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Laser plasma proton accelerators have long been discussed and exploited as drivers of high dose rate applications based on the high number of accelerated particles and the process inherent short pulse duration [1]. Recent development in laser technology, refined real-time laser and plasma diagnostics, and corresponding on-site target preparation enabled the reliable and reproducible generation of proton spectra of up to 80 MeV at DRACO-PW at laser pulse energies of the order of 15 J over many month [2]. Combined with dedicated energy selective pulsed magnet based beam transport systems [3] and adapted on-shot dosimetry instrumentation two series of volumetric irradiation of biological samples were performed. At high precision with respect to predefined dose value and homogeneity dedicated tumors prepared in the ear of mice were irradiated with a single dose value of 4 Gy and referenced to conventional irradiation at same integrated dose at the clinical proton cyclotron in Dresden. In contrast, highest single-shot values of beyond 20 Gy could be applied at only slightly reduced beam quality to tackle the regime of FLASH irradiation. Zebra-fish embryos were irradiated at three different dose values in order to study dose-rate effects with proton beams. Data of both experiments is currently evaluated and the talk will discuss the methods used in detail as well as the outcome and perspectives of the radiobiological studies.
[1] F. Albert, et al., 2020 Roadmap on Plasma Accelerators, New Journal of Physics (2020) https://doi.org/10.1088/1367-2630/abcc62
[2] T. Ziegler, et al., Proton beam quality enhancement by spectral phase control of a PW-class laser system, https://arxiv.org/abs/2007.11499 (2020)
[3] F. Brack, et al., Spectral and spatial shaping of laser-driven proton beams using a pulsed high-field magnet beamline, Scientific Reports 10, 9118 (2020) and presentation at this conference
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