for the discrimination, determination and characterization of chemical environments in a variety of samples and irradiation geometries,even in combinationwith other spectroscopic techniques[3-8]. One of the most important features of the experimental setup reported in these works is the use of an energy dispersive low-resolution spectrometerto obtain high resolution results.In this workthenew methodology to obtain high resolution result from low resolution measurements, so-called EDIXS,is presented.Applications of EDIXS are described, Different non-conventional configurations, such as grazing incident/emission setups, micro-analysis, etc. are showed. Finally, the first test measurements using a conventional x-ray tube for characterizing oxidation states using EDIXS are presented.

Speaker: Héctor Jorge Sanchez (National University of Córdoba)

Thursday, 10 June

Session: Morning #1

Convener: Shinji Okada (RIKEN)

36 Compressive signal collection for dynamic XAFS in the home lab

X-ray Absorption Spectroscopy (XAFS) is a widely used powerful technique for obtaining elemental and chemical information in many fields such as biosciences, material sciences, catalysis and physical chemistry. XAFS utilizes a large bandwidth radiation that is tuned sequentially to capture the entire spectrum where the resolution is dependent on the monochromator bandwidth. The entire scanning of certain samples can take relatively long times and high brightness is essential for enough sensitivity. Additionally, time resolved XAFS need complex optical setups and fast signal processing techniques to resulting in a data deluge. Few of such synchrotron sources exist worldwide, with limited access due to large amount of proposals.
Ideally, one would like to have a single shot acquisition of the entire spectrum, where the entire scanning should be faster than the chemical reaction being studied. Furthermore, the source show operate at low damage intensity, without sacrificing information and the required resolution should be close to few meV. Advantageously, this method should be available in each laboratory.
Aim of this study was to develop a method, which can match as much as possible such requirements. The method mentioned relies on efficient data processing, where it is possible to compensate for the reduced complexity of the instrumentation used, with more advanced data treatment. Compressed Sensing (CS) is a well-known procedure in signal processing used to acquire and reconstruct under-sampled data sets without losing any important information about the signal. Taking advantage of the sparsity of spectral signal, the data acquisition can be dynamic, where in one case the sampling rate is varied or in the second case the acquisition time. Aided by signal processing techniques, faster and reliable data acquisition is possible with competent results.
This research shows as a proof of concept, the advantages and limitations of the compressed sensing technique and puts forward an experimental setup to acquire, in real time, XAFS signals using a laboratory X-ray source and the compressed sensing algorithm. The results from different samples show that the percentage of the acquired data directly corresponds to the accuracy of reconstruction of XAFS signal, more sampling results in more accurate reconstruction. Additionally, even with as less as 25 % of sampling , the error for reconstruction of the XAFS spectrum for different samples is less than or equal to 1% which shows with acquiring only a few amount of components, XAFS data can be accurately reconstructed for analysis.

Speaker: Yousuf Hemani (EMPA)

37 High-precision X-ray total scattering measurements using a high-accuracy detector system

The total scattering method, which is based on the measurement of both Bragg and diffuse scattering on an equal basis, is still challenging even by means of synchrotron X-rays. This is because such a measurement demands a wide coverage in scattering vector Q, high Q resolution, and wide dynamic range for X-ray detectors. There is a trade-off relationship between the coverage and resolution in Q, whereas the dynamic range is defined by the difference in X-ray response between detector channels (X-ray response non-uniformity: XRNU). XRNU is one of the systematic errors for individual channels, while it appears to be a random error for different channels. So far, the flat-field approach, which needs a uniform reference intensity, has been adopted to correct scattering data for XRNU. However, the conventional approach has failed for the case where the level of the XRNU noise was lower than a few percent because it is difficult to obtain a perfectly uniform intensity. An alternative approach, which is based on the statistical estimation of the reference intensity, has been developed to overcome the limitation.[1] We reported that the level of the XRNU noise of a microstrip detector was successfully reduced from 1% to 0.1%.[1] On the other hand, the approach has a problem with the correcting time. The acquisition of reference data took at least half a day. The long correcting time made it virtually impossible to correct scattering data for XRNU according to the detector and experimental settings. Accordingly, a significant reduction in the correcting time was required. Recently we have improved the statistical approach to reduce the correcting time from half a day to half an hour.[2] I will give a talk about high-precision X-ray total scattering measurements using a high-accuracy detector system, which facilitate electron density studies[3,4] and dual-space structure analysis[5].

References:
[1] K. Kato, Y. Tanaka, M. Yamauchi, K. Ohara, and T. Hatsui, J. Synchrotron Rad. 26, 762 (2019).
[2] K. Kato and K. Shigeta, J. Synchrotron Rad. 27, 1172 (2020).
[3] B. Svane, K. Tolborg, K. Kato and B. B. Iversen, Acta Cryst. A77, 85 (2021).
[4] A. A. Pinkerton, Acta Cryst. A77, 83 (2021).
[5] J. Beyer, K. Kato and B. B. Iversen, IUCrJ 8, 387 (2021).

Speaker: Kenichi Kato (RIKEN SPring-8 Center)

KenichiKato.pdf

38 Study of multi-pixel scintillator detector configurations for measuring polarized gamma radiation

Measurement of gamma-ray polarization is of interest in many areas of modern physics, both in fundamental and applied research. One interesting case is detection of polarized gamma radiation from positron annihilation. When the positronium decays to two gamma photons, they are created with orthogonal polarizations. It is possible to use coincidence measurements of the two photons to deduce azimuthal correlations via Compton scattering and estimate their initial polarization correlation. This information is of great interest in gamma imaging systems, such as Positron Emission Tomography, where it may be used as an additional handle to distinguish true coincidence events. In this study we used Monte Carlo simulations based on the Geant4 toolkit to model several multi-pixel detector configurations based on LYSO:Ce and GaGG:Ce scintillators. Each module consists of 64 crystals, set up in a single 8x8 matrix, where both the recoil electron and the Compton scattered photon are absorbed. We simulated positron annihilation by generating two back-to-back gamma photons of 511 keV with orthogonal polarizations, which were then detected by two detector modules. The results indicate that a pair of such detectors can observe the modulation of the relative azimuthal scattering angles. The characteristic X-rays following electron knock-out contribute to crosstalk between the crystals, hence we studied their influence on energy resolution for selected detector geometries and materials. The resulting polarimetric performance of LYSO:Ce and GaGG:Ce based configurations are compared and their application in experiments is discussed.

Speaker: Ana Marija Kožuljević (Department of Physics, Faculty of Science, University of Zagreb)

HPXM2021-PRESENTATION(1).pptx

10:20 Coffee break

Session: Morning #2

Convener: Kenichi Kato (RIKEN SPring-8 Center)

39 High sensitivity X-ray phase imaging system based on a Hartmann Wavefront Sensor

X-ray imaging is an essential tool for non-invasive assessment of various samples, both for biomedical diagnosis and non-destructive testing applications. Many technical approaches have been proposed to enhance the level of information recorded in the X-ray images. When absorption properties are very similar between two components of a sample, it makes it difficult to separate them using X-ray absorption imaging. X-Ray Phase Contrast Imaging (X-PCI) shows great capability to differentiate elements with similar absorption (Bravin, 2013).

We propose a novel, single-exposure X-ray quantitative phase imaging system based on a Hartmann Wavefront sensor (HWS). The system provides high spatial sampling (20µm without magnification) and high sensitivity (~100 nrad) over a 5 to 25 keV energy range. The system can be used to perform tomographic experiments.
Here we present the imaging system (Fig. 1a) installed at the Syrmep beamline at Elettra as well as first images obtained on reference samples. This test sample was composed of four different micro-spheres: Si (480µm in diameter), Al2O3 (500µm), quartz (350µm) and soda lime glass (700µm). Each hole in the Hartmann mask generates a bright spot on the camera and the lateral shift of the spot compared to the image without sample is proportional to the deflection generated by the sample. From two acquisitions (with and without sample), both absorption and deflections in the two transverse directions are obtained simultaneously. Since the Hartmann technology is achromatic, it also allows hyperspectral imaging. The figure illustrates the absorption in (1b) and deflections in the X and Y directions (1c and 1d respectively) generated by the samples and measured by the HWS. Our approach provides an alternative to already proposed X-PCI methods. A HWS can be used to discriminate transparent objects. Furthermore, the knowledge of object shapes, when combined to quantitative phase measurements can lead to local density measurements of complex objects, with multiple possible applications in biomedical imaging or material science.

Bravin, A., Coan P. and Suortti, P., X-ray phase-contrast imaging: from pre-clinical applications towards clinics”, Phys. Med. Biol. 58, (2013), R1-R35

Acknowledgements
This research was funded by the 3DXlight project (European Union’s Horizon 2020 research and innovation program) under grant agreement nº 851956, by the XPulse project (Région Nouvelle-Aquitaine and the European Union FEDER, FEDER/FSE Aquitaine 2014–2020), grant agreement n°3334910, LASERLAB-Europe Joint Research Activity grant agreement n°871124 and the support of Prematuration 2019 project from IP Paris. MI gratefully acknowledge the support of the Accelerator and Detector Research Program, part of the Scientific User Facility Division of the Basic Energy Science Office of the U.S. Department of Energy, under the project “Wavefront Preserving Mirrors.” This work has received funding from the European Union’s Horizon 2020 research. The FISR Project ‘Tecnopolo di nanotecnologia e fotonica per la medicina di precisione’ (funded by MIUR/CNR, CUP B83B17000010001) and the TECNOMED project (funded by Regione Puglia, CUP B84I18000540002) are also acknowledged. We acknowledge all the team at the SYRMEP beamline of Elettra for giving us access to the beamline and for their technical support.

Speaker: Ginevra Begani Provinciali (3Laboratoire d’Optique Appliquée, CNRS, ENSTA Paris, Ecole Polytechnique IP Paris)

40 The TRILL project: increasing the technological readiness level of Laue lenses for hard X/soft Gamma-ray astronomy

Hard X/soft Gamma-ray astronomy is a key field for the study of important astrophysical phenomena such as the electromagnetic counterparts of gravitational waves, gamma-ray bursts, black holes physics and many more. However, the spatial localization, imaging capabilities and the sensitivity of our measurements are strongly limited for the energy range >70 keV due to the lack of focusing instruments operating in this energy band. A new generation of instruments able to focus hard X-/ soft gamma rays is necessary to shed light on the nature of astrophysical phenomena which are still unclear due to the limitations of current direct view telescopes.
Laue lenses can be the answer to those needs. A Laue lens is an optical device consisting of a large number of properly oriented crystals which are capable, through Laue diffraction, to focus the radiation into the common Laue lens focus. In contrast with the grazing incidence telescopes commonly used for soft X-rays, the Laue transmission configuration allows us to obtain a significant sensitive area even at energies of hundreds of keV.
At the University of Ferrara, we are actively working on the development of the Laue lens technology with the TRILL (Technological Readiness Increase for Laue Lenses) project. TRILL is dedicated to the advancement of the technological readiness of Laue lenses by developing the first prototype of a sector of a broad energy-band Laue lens made by cylindrically bent crystals of Germanium, which are glued to a quartz frame with a low-shrinkage, space-qualified glue. In this talk we present the technological advancements which mainly concerns the crystals preparation method, its repeatability over a large number of crystals and the crystals assembly technique. We also present the criticalities and alternative designs for orienting a plurality of crystals and for bonding them on a common substrate.

Speaker: Lisa Ferro (Università degli Studi di Ferrara)

HPXM2021_Lisa_Ferro_TRILL.pptx

41 X-ray micro-tomography as a method to distinguish and classify natural and cultivated pearls

Digital radiography and computed tomography are two fundamental diagnostic techniques in different fields of research, including Cultural Heritage studies and gemmology; the application of these physical methods of investigation has gained considerable importance thanks also to their non-invasiveness. It is in fact of great importance to obtain information on the "invisible" parts of a work of art, of an artifact or, more generally, of any sample, without compromising its integrity. In particular, with X-ray CT the three-dimensional reconstruction of an object is performed starting from 2D projections acquired at different angles, in order to obtain useful knowledge on the entire volume of the object.
The presented work has been mainly focused on micro-tomographic analysis, developing a custom instrumentation based on a microfocus X-ray source and a TDI X-ray detector, both from Hamamatsu, and a high-precision rotary stage. The setup geometry has been adapted taking into account the necessity of fast measurements (maximum 2 hours) and the need of a high resolution (in the order of 10 micrometers).
The project, developed within the Physics Department of the University of Turin and INFN, in collaboration with the spin-off TecnArt S.r.l. and with the R.A.G. gemmological laboratory in Turin, concerned the micro-tomographic study of natural and cultivated pearls with the aim of developing an investigation methodology for the analysis and classification of different types of pearls, some of them belonging to different precious jewels from private collections. The distinction between natural (naturally produced by marine or freshwater pearl molluscs) and cultivated (produced as a result of human intervention) pearls has never been simple and it has recently become even more difficult with the large number of cultivated pearls sold nowadays. In this case, the use of micro-tomography as a diagnostic technique can provide clear evidence on their origin thanks to the possibility to visualize their internal structure and to study the grey levels variation in the images (due to the different absorption of X-rays by materials in the object).
The investigations, carried out on a total of 22 heterogeneous types of pearls (both free-standing and part of precious jewellery, such as two pairs of earrings and a brooch), allowed to establish the origin of the pearls (natural or cultivated) or to confirm/deny it if a hypothesis was already expressed, and to highlight as well the cultivation methodology used case-by-case. Furthermore, it was possible to ascertain how large and varied the market for cultured pearls is nowadays and how difficult is, in some particular cases, their attribution to a certain origin.

Speaker: Luisa Vigorelli (Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino - Dipartimento di Fisica, Università degli Studi di Torino - INFN, Sezione di Torino)

Vigorelli_HPXM2021_ppt.pptx

11:40 Coffee break

Session: Morning #3

Convener: Johann Marton (Stefan Meyer Institute)

42 X-ray instrumentation to observe the hot and energetic Universe

What instrumention is needed to observe the X-rays generated in the hot Universe?
The next generation of wide-area, sensitive X-ray surveys designed to map the hot and energetic Universe has arrived, thanks to eROSITA (extended ROentgen Survey with an Imaging Telescope Array), the core instrument on the Russian-German Spektrum-Roentgen-Gamma (SRG) mission. eROSITA's high sensitivity, large field of view, high spatial resolution and survey efficiency is bound to revolutionize X-ray astronomy and deliver large legacy samples for many classes of astronomical objects in the energy range 0.2-8 keV. I will present an overview of the instrument capabilities, the current status of the mission, and a few selected early science results.

Speaker: Peter Predehl (Max-Planck-Institut für extraterrestrische Physik)

X-ray instrumentation to observe the Universe.pdf

43 Soft X-ray microscopy techniques at TwinMic - Elettra

Soft X-ray microscopy is a well-established and powerful tool often used for the scientific study of samples of interest at micrometric and sub-micrometric length scales in several research fields, from Life Sciences, to Materials Science, Environmental Science and Cultural Heritage. Here we present the capabilities of the TwinMic soft X-ray Microscopy end-station installed at the Elettra synchrotron, illustrating recent scientific achievements and describing novel uses and imaging development.

Speaker: Gianoncelli Alessandra (Elettra Sincrotrone Trieste)

44 X-ray imaging and space resolved spectroscopy of ECR plasmas in compact magnetic traps

In the frame of the PANDORA (Plasmas for Astrophysics, Nuclear Decays Observation and Radiation for Archaeometry) project, aiming at measuring for the first time in-plasma nuclear β-decays of astrophysical interest, an innovative multi-diagnostic approach to correlate plasma parameters to nuclear activity has been proposed [1, 2]. This is based on several detectors and techniques (Optical Emission Spectroscopy, RF systems, Interferopolarimetry) and here we focus on high resolution spatially-resolved X-ray spectroscopy, performed by means of a X-ray pin-hole camera setup operating in the 0.5-20 keV energy domain. We here present the setup installed at a 14 GHz Electron Cyclotron Resonance (ECR) ion source (ATOMKI, Debrecen), including the description of the multi-layered collimator enabling measurements with a plasma heated by hundreds of watts. The achieved spatial and energy resolution were 0.5 mm and 300 eV at 8 keV, respectively [3]. The innovative analysis algorithm for Photon-Counted images permits to investigate the local plasma emitted spectrum in a High-Dynamic-Range (HDR) mode, by distinguishing fluorescence lines of the materials of the plasma chamber (Ti, Ta) from plasma (Ar) fluorescence lines. This method thus allows a quantitative characterization of warm electrons population in the plasma (and its 2D distribution) which are important for ionization, and to estimate local plasma density and spectral temperatures. Both stable and turbulent plasma regimes have been investigated. The setup and algorithms are now under update including fast shutters and trigger systems in order to allow space and time-resolved plasma spectroscopy during transients, stable and turbulent regimes.

References
[1] D. Mascali et al., EPJ Web of Conf., 227 (2020) 01013
[2] E. Naselli et al., JINST 14 (2019) C10008
[3] S. Biri et al., JINST 16 (2021) P03003

Speaker: Eugenia Naselli (LNS)

13:00 Lunch

Session: Afternoon #1

Convener: Andrea Zappettini

45 XSpectra®: an Advanced Technology for Improving Real-Time Inspections on Food Production-Lines

The very big need for an improvement in the efficacy of real-time foreign-bodies and non-conformities inspection on production lines in the food sector has pushed Xnext towards the development of a novel patented inspection technology, called XSpectra®. The technology architecture is modular, each acquisition module being equipped with a 128 CdTe pixels 1D array and covering a linear inspection area of 10 cm. The current signals generated by the pixels are read-out and pre-processed by proprietary full-custom Front-End ASICs, whose output signals are then digitized and processed by a full-custom Multi Channel Analyzer providing for radiation spectrum reconstruction. Spectral data of all the acquisition modules is thus conveyed over a proper network interface towards a back-end processor running advanced Neural Network algorithms performing both spectral image reconstruction and foreign bodies detection. Experimental results have shown the XSpectra® capability to operate with a sensitivity down to about 9 keV of energy at photon-rates up to several millions of photons per second. A line-width of about 5.5 keV FWHM has been measured, at room temperature, on the 59.54 keV line of an Am241 very-low activity isotopic source. The system spectral non-linearity error has been measured to be within ±0.5% in the energy range 25 keV - 100 keV. Real-world industrial test-cases have demonstrated the effective superiority of XSpectra®, with respect to other conventional inspection technologies, in detecting low-density foreign bodies inside food products.

Speaker: Daniele Macera (Xnext S.p.A.)

46 Plasma-generated X-ray pulses: betatron radiation opportunities at EuPRAXIA@SPARC_LAB

EuPRAXIA is the first European project that develops a dedicated particle accelerator research infrastructure based on novel plasma acceleration concepts and laser technology. It focuses on the development of electron accelerators and underlying technologies, their user communities, and the exploitation of existing accelerator infrastructures in Europe.
Within this framework, the Laboratori Nazionali di Frascati (LNF) will be equipped with a unique combination of a high brightness GeV-range electron beam generated in a state-of-the-art X-band RF linac, a 0.5 PW-class laser system and the first 5th generation Free Electron Laser (FEL) source driven by a plasma accelerator. Wiggler-like radiation emitted by electrons accelerated in laser-plasmas wakefields gives rise to brilliant, ultra-short X-ray pulses, called betatron radiation. Some experience in this field was already gained at the FLAME laser facility of the INFN Frascati National Laboratory were betatron radiation was measured and characterized [1-3].
In this talk, we will describe the main features of the EuPRAXIA betatron radiation and will highlight the opportunities offered by its brilliant femtosecond pulses for ultra-fast X-ray spectroscopy measurements, as X-ray pump pulses for FEL experiments and as an ancillary tool for designing and testing FEL instrumentation and experiments.

[1] A. Curcio et al. Phys. Rev. Accel. Beams 20 (2017) 012801. DOI: 10.1103/PhysRevAccelBeams.20.012801
[2] A. Curcio, et al., Nucl. Instrum. Methods Phys. Res. Sect. B 402 (2017) 388. DOI: 10.1016/j.nimb.2017.03.106
[3] F.G. Bisesto, et al. Nucl. Instrum. Methods Phys. Res. Sect. A (2017): 388. DOI:/10.1016/j.nima.2018.02.027

Speaker: Francesco Stellato (ROMA2)

47 Confocal fluorescence microscopy and confocal Raman microspectroscopy of X-ray irradiated LiF crystals

X-ray detectors based on the photoluminescence of radiation-induced color centers (CCs) locally produced in lithium fluoride (LiF) crystals will be discussed. Among the peculiarities of LiF-based detectors, noteworthy ones are their very high intrinsic spatial resolution across a large field of view, wide dynamic range and versatility. LiF crystals irradiated with monochromatic X-rays (8 e 16 keV) at Anka synchroton light source (Karlsruhe, Germany) and with the broadband white beam spectrum of the synchrotron bending magnet have been investigated with optical spectroscopy, laser scanning confocal microscopy in fluorescence mode and confocal Raman microspectroscopy. The penetration depths in LiF of the X-rays used for irradiation allowed to produce volumetric distributions of CCs in the crystals. 3D characterizations of the X-ray-induced CC distributions have been performed with both confocal techniques. The combination of capability of a LiF crystal to register volumetric X-ray mapping with the optical sectioning operations of the confocal techniques has allowed performing 3D reconstructions of the X-ray colored volumes and it could provide advanced tools for 3D X-ray detection.

Speaker: Francesca Bonfigli (ENEA C.R. Frascati, Fusion and Technologies for Nuclear Safety and Security Dep., Photonics Micro- and Nano-structures Laboratory, FSN-TECFIS-MNF,V. E. Fermi, 45, 00044 Frascati (Rome), Italy)

15:00 Coffee break

Session: Afternoon #2

Convener: Héctor Jorge Sanchez

48 X-ray spectroscopy of kaonic atoms with TES-based microcalorimeters

Kaon is the lightest meson containing a strange quark, and would play an important role to understand a high-density nuclear matter such as neutron stars. To extract the strong interaction between an anti-kaon and a nucleus at low energies, X-ray spectroacopy of kaonic atoms, Coulomb bound systems of a negatively-charged kaon, a nucleus, and electrons, are quite unique.
We performed a kaonic atom X-ray measurement at Japan Proton Accelerator Research Complex (J-PARC; Tokai, Japan) using a transition-edge-sensor(TES)-based X-ray spectrometer. The TES spectrometer has an excellent energy resolution, and is now a matured technology for various field of appplications. We used a 240-pixel TES array of about 23 mm$^2$ collecting area with 4 um thick Bi absorbers, developped by NIST in US. Our project was the first case to use the TES spectrometer in a hadron-physics experiment at a charged-particle beamline.
Following a demonstraion experiment in a pion beamline at PSI in 2014, and a commsioning experiment at J-PARC in 2016, we performed a scientific campaign to measure the 3d-2p X-ray lines of kaonic helium-3 and helium-4 (6.2 keV and 6.4 keV, respectively) in 2018. We successfully observed X-ray lines from kaonic atoms with a resolution of $\sim$6 eV in FWHM.
Here we will describe the details of our experimetal method and present an overview of the data analysis and the results. Especially, we will focus on how we dealed with challenges unique in our TES application at a charged-particle beamline.

Speaker: Tadashi Hashimoto (Japan Atomic Energy Agency)

49 VOXES: a millimetric effective source size HAPG crystals based Von Hamos spectrometer as a tool for extreme precision exotic atom spectroscopy

One of the more quoted methods to perform high energy resolution X-ray measurements is given by the Bragg spectroscopy. The requirement on the size of the target not to exceed tens of microns represents the major hindrance in its use when the photons emitted from extended sources (millimetric) need to be measured. Also, the typical very low efficiencies og Bragg spectrometers prevent them from being used in sevearl applications. To overcome this problem the VOXES collaboration at INFN National Laboratories of Frascati developed a prototype of a high resolution VOn hamos X-ray spectrometer using HAPG (Highly Annealed Pyrolytic Graphite) mosaic crystals. This technology allows the employment of extended isotropic sources and makes possible its application in several physics fields as the exotic (kaonic) atoms precision measurements. The performance of this device has been explored in terms of reflection efficiency and the results for a rho = 206.7 mm cylindrically bent HAPG crystal using CuKa1,2 and FeKa1,2 XRF lines compared with the simulated data will be presented. This kind of study is fundamental since permits to retrieve information on the signal collection efficiency in the energy range in which the standard calibration procedures cannot be applied.

Speaker: Veronica De Leo (Università degli Studi di Roma "La Sapienza")

pres_xray_conf_0906.pdf

50 Mmpxrt - New X-ray tracing code not only for mosaic crystal spectrometers.

A new X-ray tracing code became available for general use last year. [1] It is dedicated to study and design X-ray crystal optics, with a special focus on mosaic crystal spectrometers. Its main advantage is that it includes a detailed and benchmarked algorithm to treat mosaic crystals, especially HOPG and HAPG. It is preferentially made to study crystal spectrometers, therefore their implementation is very straightforward and includes the automated evaluation of their performance. It can, however, be used universally to study other Bragg crystal based instruments, such as monochromators. In last years it was, for example, used to design an HAPG mirror to reflect the Small Angle X-ray Scattering (SAXS) in the harsh environment of high intensity laser interaction at the European XFEL laboratory. [2] Several use cases of the code will be presented.

[1] M.Šmíd et al., X-ray spectrometer simulation code with a detailed support of mosaic
crystals. https://doi.org/10.1016/j.cpc.2020.107811

[2] M.Šmíd et al., Mirror to measure small angle x-ray scattering signal in high energy density experiments. https://doi.org/10.1063/5.0021691.

Speaker: Dr Michal Šmíd (Helmholtz Zentrum Dresden Rossendorf)

51 Talk competition winners announcement & closing remarks

Speaker: Alessandro Scordo (LNF)