Plasmaphysik Seminar

Laser ion acceleration using the Draco Petawatt facility at HZDR - experiments and radio-biological application

by Dr. Karl Zeil (Helmholtz-Zentrum Dresden-Rossendorf)

Tuesday, April 30, 2019 from to (Europe/Berlin)
at GSI Darmstadt ( Seminarraum Theorie )
Demanding applications like radiation therapy of cancer are pushing the frontier of laser driven proton accelerators with controlled and well-defined proton beam properties. This talk will give an overview of recent achievements at the high-contrast high power laser source DRACO at HZDR. The laser system was recently upgraded by an additional Petawatt (PW) amplifier stage and new front end components finally providing high contrast pulses of >500 TW on target at 1 Hz pulse repetition rate. With the new PW beam line of Draco the feasibility of worldwide first controlled volumetric irradiation of a specifically developed tumor model, grown on the ears of nude mice with laser-accelerated protons are investigated.  In order to efficiently capture and shape the divergent TNSA proton beam, a setup of two pulsed high-field solenoid magnets has been developed and applied. The talk will summarize results of the reliable generation of homogeneous depth dose distributions and first irradiation of three-dimensional samples.
The performance of laser based ion acceleration and the scaling of the laser energy to achieve increased ion energies strongly depend on the laser temporal contrast and its effect on the target plasma scale length. Plasma mirror setups have proven to be a valuable tool to significantly improve the temporal contrast by reducing pre-pulse intensity and steepening the rising edge of the main laser pulse.  With such contrast enhancement techniques laser proton acceleration using ultra-thin foil targets as well as a renewable debris-free hydrogen jet (in collaboration with SLAC and European XFEL) target has been investigated in a series of experiments within the TNSA regime. An important implication of this is the demonstration of a credible path toward high repetition rate laser-based ion acceleration applications.