Moderator of 1 Session
Presenter of 1 Presentation
EXPERIMENTAL CHARACTERISATION OF AN ULTRA-HIGH DOSE RATE LASER PLASMA ACCELERATED VHEE BEAM
Abstract
Background and Aims
Accurate dosimetry is paramount for the study of biological effects since dose and dose-rate are critical parameters governing the underlying interaction mechanisms. With the goal of evaluating the suitability of innovative dosimeters in a laser-plasma accelerated electron beam and experimental setup dedicated to radiobiological studies, we evaluated and compared the response of several of these passive and active detectors.
Methods
New developments in compact laser-driven electron beam technologies enable allow to consider the use of very high energy electron (VHEE) beams for radiation therapy and radiobiology applications. Laser-plasma accelerated electron beams with energy up to 300 MeV, large dose per pulse (>1Gy) and ultrashort pulse duration were used to characterise the response of the considered detectors in a large energy/dose rate range. Measurements were simultaneously carried out with EBT-XD radiochromic films, alanine pellets (readout performed with an X-band electron paramagnetic resonance spectrometer equipped with a high Q resonant cavity), a commercial dosimetry solution based on plastic scintillators (Medscint) as well as the new small ionization chamber Razor Nano Chamber (IBA).
Results
Dose rate independent detectors such as the alanine, film and the scintillator were used to cross calibrate the ionization chamber whose ion recombination efficiency was estimated. Mean dose rates and instantaneous dose rates ranging from 1 mGy/s to 0.5 Gy/s and from 1e10 Gy/s to 5e11 Gy/s, respectively, were explored. The dose values obtained with the four dosimeters were compared for various beam configurations.
Conclusions
Several detectors seem to be suitable and reliable for laser-plasma accelerated VHEE irradiation. Promising results in the small number of conditions tested were found and will support the analysis of radiobiological experiments for preclinical research.