Laser-Plasma Acceleration in Sweden Electrons Protons X-rays Claes-Göran Wahlström Department of Physics, Lund University and Lund Laser Centre

Lund - an old city with a large university

Lund - A city with a strong accelerator future LWFA 3.5 GeV e GeV p+ 2020

Ion source 2.5 GeV Proton Accelerator Klystrons Spallation Target station Neutron Instruments European Spallation Source - ESS Goal: Neutrons in Lund before 2020 Investment: 1.5 B€ / ~10y Operations:10 M€ / y

-390 m length -2.9 ms pulses -2.5 GeV proton energy -14 Hz -5 MW average beam power ESS 2.5 GeV proton LINAC Ongoing international R&D Mats Lindroos – Project leader

Electron source 3.5 GeV Linear accelerator (ca 250 m) MAX IV with its 3.5 GeV LINAC Short Pulse Facility FEL expansion 3 GHz normal conducting 100 Hz rep rate RF photo cathode gun 2 bunch compressors 3 Operation modes: Ring injection / SPF /FEL Emittance (norm): mm mRad (FEL/SPF-mode) Charge: pC (FEL/SPF-mode) Bunch length: 100 fs 3 GeV Ring (528 m circ.)

Established at Lund University in 1995 Atomic Physics Combustion Physics Laboratory Astrophysics Chemical Physics LU Medical Laser Centre Laser research at MAX-lab ~110 Scientists, incl. 14 Professors, 65 PhD. Students European Large Scale Infrastructure since 1996 Lund High-Power Laser Facility

LASERLAB-EUROPE The Integrated Initiative of European Laser Laboratories Lund Laser Centre – a partner in Laserlab-Europe The LLC provides Access to External Users

The Lund Multi-Terawatt Laser 10 Hz, 800 nm, 35 fs, 40 TW

The Ultra-High Intensity Laser Physics Group Matthias BurzaGuillaume GenoudFranck Wojda Anders Persson Kristoffer Svensson Olle LundhLovisa SenjeMartin Hansson C-G W ~6% of LLC

Stuart Mangles, A. Thomas, S. Kneip, Z. Najmudin, K. Krushelnick, N. Dover, M. Bloom, M. Kaluza, C. Kamperidis et al.. Plasma Physics Group Imperial College, London, UK Brigitte Cros, K. Cassou, F. Wojda, Jinchuan JU, et al. Laboratoire de Physique des Gaz et des Plasmas (LPGP), Université Paris Sud 11, Orsay, France With the support of MaxLas, EuroLEAP and Laserlab Europe Key Collaborators for Electron Acceleration

35 fs, 680 mJ Laser pulses f/10 focusing LWFA with IC London

LWFA of Monoenergetic Electron Beams in the First Plasma Wave Period Mangles et al. PRL 96, (2006). Electron Beam Profile Electron Beam Profile (E > 7 MeV) elliptical Axis of ellipse along direction of laser polarization Electron motion in E-field of the laser increases beam divergence in direction of polarization – Electrons and laser overlap spatially Laser polarization Electron beam profile Beam profile tilt  º Laser polarization  º

r = 10 7 r = 10 6 Electron beam stability - contrast ratio Plasma Physics and Controlled Fusion 48, B83 (2006).

Effect of Coma on the electron beam flat wavefront: – e-spectrum well collimated and no variation of beam position with energy λ coma: – Beam divergence is increased – e-beam exhibits variation of beam position with energy, amplitude ~ 20 mrad Profile Electron spectrum Flat wavefront0.175 λ coma

Effect of Coma on the X-ray spectrum increasing the amplitude of coma aberration clearly increases the critical energy of the X-ray spectrum → increase oscillation amplitude from r β = 1 ± 0.4 μm to 3 ± 1 μm Mangles et al., Applied Physics Letters 95, (2009).

Effect of Spherical Aberration on the Wavebreaking Threshold Submitted (2011)

Material: Glass Length: 10 to 100 mm Inner diam: μm Filled with H 2 Excellent matched guiding over several cm possible Technical challenge: very sensitive to laser pointing and spot quality L Hollow Dielectric Waveguide Capillaries With LPGP Orsay, Brigitte Cros et al. F. Wojda et al., Phys. Rev. E 80, (2009).

Implementing Adaptive Optics in the Compressed Beam Before After

Labview FPGA Active Pointing Stabilization G. Genoud et al. Rev. Sci. Instr. 82, (2011) Piezo mirror2D Photo-sensitive detector Target FIR digital filter Reference beam Fast shutter

laser pulse, 40 fs, 700 mJ CCD camera and objective X-ray sensitive CCD camera Metalic filters Lanex screen+aluminium shield Magnet Deformable mirror f/9 off-axis parabolic mirror Capillary, multimode Electrons and X-rays from Capillaries G. Genoud et al. Submitted 2011

1. Estimation of the source position G. Genoud et al. Submitted (2011) → X-ray emission stops after ~3 mm behind the laser focus Laser focusEnd of X-ray source ? Betatron X-rays from Capillaries

→ upper limit for the transverse source size ~7 µm a b Line-out l l s Detector 2. Estimation of the source size Betatron x-rays from Capillaries

Electron Acceleration at the Lund Laser Centre 10 Hz Multi-TW laser Gas jets Quasi-monoenergetic electrons Stability studies Beam quality studies Wavebreaking studies Betatron X-rays Gas-filled dielectric capillaries Linear plasma waves over long distance Electron acceleration inside capillaries Betaton X-rays emission Plans, facilities... Tomorrow

The MAX-lab test-FEL facility Modulator undulator Chicane Radiator undulator Half-chicane Dog-leg Linac 1Linac 2 Recirculator Gun Dump Gun laser Seed laser Mono- chromator Ti:Sapphire Seed laser Ti:Sapphire Seed laser Ti:Sapphire Gun laser Ti:Sapphire Gun laser Optical fibre