Conveners
WG1 - Electron beams from plasmas
- Edda Gschwendtner (CERN)
- Victor Malka (LOA)
WG1 - Electron beams from plasmas
- Edda Gschwendtner (CERN)
- Victor Malka (LOA)
WG1 - Electron beams from plasmas
- Victor Malka (LOA)
- Edda Gschwendtner (CERN)
WG1 - Electron beams from plasmas
- Edda Gschwendtner (CERN)
- Victor Malka (LOA)
WG1 - Electron beams from plasmas
- Victor Malka (LOA)
- Edda Gschwendtner (CERN)
WG1 - Electron beams from plasmas
- Edda Gschwendtner (CERN)
- Victor Malka (LOA)
WG1 - Electron beams from plasmas
- Victor Malka (LOA)
- Edda Gschwendtner (CERN)
WG1 - Electron beams from plasmas
- Victor Malka (LOA)
- Edda Gschwendtner (CERN)
Dr
Edda Gschwendtner
(CERN)
14/09/2015, 16:00
WG1 - Electron beams from plasmas
talk
The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV proton...
Dr
Min Chen
(Shanghai Jiao Tong University)
14/09/2015, 16:30
WG1 - Electron beams from plasmas
talk
Ionization injection can be used to get high quality electron beam in laser wakefield acceleration. To get low energy spread, two injection schemes are proposed here. By use of certain initially unmatched laser pulses, the electron injection can be constrained to the very front region of the mixed gas target, typically in a length of a few hundreds micro meters, and energy spread is largely...
Prof.
Simon Hooker
(University of Oxford)
14/09/2015, 16:50
WG1 - Electron beams from plasmas
talk
We will describe work towards developing a new architecture for plasma accelerators able to generate GeV-scale electron beams at kilohertz repetition rates. Our approach is based on multi-pulse laser wakefield acceleration (MP-LWFA) in which a plasma wakefield is excited by a train of low-energy laser pulses; this approach opens wakefield acceleration to rapidly evolving laser technologies,...
Mr
Andreas Dรถpp
(Laboratoire d'Optique Appliquรฉe / Centro de Lรกseres Pulsados)
14/09/2015, 17:10
WG1 - Electron beams from plasmas
talk
Energy gain in laser wakefield accelerators is generally limited by dephasing between highly relativistic electrons and the driving laser pulse. But as the relative phase depends on both the driver and the cavity length, the effects of dephasing can be mitigated with appropriate tailoring of the plasma density along propagation. The ideal case would provide constant phase adaption, but such a...
118.
Wakefield-Induced Ionization Injection and Self-Similar Staging โจin Beam-driven Plasma Wakes.
Dr
Alberto Martinez de la Ossa
(DESY)
14/09/2015, 18:00
WG1 - Electron beams from plasmas
talk
We propose a simple strategy for controlled ionization-induced trapping of electrons in beam-drivenย plasma accelerators (PWFA) [1]. The presented method exploits the electric wakefields to ionize electrons from aย dopant gas and to capture them into a well-defined volume of the accelerating and focusing wake phase, leading to the formation of high-quality witness bunches. This injection...
Dr
Kevin PEPITONE
(CERN), Dr
Steffen Doebert
(CERN)
14/09/2015, 18:30
WG1 - Electron beams from plasmas
talk
The AWAKE collaboration prepares a proton driven plasma wake field acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10 m long rubidium vapour plasma cell to create strong wake fields allowing sustained electron acceleration. The electron bunch to probe these wake fields get produced by a 20 MeV electron...
Dr
Erik Adli
(University of Oslo, Norway)
14/09/2015, 18:50
WG1 - Electron beams from plasmas
talk
We report on various transverse effects studied experimentally at plasma wakefield experiments at FACET, including betatron motion in a plasma channel, hosing and ion motion. Preliminary results from the FACET 2015 run are included, comparing transverse effects in Hydrogen and Argon plasmas.
Prof.
Roman Walczak
(University of Oxford)
14/09/2015, 19:10
WG1 - Electron beams from plasmas
talk
It has now been shown experimentally that electrons can be accelerated to 4-GeV energies in a plasma wakefield driven by a single high-intensity laser pulse. However, such laser systems have limited repetition rates and low wall-plug efficiency. An alternative method is to resonantly excite plasma oscillations using a train of laser pulses of lower intensity spaced by the plasma period to...
Prof.
Sรฉbastien Corde
(Ecole Polytechnique)
15/09/2015, 15:00
WG1 - Electron beams from plasmas
talk
Beam-driven plasma accelerators, with their high electric fields and energy efficiencies, are being considered as a mean to make future electron-positron colliders more compact and affordable. The field of beam-driven plasma acceleration has recently seen a rapid experimental progress, in particular with the last few years of running of the FACET facility at SLAC.
I will present some of the...
Dr
Guoxing Xia
(Cockcroft Institute and the University of Manchester), Mr
Kieran Hanahoe
(University of Manchester)
15/09/2015, 15:30
WG1 - Electron beams from plasmas
talk
An ultra short, relativistic electron beam with beam energy of 5-250 MeV will be employed to study the key issues in the plasma wakefield acceleration (PWFA) at VELA/CLARA facility at Daresbury laboratory. In this talk, detailed research program on PWFA, e.g. high amplitude wakefield excitation, two-bunch acceleration for VELA/CLARA beam energy doubling, high transformer ratio, long bunch...
Dr
Matthias Gross
(DESY)
15/09/2015, 15:50
WG1 - Electron beams from plasmas
talk
One key aspect of the plasma acceleration experiment which is prepared by the AWAKE collaboration at CERN is the self-modulation of a long (compared to the plasma wavelength) particle beam in a plasma. To study this effect in detail an experiment was conceptualized at the Photo-Injector Test Facility at DESY, Zeuthen site (PITZ) to inject a 6 mm long electron beam into a lithium plasma with a...
Mr
James Cowley
(University of Oxford)
15/09/2015, 16:10
WG1 - Electron beams from plasmas
talk
In multiple-pulse laser wakefield acceleration (MP-LWFA), a train of laser pulses spaced by the plasma period is used to drive a plasma wave, rather than the single pulse used in most experiments. Driving wakefields with a train of low-energy pulses has several advantages: laser-driven plasma accelerators can exploit new laser technologies which cannot deliver high-energy pulses, but which can...
Stefano Romeo
(LNF)
15/09/2015, 16:30
WG1 - Electron beams from plasmas
talk
The purpose of this contribute is the study of the matching conditions of the electron beams inside plasma in the context of the 3 bunch comb scheme experiment in preparation @SPARC_LAB.
We begin by discussing the motivations that led to the choice of the quasi non-linear plasma regime for this experiment.
The study will be carried out through the analysis of some simulations performed with...
Prof.
Victor Malka
(LOA)
15/09/2015, 16:50
WG1 - Electron beams from plasmas
talk
The density profile is a key parameter to optimize the properties of electron beams in laser-plasma accelerators [1,2]. Here we present three different experiments illustrating the use of density tailoring for injecting, increasing the energy or focusing relativistic electron beams. We show that shocks allow to confine injection and hence to reduce significantly the beam energy spread,...
Dr
Olle Lundh
(Lund University)
15/09/2015, 17:10
WG1 - Electron beams from plasmas
talk
Laser wakefield accelerators appear promising as compact sources of highly relativistic electrons and ultrashort pulses of X-rays. However, improving the control of the electron- and X-ray beam parameters is crucially important in order to enable laser wakefield accelerators to be efficiently used in applications. We report on our recent experiments of laser wakefield acceleration and X-ray...
Andrea Renato Rossi
(MI)
15/09/2015, 18:00
WG1 - Electron beams from plasmas
talk
Plasma accelerated beams possess peculiar properties that make them quite different from beams accelerated by conventional means. Rather large energy spreads and divergences (with relativistic transverse momenta) are among such properties. In order to be fruitfully produced and employed, for example for driving cutting edge electromagnetic radiation sources, a careful manipulation is needed,...
Mr
Martin Hansson
(Lund University)
16/09/2015, 16:00
WG1 - Electron beams from plasmas
talk
To improve the stability and reproducibility of laser wakefield accelerators and to allow for future applications, controlling the injection of electrons, both in terms of position of injection and amount of injected charge, is of great importance.
We will present results from our recent experiment on controlled injection, using the scheme of colliding pulses, performed using the Lund...
Gaetano Fiore
(NA)
16/09/2015, 16:30
WG1 - Electron beams from plasmas
talk
We have recently proposed [1-2] a new laser-driven acceleration mechanism based on the violent impact of an ultra-short and ultra-intense laser pulse against the electrons belonging to a superficial thin layer of a low-density plasma (or gas, provided the pulse is sufficiently intense to locally cause its complete ionization). The interplay among the strong ponderomotive effect, the excited...
Dr
Andrey Stepanov
(Insitute of Applied Physics)
16/09/2015, 16:50
WG1 - Electron beams from plasmas
talk
The formation of quasi monoenergetic beams of accelerated electrons by focusing femtosecond laser radiation with an intensity of 2ร1017 W/cm2 onto an edge of aluminium foil has been experimentally demonstrated. The maximum of electrons energy distributions lied in the range from 0.2 to 0.8 MeV with an energy spread less than 20 %. The acceleration mechanism related to the generation of a...
Dr
Fei-Yu Li
(SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom)
16/09/2015, 17:10
WG1 - Electron beams from plasmas
talk
We present a new regime of laser wakefield acceleration from which dense (overcritical density) attosecond (nanometers thick corresponding to attosecond duration) electron sheets (few microns in width determined by the laser focal spot) can be obtained and accelerated. The essential new features are a driving spot greater than the plasma wave length and an upramp-to-plateau density transition...
Dr
Serge Kalmykov
(University of Nebraska - Lincoln)
16/09/2015, 18:00
WG1 - Electron beams from plasmas
talk
Photon engineering [S. Kalmykov et al., New J. Phys. 14, 033025 (2012)] offers new avenues to coherently control electron beam phase space on a femtosecond time scale. It enables generation of high-quality beams at a kHz-scale repetition rate. Reducing the peak pulse power (and thus the average laser power) is the key to effectively exercise such control.
A stepwise negative chirp,...
194.
Multistage laser wakefield acceleration driven by two laser pulses with different focal lengths
Dr
Nobuhiko Nakanii
(Osaka University)
16/09/2015, 18:30
WG1 - Electron beams from plasmas
talk
We are developing high-quality electron source (stable, ultrashort, high charge and narrow energy spread) based on multistage LWFA towards practical applications such as ultrafast electron imaging and x-ray free electron laser. The multistage technique using two laser pulses with different focal lengths enables flexible energy control of the electron beam. In this technique, firstly, tightly...
Alexey Petrenko
(CERN, Budker INP)
16/09/2015, 18:50
WG1 - Electron beams from plasmas
talk
Presently available high-energy proton beams in circular accelerators carry enough momentum to accelerate high-intensity electron and positron beams to the TeV energy scale over several hundred meters of plasma with a density of ~1e15 1/cm^3. However the plasma wavelength at this density is 100-1000 times shorter than the typical longitudinal size of the high-energy proton beam. Therefore the...
Prof.
Vladimir Litvinenko
(Stony Brook University)
16/09/2015, 19:10
WG1 - Electron beams from plasmas
talk
The project will explore a large (e.g. psec or 0.5 mm) length of โbubbleโ in CO2-laser driven plasma wake-field accelerator. Injecting of an external high quality electron bunch with duration ~ 10 fsec synchronized with the โbubbleโ would allow us to accelerate high quality electron beams with energy stability and spread reaching towards 1E-4. We rely on CO2-laser power upgrades that are in...
Dr
Sven Steinke
(Lawrence Berkeley National Laboratory)
17/09/2015, 16:00
WG1 - Electron beams from plasmas
talk
We present results of a probing experiment where two Laser-Plasma-Accelerator stages are coupled at a short distance by a plasma mirror. Stable electron beams were focused by a discharge capillary-based active plasma lens to a micrometer spot size in a H2 plasma, such that they interact with a dark-current-free, quasi-linear wakefield excited by the laser of the second stage. Changing the...
Prof.
Danilo Giulietti
(PI)
17/09/2015, 16:30
WG1 - Electron beams from plasmas
talk
Since the beginning of the high power pulsed laser era, the energy of particles, emerging from plasmas generated in laser matter-interaction, was found sensibly higher than that expected on the basis of the plasma estimated temperature.The evolution in the laser pulse amplification techniques and the progressive shortening of the pulse duration was accompanied by a corresponding increase in...
Olena Kononenko
(Deutsches-Elektronen-Synchrotron (DESY))
17/09/2015, 16:50
WG1 - Electron beams from plasmas
talk
Plasma wakefields can support very high field gradients (~ 100 GV/m)
which makes particle acceleration to ultra-relativistic energies possible
within a few millimeters. Precise control over the electron bunch phasespace
during the process of injection into the accelerating wakefield is
needed for the production of high-quality electron beams. Shaping of the
longitudinal plasma-density...
Dr
Carl Schroeder
(Lawrence Berkeley National Laboratory)
17/09/2015, 17:10
WG1 - Electron beams from plasmas
talk
Ionization injection has become a commonly used technique to trap electrons in plasma wakefields. Ionization injection, where electrons are ionized by an intense laser in the plasma wakefield, reduces the wakefield amplitude required for trapping. The lower trapping threshold allows operation at lower plasma densities, enabling higher beam energy gains. However, ionization injection can also...
Mr
Benoit Beaurepaire
(Laboratoire d'Optique Appliquรฉe (LOA))
17/09/2015, 18:00
WG1 - Electron beams from plasmas
talk
Recently, several groups have been developing laser-plasma accelerators operating at high repetition rate, using kHz lasers with energies < 10 mJ [1, 2]. Such developments are particularly important for applications as the high repetition rate improves the beam stability and permits data accumulation [3].
We performed an experiment of electrons acceleration by tightly focusing kHz, few-mJ...
Mr
Alexander Knetsch
(University of Hamburg)
17/09/2015, 18:30
WG1 - Electron beams from plasmas
talk
The underdense photocathode "Trojan Horse" plasma wakefield acceleration is a promising technique for the generation of high-brightness and low-emittance witness bunches.
It is shown that requirements on the driver electron beam can be substantially
decreased by performing the witness beam generation on a soft density downramp, which facilitates trapping.
As a consequence the underdense...
Dr
Fatema Tanjia
(Universitร di Napoli Federico II and INFN Sezione di Napoli)
17/09/2015, 18:50
WG1 - Electron beams from plasmas
talk
A numerical investigation on the spatiotemporal evolution of an electron beam, externally injected in a plasma in the presence of a plasma wake field is carried out. The latter is driven by an ultra-short relativistic axially-symmetric femtosecond electron bunch. We first derive a novel Poisson-like equation for the wake potential where the driving term is the ultra-short bunch density, taking...
