Cros, B

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EU contract number RII3-CT-2003-506395 CARE/ELAN Document-2007-023            Overview of the EuroLEAP project B. Cros1 1) CNRS- LPGP, Orsay, France    Abstract  The European Laser Electron controlled Acceleration in Plasmas to GeV energy range (EuroLEAP, www.euroleap.eu) project is funded by the EU for 3 years (2006-2009) and involves 11 groups in France (CNRS: LPGP - B. Cros, LOA - V. Malka, LLR - H. Videau, LAL - R. Roux), the UK (U. of Strathclyde - D. Jaroszynski, Imperial College – Z. Najmudin, U. of Oxford – S. Hooker, CLF RAL – M. Dunne), the Netherlands (U. of Eindhoven – M. van der Wiel, U. of Twente – F. van Goor) and Portugal (IST – L. Silva). An overview of this project was presented at the Laser Plasma acceleration meeting held in the Azores in July 07.     - 1 - EU contract number RII3-CT-2003-506395 CARE/ELAN Document-2007-023 Introduction The main objective of the EuroLEAP project is the achievement of a laser-plasma accelerator to test the issues related to the control of the properties of an electron beam accelerated to the GeV range in a plasma wave. Short pulse electron beams, produced by laser injectors in a plasma or by RF photo-injectors, will be injected and accelerated in a plasma wave created inside wave guides over a few centimetres. Different techniques to produce short bunches of electrons will be tested and compared, as well as different techniques for laser guiding and creating the accelerating plasma wave. Specific diagnostics will be developed to characterise the produced electron bunches. Simulation will support the joint experimental efforts. Recently commissioned facilities at the U. of Strathclyde and at the CLF-RAL will provide unique opportunities to benchmark optical injection and RF photo-injection techniques. The goal is to produce electron bunches in the GeV range, with an energy spread close to 1% in a reproducible way over a distance less than 10 cm.  Acknowledgements We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 “Structuring the European Research Area” programme (CARE, contract number RII3-CT-2003-506395)  - 2 - 1European Laser Electron controlled Acceleration  in Plasmas  to GeV energy rangeProject: NEST ADVENTURE STREP Coordination: Brigitte CROS (CNRS- LPGP)Sept. 2006 -2009 LPAW07, B Cros July 2007 2ObjectivesTo build a laser-plasma acceleratorTo accelerate electrons to the GeV energy range in a plasma wave.To test the issues related to the control of the properties of the electron beamExpected result: accelerated e-beam with – energy in the GeV range, – energy spread of the order of 1%, – pulse duration of the order of 100 fs, – charge in the range 10 pC to 100 pC.2LPAW07, B Cros July 2007 3ParticipantsFrance . Centre National de la Recherche Scientifique  (CNRS) : LPGP, LOA, LLR, LALUK . STFC- CLF RAL, U STRATHCLYDE, Imperial College,  U OXFORDThe Netherlands. U. Twente (UT),  Eindhoven U. of Technology (TUE)Portugal. Instituto Superior Técnico(IST-GOLP)LPAW07, B Cros July 2007 4ResourcesAccelerator laboratories and laser facilitiesTUE, UT, LALRAL, LOA, USTRAT, ISTWaveguide development labsOXFORD, IST, LPGPDiagnostics development labsLLR, USTRAT, TUE, UTModeling and simulation infrastructuresEuropean funds:  2M Euros are forPost-doc or PhDConsumables, transfer of equipment, missions for collaborative experiments, collaboration meetings, management3LPAW07, B Cros July 2007 5Research activitiesWP1: Laser Injector Development WP2: RF Photo-Injector Development WP3: Production of a plasma wave over a long distance WP4: Injection & Controlled Acceleration  WP5: DiagnosticsLPAW07, B Cros July 2007 6WP1: Laser Injector DevelopmentDemonstrate all-optical injection (AOI) and acceleration of ultra-short (10 fs) electron bunches by – colliding laser pulses (CDP) – collinear pulses (CLP)Characterize and optimize the spectrum of electrons Achieve mono-energetic, low emittanceelectron beams at a few tens of MeV to 200 MeV4LPAW07, B Cros July 2007 7Colliding laser pulses - LOASimulation, A. LifshitzD. Umstadter et al, PRL 76, 2073 (1996); E. Esarey et al, PRL 79, 2682 (1997)The ponderomotive force associated to the beating of the two laser pulses accelerates plasma electrons up to trapping thresholdFaure et al., nature, dec 2006LPAW07, B Cros July 2007 8WP2: RF Photo-InjectorDevelopmentImprove existing technology in order to build RFPIs to produce e- bunches with: – 50 to 100 pC charge, – 50 fs to 1ps duration, – energy 3- 4 MeV, energy spread 2%Transport and focus the electron beam at the entrance of the plasmaCommission RFPIs for acceleration experiment5LPAW07, B Cros July 2007 9RF Photo-InjectorsPhoto-injecteur build by LAL and implemented at U. ofStrathclydeInjection scheme at TUE. Electrons produced by thePI (left) are accelerated by the RF cavity, thenfocussed at the entrance of the plasma.-100-500 50 100GPT x [µm]-100-50050100y [µm]y [µm]LPAW07, B Cros July 2007 10Longitudinal compression sectionTwo subsequent 45-degree bending magnets and a compensation quadrupolemagnet between the bending magnets introduce an energy-dependent path length to compress the bunch.Focusing and compression sectionsSub-picosecond beam Compressor at U. TwenteCompression: 2ps --? 250 fs, 2.88 MeV6LPAW07, B Cros July 2007 11WP3: Production of a plasma waveover a long distanceDevelop plasma media allowing to achieve a plasma wave over several centimetresStudy the propagation of intense laser pulses (≥1017W.cm-2) in the waveguidesControl the plasma wave stability, repeatability and lifetimeAchieve a product of gradient and length of 1 GVLPAW07, B Cros July 2007 12High intensity laser GuidingComparison of guiding by a plasma channeland by reflection from the tube wallsIt is necessary to improve the laser beamquality in order to achieve monomode guidingTube LPGP L= 5cm, r = 50 µm, filled with H2, I = 5 1017 W/cm2A. Gonsalves et al., PRL 98, 025002 (2007)Plasma channel,  U. Oxford7LPAW07, B Cros July 2007 13Plasma waves diagnostics -LPGPAIHT of RASCapillary: D = 100 mm, L = 6 cm, εw = 2.25, filled with hydrogenPump pulse: λ = 0.8 mm,  τFWHM= 35 fs, IL= 5.×1017 W/cm2, P=8.5 TWProbe pulse:  λ= 0.4 mm, τFWHM= 490 fs, Tdelay=760 fs, spectral width 5 nm0 20 40 60 80 100-0.2-0.10.00.10.20.30.40.5Amp(r=0, ξ)ξ = kp(z-ct) |apump| δn / n0 δΦ1500 1250 1000 750 500 250 0-0.0050.0000.0050.0100.015 t [fs]|aprobe| |aprobe|z = 00 20 40 60 80 100-0.2-0.10.00.10.20.30.40.5Amp(r=0, ξ)ξ = kp(z-ct) |apump| δn / n0 δΦ1500 1250 1000 750 500 250 0-0.0050.0000.0050.0100.0150.0200.025 t [fs]|aprobe| |aprobe|z = 3 cm0 10 20 30 40 50 60-3,0-2,5-2,0-1,5-1,0-0,50,0Δω / ωpz [mm] analytical modelingpump: red frequency shift385 390 395 400 405 410 4150.00.20.40.60.81.00.00.20.40.60.81.0I(λ)λ [nm]probe: z = 0 z = 6 cm LPAW07, B Cros July 2007 14WP4: Injection & Controlled AccelerationInject and accelerate electrons in a linear plasma wave over a long distance (several centimetres)Achieve a precise theoretical modelling and control the different elements of the acceleration process Build a prototype to achieve accelerated electron beams with – energy in the GeV range, – energy spread of the order of 1%, – pulse duration of the order of 100 fs, – charge in the range 10 pC to 100 pC.8LPAW07, B Cros July 2007 15Snapshots of an electron bunch during trapping, compression and acceleration in the laser wakefieldat several distances in the plasma channel. The ellipse depicts the position of the laser pulse.From: NIM A 566 p.244 (2006).0 cm 1 cm2.5 cm 5 cmInjection of electrons in front of the laser pulse – U. TwenteLPAW07, B Cros July 2007 169LPAW07, B Cros July 2007 17Scheme at U. StrathclydeLaser : 1J, 50 fsLPAW07, B Cros July 2007 18WP5: DiagnosticsDevelopmentDevelop and implement diagnostics to characterizebeam profile, charge, energy, time duration10LPAW07, B Cros July 2007 19Plans up to Feb ‘08Commissioning of diagnostics– charge measurement (ICT, scintillating screens) and electron– spectrometerGeneration of visible/UV radiation pulses in undulator– radiation spectrum provides information on electron bunch– energy spectrum and emittance (also charge if no electrons are lost)Installation of Coherent Transition Radiation (CTR) detection system– diagnostic of electron bunch charge, shape and duration Design & Construction of Pepper Pot emittance diagnosticLLR imaging spectrometer– high energy, high resolutionLPAW07, B Cros July 2007 20Conclusion and perspectiveThe EuroLEAP partners are developping a project to control the properties of the electrons beams produced in a laser plasma accelerator,which is a necessary step to developapplications and the increase of energy through stagingCompact controllable e-source in the GeV rangeDissemination to University size labs Industrial spin-offs (laser, photo-injector technology, synchronisation)Applications to femtosecond X-ray generation,femtochemistry, radiobiology, …First stage of a laser plasma acceleratorWill allow to evaluate the feasibility of building a multi-stages accelerator for high energyBasis for a larger scale project at the European level.11LPAW07, B Cros July 2007 21Web site www.euroleap.eu

Overview of the EuroLEAP project

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