Spectral and spatial shaping of laser-driven proton beams using a pulsed high-field magnet beamline.

Intense laser-driven proton pulses, inherently broadband and highly divergent, pose a challenge to established beamline concepts on the path to application-adapted irradiation field formation, particularly for 3D. Here we experimentally show the successful implementation of a highly efficient (50% transmission) and tuneable dual pulsed solenoid setup to generate a homogeneous (8.5% uniformity laterally and in depth) volumetric dose distribution (cylindrical volume of 5 mm diameter and depth) at a single pulse dose of 0.7 Gy via multi-energy slice selection from the broad input spectrum. The experiments have been conducted at the Petawatt beam of the Dresden Laser Acceleration Source Draco and were aided by a predictive simulation model verified by proton transport studies. With the characterised beamline we investigated manipulation and matching of lateral and depth dose profiles to various desired applications and targets. Using a specifically adapted dose profile, we successfully performed first proof-of-concept laser-driven proton irradiation studies of volumetric in-vivo normal tissue (zebrafish embryos) and in-vitro tumour tissue (SAS spheroids) samples.