Particle beams of high energy and spin-polarization are necessary for various experiments, i.a. in order to test the Standard Model of particle physics. Over the last few years, several setups for spin-polarized electron and proton beams from laser-plasma interaction have been proposed. We present a mechanism based on magnetic vortex acceleration, where the interaction of a single laser pulse...
In a hybrid LWFA-driven PWFA (LPWFA) electron beams from a laser wakefield acceleration (LWFA) stage are utilized to drive a plasma wave in a subsequent plasma wakefield acceleration (PWFA) stage for acceleration of witness electron bunches to high energies. This concept allows for the exploration of PWFA-physics in a compact setup and harnessing the advantages of both plasma acceleration...
We report on the conceptual design of an amplification chain based on Tm-doped gain medium [1], for solid-state, ultra-short CPA laser pulses, aiming at high-efficiency, kHz repetition rate, high peak power and kW-scale average power, with emission wavelength around 2 µm. A multi-pass configuration is presented, with three stages, with 4% doped Tm:Lu2O3 ceramic thin discs, lateral (edge) [3]...
Recent experiments have shown the capability of Laser wakefield accelerated (LWFA) electron beams to be suitable driver beams for a particle driven wakefield acceleration (PWFA) stage. The high peak current and short duration of such beams open up the possibility of operating the PWFA stage at density ranges in the order of $10^{18} \mathrm{cm}^{-3}$. Here, femtosecond optical probing of the...
We study the propagation of an electron bunch travelling within a proton bunch through a plasma density ramp. Because the proton bunch density in the ramp is higher than the plasma density, the bunch generates a high density, on-axis plasma electron filament. This filament is defocusing for the electron witness bunch that can therefore be lost along the ramp. At AWAKE we have measured this...
Innovative particle accelerators based on plasma technology allow a drastic reduction in size, thanks to the high acceleration field established inside plasmas, created and confined by particular devices. Plasma wake-field acceleration experiments are performed at the SPARC LAB test facility by using devices consisting in gas-filled capillaries, in which the plasma formation is achieved by...
Laser and plasma wakefield acceleration is a two-stage process. Electron bunches are accelerated to relativistic velocities and then tailored to specific characteristics. In depth understanding and control of the involved acceleration mechanisms is crucial. Femtosecond probing gives insight into plasma dynamics during acceleration. Spectrally broadened and compressed probe pulses with a length...
FLASH Therapy, an innovative technique in radiation therapy, has shown to dramatically spare normal tissue toxicities in multiple organs maintaining the efficiency as conventional irradiation to inhibit tumor growth. The therapy has been successfully tested using microsecond pulses of low energy electrons, using intrapulse dose rate in the range 106–107 Gy/s, time-averaged dose rate >100 Gy/s,...
Laser plasma acceleration [1] provides several advantages compared to conventional radio-frequency accelerators for electron source injectors: high accelerating gradients up to hundreds of gigavolts per meter (compactness) and short duration electron beams. However, the control of quality and stability of the produced electron bunches remains a challenge.
In this report we focus on the...
Laser-plasma accelerators are rapidly developing to produce high-quality sub-GeV electron beams capable of Free Electron Laser (FEL) operation. Their reduced size and cost with respect to conventional accelerators can widely spread the use of particle beams in medical physics and industry. Although multi GeV electron energies were demonstrated, more work is needed to establish high quality...
We study experimentally hosing [1] of a long proton bunch in plasma in AWAKE. We induce this process with misalignment between the trajectories of a preceding short electron bunch and that of the proton bunch. We observe hosing as transverse oscillation of the proton bunch centroid position in the plane of misalignment at the period of the wakefields. Self-modulation (SM) occurs in the...
Laser-wakefield acceleration (LWFA) has been investigated as a possible route towards a compact, high-gradient replacement for current RF-based accelerator technology. LWFAs recently made huge progress in terms of achievable energy (multi-GeV), charge (~nC), current (up to 100 kA) and spectral charge density (up to 20pC/MeV). However, due to the sensitive dependence on driver fluctuations and...
Beam-driven plasma-wakefield acceleration has the potential to reduce the building cost of accelerator facilities, with large accelerating fields that are orders of magnitude greater than those of radio-frequency cavities. Sustaining strong decelerating fields for the driver and strong accelerating fields for the trailing bunch across long plasma stages will be key to demonstrating high energy...
For the creation of matter-antimatter pairs from the quantum vacuum via the Breit-Wheeler effect, an intense laser and energetic γ-rays need to interact. At the Stanford Linear Accelerator Center the Breit-Wheeler experiment in the perturbative regime has been accomplished in 1997 but was never implemented in the non-perturbative regime. At the moment, this experiment is in preparation in a...
Laser-Ion acceleration typically uses thin foils as targets, where the density is typically a few hundred times the critical density (n_c ). Targets with just a few times n_c constitute an interesting target system for laser plasma acceleration. Unfortunately, these densities are hard to achieve in experiment. In this poster we present an exploding foil experiment, were we pre-expand a thin...
With the possibility of using high-power laser systems as drivers for particle acceleration, laser diagnostics becomes even more important in that field.
Knowledge of spatial-temporal couplings such as pulse-front tilt or curvature is important to determine the focused intensity of high-power lasers. Common techniques to determine these couplings are either qualitative or complex to set up....
A laser wakefield experiment was performed at the Lund Laser Centre with the support of ARIES Transnational Access programme. In the context of the EuPRAXIA project it aimed to explore possible control mechanisms over laser-plasma coupling and the resulting trapping and acceleration dynamics of the produced electron bunches. Three main experimental parameters which have a large impact on the...
Ultrafast shadowgraphy with transverse few-cycle probe pulses has enabled the observation of details of the laser-plasma interactions with unprecedented temporal (fs) and spatial (µm) resolution. However, in previous studies, probe pulses spanning a broad frequency spectrum have been commonly used to achieve an acceptable signal-to-noise ratio because of the limit of probe pulse energy....
A Laser-Wakefield Accelerator can produce electrons in the MeV range just over a few millimetres. However, due to their finite energy spread and divergence the applications of these electrons become limited. By tailoring the plasma density, the phase can be manipulated and hence gaining control of the bunch energy spread and divergence. Here, the properties of 100 MeV shock-assisted...
The LUXE (Laser Und XFEL Experiment) project at DESY Hamburg aims to measure processes in the strong-field quantum electrodynamics regime with high precision by colliding electrons or a high-energy photon beam with a high-power, tightly focused laser beam at a repetition rate of 1Hz. Simulations [LUXE CDR, arXiv:2102.02032 [hep-ex]] predict that the probability of pair production responds...
The multi-pulse laser wakefield acceleration (MP-LWFA) scheme provides a route for GeV-scale accelerators operating at kilohertz-repetition-rates driven by picosecond-duration laser pulses, such as those available from thin-disk lasers, which are modulated to be resonant with the plasma wave. We recently published theoretical work proposing a new scheme of GeV accelerator based on MP-LWFA. In...
Simultaneous space-time focusing occurs when a transversely-chirped ultrashort laser pulse is focused using a conventional lens. Before the lens different frequencies are separated radially so that at any point on the transverse plane the local bandwidth is relatively low. These frequencies are brought together downstream of the lens as they approach the focus. As the spatial overlap between...
THz radiation with sufficient intensity finds various applications, including pump-probe experiments in free-electron lasers, wireless communication, material analysis, process control in biology, pharmacy, and medicine. The most common process for generating THz radiation is by optical rectification, in which laser pulses incident to a nonlinear crystal produce broadband THz pulses. A compact...
Dielectric laser accelerator (DLA) has emerged as a miniaturised and cost-effective tool for particle acceleration. DLAs have proved to be a promising candidate for GeV/m acceleration gradient within the damage threshold of the materials used. However, the emittance growth and energy spread increase at higher particle energies and limit the realistic applications. Here we present the numerical...
A novel model of space charge forces is proposed for a low-energy (γ~1) bunch with arbitrary charge distribution in RF-guns. By exploiting Green function method, it is possible to develop an analytical approach and derive expressions of self-induced forces for any transverse and longitudinal bunch distribution. The model is accurate also in the approximation of low energy beams, when the 3D...
The past years have seen a growing interest in plasma-based accelerator technology since it provides a route to more compact, ecological yet powerful accelerators. However, even well-established acceleration techniques are only effective with particles traveling at speeds close to the speed of light (relativistic particles), leading to the exclusion of heavier particles, e.g. muons from the...
The dielectric accelerator is one of the most advanced accelerator concept, in which the ultra high accelerating field can be excited by either optical to infrared laser or ultrashort relativistic electron bunches. The beam driven dielectric wakefield accelerators (DWFA) make use of the electromagnetic Cherenkov radiation (wakefield) from the electron bunches that pass through the...
Building small scale particle accelerators on a photonic chip may lead to revolutionary applications of particle accelerators, including new minimally invasive beam irradiation tools for physicians. All individual elements required for particle accelerators on a chip have been demonstrated, but a beam confinement scheme matched to the nano- and micrometer size was needed. By alternately...
EuPRAXIA@SPARC_LAB is a new Free Electron Laser (FEL) facility that is currently under construction at the Laboratori Nazionali di Frascati of the INFN. The electron beam driving the FEL 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 include two different plasma-driven photon beamlines....
Laser-plasma accelerators (LPA) are one the verge of becoming drivers for real-world science applications. However, in order to be considered serious alternatives to conventional machines they need to be able to provide competitive quality and versatility of the electron beam parameters as requested by potential applications. As shown by numerous experiments in the past LPAs are in principle...
Comb electron beams are fs and high brightness electron bunches used to drive plasma accelerating modules. An ultra-relativistic beam of charged particles (the driver) through a plasma generates a wake of charge density useful for accelerate a witness beam (Particle driven WakeField Acceleration - PWFA). The witness dynamics control is fundamental to achieve the optimum transverse and...
Plasma-wakefield accelerators provide acceleration gradients several orders of magnitude larger than conventional accelerators and as such, represent a promising technology for reducing the footprint of future particle accelerators. The luminosity in colliders and the brilliance in free-electron lasers, scales with the repetition rate at which the accelerator operates. Therefore, repetition...
The self-modulation instability (SMI) is instrumental for single-stage plasma wakefield accelerator concepts with long, high-energy drive bunches such as the AWAKE experiment. It provides a self-consistent mechanism to reach high-amplitude wakefields despite the driver's length, which would otherwise not excite the plasma resonantly.
In recent demonstrations of acceleration with a...
The applications envisioned for advanced linear accelerator-based facilities rely on the production of intense particle beams delivered at high repetition rates. Indeed, the demanding brightness and luminosity foreseen by electron driven radiation sources and linear colliders, respectively, imply the coexistence of high peak currents and small transverse emittances. The acceleration of such...
Modeling plasma wakefield accelerators is computationally challenging. Using cost-reducing algorithms like the quasi-static approximation allows for efficient modeling of demanding plasma wakefield accelerator scenarios. In this work, the latest highlights of the performance-portable, 3D quasi-static particle-in-cell (PIC) code HiPACE++ [1] are presented. The code applies modern HPC practices...
Over the past decade, many experiments showed that interactions of relativistic laser pulses with targets whose geometrical features are comparable to the laser wavelength can result in increased energy coupling between the laser field and the target electrons.
Several different models were suggested to explain this phenomenon. However, unveiling the details of these interactions through...
We explore a novel simulation route for Plasma Wakefield Acceleration (PWFA) by using the computational method known as the Lattice Boltzmann Method (LBM). LBM is based on a discretization of the continuum kinetic theory while assuring the convergence towards hydrodynamics for coarse-grained fields (i.e., density, velocity, etc.). LBM is an established numerical analysis tool in computational...
The optimisation of electron beams accelerated by laser driven wakefield in plasma relies on the identification of the optimum plasma and laser properties for a specific regime of acceleration. The influence of laser symmetry around focus on the electron properties was investigated to understand recent experimental results in the case of ionisation injection in gas cells.
In order to...
A particle bunch propagating through plasma will induce a non-linear response when $n_b \gg n_{e0}$ [1]. A positively charged bunch will attract plasma electrons, which will flow-in to the propagation axis, creating a filament [2]. This will sustain defocusing fields for negatively charged particles.
In the Advanced Wakefield Experiment (AWAKE) [3], in which a long proton bunch drives high...
Interest is growing around developing techniques to shape the wavefunction of electrons.
We propose to use the time-dependent electromagnetic fields of ultrashort laser pulses to control the quantum-mechanical phase of electron pulses. We present a theoretical model showing that the ponderomotive interaction between electrons and a high-intensity strongly-focused laser beam can be used to...
The state of the art in terms of Plasma Wakefield Acceleration simulation accuracy are Particle in Cell (PIC) codes, based on a kinetic model which requires hard numerical integration and execution times of hundreds of hours on processors clusters for centimetre-long simulations. During my Master's thesis a computationally lighter model was developed, able to accurately reproduce the most...
New laser facilities will reach intensities of $10^{23} \text{W cm}^{-2}$. This advance enables novel experimental setups in the study of laser-plasma interaction. In these setups with extreme fields quantum electrodynamic (QED) effects like photon emission via non-linear Compton scattering and Breit-Wheeler pair production become important.
We study high-intensity lasers grazing the...
Energy-recovery linac (ERL) light sources facilities based on superconducting (SC) cavities are deemed as ones of the most promising techniques in the future of accelerator physics. Running in a continuous wave (CW) mode with a high repetition rate, the ERL we are addressing in this study exploits a two-pass two-way mechanism, where the energy endures in the beam after being used, then...
We demonstrate the divergence reduction of laser driven wakefield accelerated electron beams using a compact plasma lens in a single stage setup. We modify the gas density profile of a super sonic gas jet and create a shallow second density bump, which serves as a passive plasma lens, using a small ($<1$cm$^3$) metal wedge. The plasma lens decreases the electron beam divergence from averaged...
Laser-plasma accelerators (LPAs) outperform current radiofrequency technology in acceleration strength by orders of magnitude. Yet, enabling them to deliver competitive beam quality for demanding applications, particularly in terms of energy spread and stability, remains a major challenge. Here, we report on a recently published method that combines bunch decompression and active plasma...
We use Galilean transformation to the co-moving coordinates s=x, ξ=x−ct. This allows to overcome the huge scale disparity otherwise present in wake field simulations. Different from the standard quasi-static codes, the new Galilean PIC code accurately simulates the laser pulse wave structure, because the full set of Maxwell's equations is solved. The code treats all numerical macroparticles...
The use of accelerated electrons from a laser wakefield accelerator (LWFA) as drivers of a plasma wakefield stage (PWFA) provides compact PWFAs that can serve as a test bed for the efficient investigation and optimization of PWFAs and their development into brightness boosters. Such hybrid accelerators have been experimentally realized at HZDR and LMU to study novel injection schemes. To...
In the framework of both EuAPS and SAMOTRACE projects funded by the PNRR Italian program, a new high-power laser facility called “I-LUCE” (INFN Laser indUced radiation acCEleration) will be realized at LNS-INFN. Thanks to the use of the latest available technology, the system will be able to amplify light with a power of 500 TW, with a fs duration, and with a repetition rate of 1Hz. This will...
Laser-plasma accelerators can generate GeV electron beams in an ultra-compact, cm-scale setup, but have yet to demonstrate sufficient beam quality and stability for demanding applications. To overcome this challenge, broad optimization of the accelerator design with numerical simulations is essential. However, due to the high computational cost of general particle-in-cell simulations,...
This poster presents openPMD, an open and F.A.I.R. standard for particle-mesh data, and its impact in heterogeneous scientific workflows.
Particle accelerator codes need to span various time and length scales, leading to data processing pipelines consisting of multiple heterogeneous codes.
Standardization of physical data helps bridging the different models with a commonly-understood markup,...
Discharge capillaries are an essential plasma-source for a wealth of different applications in plasma-based accelerators. The long, uniform plasma profiles have been pivotal in both LWFA and PWFA experiments alike. The repetition rate of such sources has been limited to 1-10 Hz, far below the required 10 kHz to MHz of a plasma-based collider or FEL. Development of high repetition rate...
The drivers for laser plasma accelerators (LPA) are typically based on Ti:Sa technology, which is limited to repetition rates in the lower Hz range for high energies and to average powers of ~100 W. In contrast, modern Yb:YAG thin disk laser technology offers a magnitude higher average powers and repetition rates in the kHz range, combined with a high electrical-to-optical efficiency. The...
Beam-driven plasma-wakefield acceleration is a promising avenue for the future design of compact linear accelerators with applications in high-energy physics and photon science. Meeting the luminosity and brilliance demands of current users requires the delivery of thousands of bunches per second – many orders of magnitude beyond the current state-of-the-art of plasma-wakefield accelerators,...
With the development of chirped-pulse amplification ultra-short lasers with femtosecond pulse durations have become readily available and are used in numerous applications such as material processing or plasma-based accelerators. In most cases, these lasers are focused to small spot sizes, exceeding intensities of $10^{13}\;W/cm^2$ and thus the ionization threshold in most materials. As this...
Laser-plasma acceleration (LPA) promises compact sources of high-brightness electron beams for science and industry. However, transforming LPA into a technology to drive real-world applications remains a challenge. Machine learning techniques could prove decisive in further understanding and improving the performance of these machines. Here, we discuss the application of supervised learning to...
The FLASHForward experimental facility is a test-bed for beam-driven plasma-wakefield (PWFA) research and development, with a view towards both photon-science (e.g. FELs) and high-energy-physics applications (e.g. linear colliders). The facility benefits from the FEL-quality electron bunches provided by the FLASH linac to drive a wakefield in a plasma produced inside a windowless gas cell with...
Traveling-wave electron acceleration (TWEAC) is an advanced laser-plasma accelerator scheme, which is neither limited by dephasing, nor by pump depletion or diffraction. Such accelerators are scalable to energies beyond 10 GeV without the need for staging and are candidates for future compact electron-positron colliders based on existing CPA lasers.
Requiring to model a large plasma volume in...
Developing new methods for tailoring the phase-space distribution of electron beams is a challenging and essential task in next-generation particle accelerators, compact x-rays sources, and ultrafast electron microscopy. RF-cavities are routinely employed in accelerator science to manipulate the electrons’ phase-space. This contribution shows the use of a miniaturized RF-cavity to chop the...
