FEL2014 - List of Authors (Bourassin-Bouchet, C.)

Paper	Title	Page
TUP002	Characterization of Partially Coherent Ultrashort FEL Pulses	346
	C. Bourassin-Bouchet, M.-E. Couprie SOLEIL, Gif-sur-Yvette, France C. Evain PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
	Temporal metrology is a major need for free-electron lasers. However, the lack of longitudinal coherence, that is shot-to-shot fluctuations, of these sources has prevented so far the full amplitude and phase temporal characterization of FEL pulses. To sort out this issue, we propose a solution inspired from attosecond metrology, where XUV pulse measurement techniques already exist, and from coherent diffraction imaging, where numerical solutions have been developed for processing partially coherent diffraction patterns. The experimental protocole implies the measurement of photoelectron spectra obtained through XUV-laser photoionisation. The spectra are then processed with an algorithm in order to retrieve the partially coherent FEL pulse. When applied to SASE FELs, the technique gives access to the full statistics of the emitted pulses. With seeded-FELs, the pulse shape becomes stable from shot-to-shot, but an XUV-laser time jitter remains. In that case, the technique enables the joint measurement of the FEL pulse shape (in amplitude and phase) and of the laser/FEL jitter envelope. The concept has been validated with numerical simulations in the context of the LUNEX5 FEL project.

TUP086	Experiment Preparation Towards a Demonstration of Laser Plasma Based Free Electron Laser Amplification	569
	M.-E. Couprie, C. Benabderrahmane, P. Berteaud, C. Bourassin-Bouchet, F. Bouvet, F. Briquez, L. Cassinari, L. Chapuis, M.E. El Ajjouri, C. Herbeaux, N. Hubert, M. Labat, A. Lestrade, A. Loulergue, J. Lüning, O. Marcouillé, J.L. Marlats, F. Marteau, C. Miron, P. Morin, F. Polack, K. Tavakoli, M. Valléau, D. Zerbib SOLEIL, Gif-sur-Yvette, France I.A. Andriyash, G. Lambert, V. Malka, C. Thaury LOA, Palaiseau, France S. Bielawski, C. Evain, C. Szwaj PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France X. Davoine CEA/DAM/DIF, Arpajon, France
	One direction towards compact Free Electron Laser is to replace the conventional linac by a laser plasma driven beam, provided proper electron beam manipulation to handle the value of the energy spread and of the divergence. Applying seeding techniques also enables to reduce the required undulator length. Rapidly developing Laser Wakefield Accelerators (LWFA) are already able to generate synchrotron radiation. With the presently achieved electron divergence and energy spread an adequate beam manipulation through the transport to the undulator is needed for FEL amplification. A test experiment for the demonstration of FEL amplification with a LWFA is under preparation in the frame of the COXINEL ERC contract in the more general context of LUNEX5. Electron beam transport follows different steps with strong focusing thanks to variable strength permanent magnet quadrupoles, demixing chicane with conventional dipoles, and a second set of quadrupoles for further focusing in the undulator. Progress on the equipment preparation and expected performance are described.

TUP087	The Status of LUNEX5 Project	574
	M.-E. Couprie, C. Benabderrahmane, P. Berteaud, C. Bourassin-Bouchet, F. Bouvet, F. Briquez, L. Cassinari, L. Chapuis, J. Daillant, M. Diop, M.E. El Ajjouri, C. Herbeaux, N. Hubert, M. Labat, P. Lebasque, A. Lestrade, A. Loulergue, P. Marchand, O. Marcouillé, J.L. Marlats, C. Miron, P. Morin, A. Nadji, F. Polack, F. Ribeiro, J.P. Ricaud, P. Roy, K. Tavakoli, M. Valléau, D. Zerbib SOLEIL, Gif-sur-Yvette, France S. Bielawski PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France B. Carré, D. Garzella CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France X. Davoine CEA/DAM/DIF, Arpajon, France N. Delerue LAL, Orsay, France G. Devanz, A. Mosnier CEA/DSM/IRFU, France A. Dubois, J. Lüning CCPMR, Paris, France C. Evain, E. Roussel, C. Szwaj PhLAM/CERLA, Villeneuve d'Ascq, France G. Lambert, R. Lehé, V. Malka, A. Rousse, C. Thaury LOA, Palaiseau, France C. Madec CEA/IRFU, Gif-sur-Yvette, France
	LUNEX5 (free electron Laser Using a New accelerator for the Exploitation of X-ray radiation of 5th generation) aims at investigating the production of short, intense, coherent Free Electron Laser (FEL) pulses in the 40-4 nm spectral range. It comprises a 400 MeV superconducting Linear Accelerator for high repetition rate operation (10 kHz), multi-FEL lines and adapted for studies of advanced FEL schemes, a 0.4 - 1 GeV Laser Wake Field Accelerator (LWFA) for its qualification by a FEL application, a single undulator line enabling seeding with High order Harmonic in Gas and echo configurations and pilot user applications. Concerning the superconducting linac, the electron beam dynamics has been modified from a scheme using a third harmonic linearizer and a compression chicane to dog-leg coupled to sextupoles. Besides, the choice of the gun is under revision for fulfilling to 10 kHz repetition rate. Following transport theoretical studies of longitudinal and transverse manipulation of a LWFA electron beam enabling to provide theoretical amplification, a test experiment is under preparation in collaboration with the Laboratoire d’Optique Appliquée towards an experimental demonstration.

THP087	Electron Beam Diagnostics for COXINEL	937
	M. Labat, C. Bourassin-Bouchet, L. Cassinari, M.-E. Couprie, M.E. El Ajjouri, N. Hubert, A. Loulergue SOLEIL, Gif-sur-Yvette, France
	On the path towards more compact free electron lasers (FELs), the project COXINEL was recently funded: a transfer line will be installed to adapt a plasma accelerated beam (from LOA) into an in-vacuum undulator built by SOLEIL. This experiment should enable to demonstrate the first FEL based on a plasma accelerator. Because plasma beams are intrinsically very different from RF acceletor beams (much shorter, divergent and smaller with a higher energy spread and energy jitter), their transport and matching in the undulator is critical if willing to obtain a significant amplification. This is why special care has to be taken in the design of the beam diagnostics to be able to measure the transverse beam sizes, energy spread and jitter, emittance and bunch length. For these purposes, several diagnostics will be implemented from the plasma accelerator exit down to the undulator exit. In each station, several screen types will be available and associated to high resolution imaging screens. In this paper, we present the experimental layout and associated simulation of the diagnostics performances.

Paper

Title

Page

Characterization of Partially Coherent Ultrashort FEL Pulses

346

C. Bourassin-Bouchet, M.-E. Couprie
SOLEIL, Gif-sur-Yvette, France
C. Evain
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France

Temporal metrology is a major need for free-electron lasers. However, the lack of longitudinal coherence, that is shot-to-shot fluctuations, of these sources has prevented so far the full amplitude and phase temporal characterization of FEL pulses. To sort out this issue, we propose a solution inspired from attosecond metrology, where XUV pulse measurement techniques already exist, and from coherent diffraction imaging, where numerical solutions have been developed for processing partially coherent diffraction patterns. The experimental protocole implies the measurement of photoelectron spectra obtained through XUV-laser photoionisation. The spectra are then processed with an algorithm in order to retrieve the partially coherent FEL pulse. When applied to SASE FELs, the technique gives access to the full statistics of the emitted pulses. With seeded-FELs, the pulse shape becomes stable from shot-to-shot, but an XUV-laser time jitter remains. In that case, the technique enables the joint measurement of the FEL pulse shape (in amplitude and phase) and of the laser/FEL jitter envelope. The concept has been validated with numerical simulations in the context of the LUNEX5 FEL project.

TUP086

Experiment Preparation Towards a Demonstration of Laser Plasma Based Free Electron Laser Amplification

569

M.-E. Couprie, C. Benabderrahmane, P. Berteaud, C. Bourassin-Bouchet, F. Bouvet, F. Briquez, L. Cassinari, L. Chapuis, M.E. El Ajjouri, C. Herbeaux, N. Hubert, M. Labat, A. Lestrade, A. Loulergue, J. Lüning, O. Marcouillé, J.L. Marlats, F. Marteau, C. Miron, P. Morin, F. Polack, K. Tavakoli, M. Valléau, D. Zerbib
SOLEIL, Gif-sur-Yvette, France
I.A. Andriyash, G. Lambert, V. Malka, C. Thaury
LOA, Palaiseau, France
S. Bielawski, C. Evain, C. Szwaj
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
X. Davoine
CEA/DAM/DIF, Arpajon, France

One direction towards compact Free Electron Laser is to replace the conventional linac by a laser plasma driven beam, provided proper electron beam manipulation to handle the value of the energy spread and of the divergence. Applying seeding techniques also enables to reduce the required undulator length. Rapidly developing Laser Wakefield Accelerators (LWFA) are already able to generate synchrotron radiation. With the presently achieved electron divergence and energy spread an adequate beam manipulation through the transport to the undulator is needed for FEL amplification. A test experiment for the demonstration of FEL amplification with a LWFA is under preparation in the frame of the COXINEL ERC contract in the more general context of LUNEX5. Electron beam transport follows different steps with strong focusing thanks to variable strength permanent magnet quadrupoles, demixing chicane with conventional dipoles, and a second set of quadrupoles for further focusing in the undulator. Progress on the equipment preparation and expected performance are described.

TUP087

The Status of LUNEX5 Project

574

M.-E. Couprie, C. Benabderrahmane, P. Berteaud, C. Bourassin-Bouchet, F. Bouvet, F. Briquez, L. Cassinari, L. Chapuis, J. Daillant, M. Diop, M.E. El Ajjouri, C. Herbeaux, N. Hubert, M. Labat, P. Lebasque, A. Lestrade, A. Loulergue, P. Marchand, O. Marcouillé, J.L. Marlats, C. Miron, P. Morin, A. Nadji, F. Polack, F. Ribeiro, J.P. Ricaud, P. Roy, K. Tavakoli, M. Valléau, D. Zerbib
SOLEIL, Gif-sur-Yvette, France
S. Bielawski
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
B. Carré, D. Garzella
CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
X. Davoine
CEA/DAM/DIF, Arpajon, France
N. Delerue
LAL, Orsay, France
G. Devanz, A. Mosnier
CEA/DSM/IRFU, France
A. Dubois, J. Lüning
CCPMR, Paris, France
C. Evain, E. Roussel, C. Szwaj
PhLAM/CERLA, Villeneuve d'Ascq, France
G. Lambert, R. Lehé, V. Malka, A. Rousse, C. Thaury
LOA, Palaiseau, France
C. Madec
CEA/IRFU, Gif-sur-Yvette, France

LUNEX5 (free electron Laser Using a New accelerator for the Exploitation of X-ray radiation of 5th generation) aims at investigating the production of short, intense, coherent Free Electron Laser (FEL) pulses in the 40-4 nm spectral range. It comprises a 400 MeV superconducting Linear Accelerator for high repetition rate operation (10 kHz), multi-FEL lines and adapted for studies of advanced FEL schemes, a 0.4 - 1 GeV Laser Wake Field Accelerator (LWFA) for its qualification by a FEL application, a single undulator line enabling seeding with High order Harmonic in Gas and echo configurations and pilot user applications. Concerning the superconducting linac, the electron beam dynamics has been modified from a scheme using a third harmonic linearizer and a compression chicane to dog-leg coupled to sextupoles. Besides, the choice of the gun is under revision for fulfilling to 10 kHz repetition rate. Following transport theoretical studies of longitudinal and transverse manipulation of a LWFA electron beam enabling to provide theoretical amplification, a test experiment is under preparation in collaboration with the Laboratoire d’Optique Appliquée towards an experimental demonstration.

THP087

Electron Beam Diagnostics for COXINEL

937

M. Labat, C. Bourassin-Bouchet, L. Cassinari, M.-E. Couprie, M.E. El Ajjouri, N. Hubert, A. Loulergue
SOLEIL, Gif-sur-Yvette, France

On the path towards more compact free electron lasers (FELs), the project COXINEL was recently funded: a transfer line will be installed to adapt a plasma accelerated beam (from LOA) into an in-vacuum undulator built by SOLEIL. This experiment should enable to demonstrate the first FEL based on a plasma accelerator. Because plasma beams are intrinsically very different from RF acceletor beams (much shorter, divergent and smaller with a higher energy spread and energy jitter), their transport and matching in the undulator is critical if willing to obtain a significant amplification. This is why special care has to be taken in the design of the beam diagnostics to be able to measure the transverse beam sizes, energy spread and jitter, emittance and bunch length. For these purposes, several diagnostics will be implemented from the plasma accelerator exit down to the undulator exit. In each station, several screen types will be available and associated to high resolution imaging screens. In this paper, we present the experimental layout and associated simulation of the diagnostics performances.