RadiaBeam, Santa Monica, USA
LLNL, Livermore, California, USA
MIT, Cambridge, Massachusetts, USA
UCLA, Los Angeles, California, USA
Penn State University, University Park, Pennsylvania, USA
BNL, Upton, Long Island, New York, USA
Because of the broad application space for compact, 1-2 GeV accelerators, Inverse Free Electron Lasers (IFELs) are enjoying a rebirth of R&D funding. The efforts are under way in industry (RadiaBeam), academia (UCLA), and national laboratories (LLNL and BNL) to develop an ultra-compact IFEL energy booster for the photoinjector driven linear accelerating systems. The RUBICON collaboration integrates many of the institutions for proof-of-principle IFEL driven Inverse Compton Scattering (ICS) compact light source demonstrations. IFELs perform optimally in this mid-energy range, and given continual advances in laser technology, high average power IFELs with gradients well over 500 MeV/m are now feasible, leading to high quality, compact ICS and Free Electron Laser light sources. Importantly, IFEL operation can have excellent shot-to-shot energy stability, which is crucial when not only driving these light sources, but also for the downstream applications such as photofission, nuclear resonance fluorescence and standoff detection.
BNL, Upton, Long Island, New York, USA
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
Laser acceleration of ion beams is normally realized via irradiating thin-foil targets with near-IR solid-state lasers with up to petawatt (PW) peak power. Despite demonstration of significant achievements, further progress towards practical application of such beam sources is hindered by the challenges inherent in constructing still more intense and higher-contrast lasers. Our recent studies of the radiation pressure acceleration indicate that the combination of a 10-μm CO2 laser with a gas jet target offers a unique opportunity for a breakthrough in the field. Strong power scaling of this regime holds the promise of achieving the hundreds of MeV proton beams with just sub-PW CO2 laser pulses. Generation of such pulses is a challenging task. We discuss a strategy of the CO2 laser upgrade aimed to providing a more compact and economical hadron source for cancer therapy. This include optimization of the method of the 10μm short-pulse generation, higher amplification in the CO2 gas under combined isotopic and power broadening effects, and the pulse shortening to a few laser cycles (150-200 fs) via self-chirping in the laser-produced plasma and the consecutive dispersive compression.