Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Accelerator R&D in the frame of the CILEX project in France Brigitte CROS LPGP-CNRS-Université Paris Sud 1

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Contributions 2 A. Specka 1, B. Cros 2, P. Monot 3, T. Audet 2, A. Beck 1, M. Bougeard 3, C. Bruni 4, A-M. Cauchois 1, A. Chancé 5, N. Delerue 4, O. Delferrière 5, F. Desforges 2, S. Dobosz Dufrénoy 3, M. Grech 6, P. Lee 2, A. Maitrallain 3, J.R. Marquès 6, Ph. Martin 3, G. Maynard 2, A. Mosnier 5, P. Mora 7, B. S. Paradkar 2, J. Schwindling 5, K. Ta Phuoc 8, T. Vinatier 4, P. Audebert 6, F. Amiranoff 6 1 LLR, Ecole Polytechnique, CNRS, Palaiseau France 2 LPGP, CNRS, Université Paris Sud, Orsay, France 3 LIDyL, CEA, IRAMIS, Centre de Saclay, France. 4 LAL, CNRS, Université Paris Sud, Orsay, France 5 SACM, CEA, IRFU, Centre de Saclay, France. 6 LULI, Ecole Polytechnique, CNRS, CEA, UPMC, Palaiseau, France 7 CPhT, Ecole-Polytechnique, CNRS, Palaiseau, France. 8 LOA, ENSTA, Ecole-Polytechnique, CNRS, Palaiseau, France.

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Outline Overview of the CILEX project Multi-stage LPA studies: objectives and organisation of work Ongoing work : injector, beam transport, accelerator Summary 3

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Centre Interdisciplinaire Lumière EXtrême 4 CEA - Saclay Université Paris Sud Soleil Orme des merisiers 1km Ecole Polytechnique Ecole Polytechnique ENSTA Institut d'Optique Research Centre on Intense Lasers, Plasmas and Applications

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015  Multi-PW laser APOLLON 10PW  Multi-beam facility 1 PW + probe + ns  Dedicated experimental areas  Satellite facilities UHI100  Multi-disciplinary program  Training of scientists and engineers  Operated as a user-facility Implementation at l’Orme des merisiers

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 long focal-length area short focal-length area Apollon laser Hall Layout of the Apollon facility 6 6  Highest intensity  Solid targets  Ion acceleration  Radiation generation  Highest intensity  Solid targets  Ion acceleration  Radiation generation  High intensity  Gas targets, large volume  Electron acceleration  Radiation generation  Electron/photon interaction  High intensity  Gas targets, large volume  Electron acceleration  Radiation generation  Electron/photon interaction

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April Apollon Laser beams will be distributed in target areas 7 Energy can be varied step by step Synchronisation (master beam and delay lines) Repetition rate: 1 shot/min 10PW: 15fs – A few ps, 150J, 75J, 50J, 25J ns beam: 200J, uncompressed 1PW: 15fs – A few ps, 15J, 10J, 5J, 1J probe beam: <20fs, 0.25 J

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Operation as a user facility 8 Apollon facility will be opened to national and international users Beam time allocation per year – 30 weeks for users – 10 weeks maintenance – 10 weeks development Beam delivery to experimental areas – Each experimental area will receive the beam for scheduled periods of time – Laser pulse sequences will be delivered at the request of users, 6 hours per day – Tentatively, 2 days will be allocated for changing the laser beam configuration between experimental areas

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Motivation for Laser Plasma Acceleration in the frame of CILEX Study the feasibility of a laser plasma accelerator scalable to high particle energy – > High gradient technology and meter scale stages Implement a test facility for laser plasma acceleration studies: build a community of physicists Develop a reliable relativistic electron source for applications: build a community of users 9 B. Cros et al, NIMA (2014 )

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Work is planned in 3 phases PHASE 1: Design experiments in Long Focal-length Area (LFA)  Research program on other facilities  Conceptual & technical design of the experimental set-up  Procurement & implementation of equipment in LFA PHASE 2: Commissioning of the 1 st PW beam and facility through the mechanism of LPA in the bubble regime  Validation of laser specification (I < W/cm 2, a 0 < 7)  Comparison to scaling laws and exploratory experiments  Injector optimization PHASE 3: Develop a two stage Laser Plasma Accelerator (Injector/accelerator) Electron beam transport, focusing, synchronisation, and injection into a plasma wave over a long distance 10

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015  First stage (bubble regime operation) provides high gain.  Second stage (linear/moderately non-linear operation) provides control and stability.  Scalability : Energy gain while maintaining beam properties  Experimentally challenging : each component requires state- of-the-art equipment and know-how Multistage LWFA to achieve stable tuneable electron source 11 Bubble regime operation inside a short gas cell First stage Laser Laser for second stage Moderately non-linear regime operation inside a long dielectric capillary tube

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Design of two stage LPA in the long focal length area of Apollon facility 12 1 PW (15 J, 15 fs) laser: first stage driver 10 PW (150 J, 15 fs) laser: second stage driver

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Components are developped separately to prepare implementation in the Long Focal-length area of Apollon facility 13

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April st Stage (ELISA): ELectron Injector for compact Staged high energy Accelerator 14 Develop a reliable electron source Optimize electron production from a gas cell with variable length, filled with hydrogen gas and electron dopant Principle of Ionization injection: Ionization and trapping of e- by tunneling photo-ionization of high Z atom (eg nitrogen) at the peak of laser intensity Pak et al. Phys. Rev. Lett. 104, (2010)

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Promising results obtained with ELISA at UHI100 facility 15 1st Stage (ELISA): – Ionization injection scheme – Simulations with WARP PIC code – Experiments in gas cell at UHI100 facility (CEA Saclay) and LLC facility (Lund) Electron spectra: Simulation Experiment F.G. Desforges et al, Phys. Plasmas (2014 )

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Beamline designed to test transport of electron beam at UHI100 facility 16 Simulations with Tracewin and WARP for a reference energy of 50MeV Transverse and longitudinal phase-space density at focus Design and implementation of beam transport and characterization is underway using expected e-parameters Compact design to fit in the vacuum chamber at UHI100 Triplet of quads and dipole for energy measurement with 0.5% resolution A. Chancé et al, NIMA (2014 )

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015  Multi-GeV acceleration of electrons inside a dielectric capillary over the damping length Second stage is modeled with the reduced PIC code WAKE_EP 17 W 0 =100µm W 0 =150µm W 0 =240µm Energy (GeV) a 0 =1.4; 40 fs (30J, 65J, 165J) Capillary radius 154µm, electron density cm -3, plasma wavelength 100µm e- injection (10pC, 10fs, 10µm, 50MeV) B. S. Paradkar et al, Phys. Plasmas (2013 )

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Diagnostics development is underway Laser: focal spot, energy, spectrum, before / after interaction. 3 electron energy spectrometers: – MeV range for the injector, – broad energy range, up to 1GeV, for the non linear regime, – up to 10 GeV for the second stage. Electron bunch: pointing detectors, pulse duration, charge. X-ray diagnostics (betatron) to characterize electron acceleration 18 G. Genoud et al, App Phys B 105, 309 (2011 ) J. Ju et al Phys Rev STAB (2014)

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Summary A unique opportunity on the Plateau de Saclay for LPA: – Apollon laser will deliver two beams at the 1 to 10 PW level, with short pulse duration, in a large area of shielded rooms at l’Orme des Merisiers – LPA and radiation generation studies will be possible in a versatile environnement The multistage laser plasma acceleration programme at CILEX addresses the main challenges of laser plasma accelerators Apollon facility will operate as an electron acceleration test facility opened to collaborators and users 19

Brigitte Cros, 2nd Eucard-2 meeting, Barcelona, April 2015 Aknowledgements 20 Laboratoire Charles Fabry