Laser interactions with micro-targets for imaging applications

ΓRelativistic laser-plasma interactions as drivers for intense and energetic bursts of proton, electron and photon radiation have been studied for more than a decade [1,2,3]. Much of the attention is driven by their potential use in medical physics, to build compact and affordable sources for diagnostics and therapy. So far, these efforts were focused on single species radiation, meaning either ions, electrons or photons, whilst regarding the respective other species as a disturbance [4,5,6].Our experiments make use of the Texas Petawatt laser to drive micro-anodes producing intense proton (tens of MeV, 1012 protons in 4π) and X-ray (10s of keV, 1012 photons in 4π) bursts. These are analyzed spectrally and spatially. Their small source footprint (5 μm) and large brilliance enables compact single-shot X-ray phasecontrast imaging as well as simultaneous bi-modal proton and X-ray imaging of biological specimens. This development could allow for combinations of the superior resolution obtained in X-ray imaging with the superiority of proton-CT in terms of treatment planning for charged particle therapy of cancer. The novel bimodal imaging mode is uniquely enabled by high-power laser-plasma interactions and the particular properties of particle beams generated therein.