V. Bagnoud PHELIX, Plasma Physics department GSI Darmstadt Status of the LIGHT project Laser ion Generation Handling and Transport V. Bagnoud PHELIX, Plasma Physics department GSI Darmstadt Photo M-Zweig ausgetauscht EMMI Workshop: Nonlinear Dynamics of Simple Quantum Systems at Extreme Temperatures and Intensities

LIGHT coordinates activities in the field of particle acceleration at GSI LIGHT aims at injecting laser-accelerated ions into conventional accelerator structures The key factor is the transport of the source peak brilliance The core LIGHT project is under realization at the Z6 Experiment place of GSI The principle elements have been demonstrated separately Integration will happen in 2012 Additional studies are being followed outside the baseline design to improve the setup performance Reduction of the ion initial divergence by means of engineered laser beams is being investigated Higher source brilliance via energy-peaked spectral distributions by RPA

Motivation: GSI is the ideal place to conduct this project Leading expertise in both fields (laser acceleration, accelerator technology) available at GSI, surrounding universities, and HIJ Z6 Target Area PHELIX Optimal use of laser accelerated ions requires beam forming, energy selection and debunching Z6 target area provides access to the PHELIX laser beam and to accelerator hardware (e.g. test beam, RF equipment, diagnostics) We can provide a versatile testbed to study laser-accelerated particles in conventional accelerator structures

Project phases of the core LIGHT project Post-acceleration structure Target chamber Solenoid Ion beam diagnostic Debuncher cavity UNILAC beam Short pulse diagnostics

Contributions / Responsibilities Helmholtz Institute Jena Coordination Development and setup of a 100TW compressor for a 12 cm sub-aperture beam of PHELIX Short-pulse diagnostics GSI PHELIX/PP, Acc., Beam Diagnostics, AP Laser, timing, control system Beamline to target chamber Accelerator structures Proton beam diagnostics FZ Dresden-Rossendorf Solenoid for collimation + PSU TU Darmstadt PI, Acceleration experiments Collimation simulations, target development JWG University Frankfurt Accelerator structure development

Timeline 2010 2011 2012 beyond Compressor setup √ Beamlines √ 100 TW pulses in target chamber √ Collimation and ion beam shaping √ Proton pulse diagnostics √ Test of rebuncher structure with UNILAC proton beam √ Injection into rebuncher structure Injection into post-acceleration structure Laser acceleration experiments with higher repetition rate at JETI, POLARIS, DRACO and PHELIX Possibility to inject into SIS 18 Higher repetition rate at Z6 Prepairing a technical design report

Ion beam angular distribution Other studies in the framework of LIGHT Ion beams from engineered laser beams Ion beam angular distribution Electron sheath

Lower initial ion beam divergence with engineered laser beams Hollow Beam Project: Lower TNSA proton divergence by engineering the electron sheath Achieved by custom continuous phase masks changing the focal spot intensity (x1018 W/cm2) Predicted electron sheath -30 Annular Laser Beam Focus 20 -20 15 -10 Y (micrometers) 10 10 20 5 30 -30 -20 -10 10 20 30 X (micrometers)

Modified Laguerre-Gaussian modes have been developed at PHELIX A helix-type phase mask is inserted in the front end of PHELIX, together with an amplitude mask with a dark spot in the center (singularity) We simulated the influence of aberrations and phase errors to the focal spot We optimized the maximum energy (fill factor) and the expected intensity distribution in the far field Results are used as input for PIC simulations for the proton beam characteristics and choice of the right target foil dimensions. Input with amplitude mask

Preliminary necessary improvements to the PHELIX laser Optimization of the beam wavefront at the main amplifier input before after Simulation and preliminary tests showed the sensitivity of the beam to aberrations A dedicated beam time (P041) was used to improve the PHELIX laser beam quality Measurement of the wave front aberrations at different locations throughout the PHELIX laser chain Most improvements / changes were done to the Main Amplifier injection and our quasi-deformable double-pass mirror (MM1) Phase (0.9 l PtV) Phase (0.2 l PtV) Far field Far field This effect could be seen in the Focal spot quality after the Main Amplifier

The control of low-order aberrations allowed to implement hollow beam The hollow beam propagates through the PHELIX laser chain with the right aperture size for the LIGHT project / 100 TW beam line (12 cm). Near Field Far field Far field Optimized phase masks also helped for larger apertures, but still room for improvement to match the maximum size of the PW Compressor in the PHELIX hall. 16 cm Smooth beam with optimized phase mask Preamplifier output with 16 cm beam Compressor output with 12 cm beam The use of adaptive optics is being investigated for higher control levels

Our next steps 2D and 3D PIC simulations based on simulated and experimentally verified ion beams Measurements at the target chamber center (currently not available) Validation experiments

LIGHT coordinates activities in the field of particle acceleration at GSI LIGHT aims at injecting laser-accelerated ions into conventional accelerator structures The key factor is the transport of the source peak brilliance The core LIGHT project is under realization at the Z6 Experiment place of GSI The principle elements have been demonstrated separately Integration will happen in 2012 Additional studies are being followed outside the baseline design to improve the setup performance Reduction of the ion initial divergence by means of engineered laser beams is being investigated Higher source brilliance via energy-peaked spectral distributions by RPA