The SAABRE project involves the development of a new diagnostic tool to measure the continuous Bremsstrahlung X-ray radiation produced when a high-power laser interacts with matter.
Currently, the instrument known as the Bremsstrahlung Cannon (BC) uses a stack of X-ray-sensitive films separated by filters. Each film absorbs a portion of the incident radiation based on its energy, allowing the energy spectrum of the incident X-rays to be reconstructed. However, these films must be removed from the experimental chamber and scanned after each shot, which severely limits the use of the BC on the new generation of high-repetition-rate lasers (such as APOLLON, VEGA3, or ELI) and complicates its deployment on single-shot facilities like the LMJ.
The project therefore proposes replacing the films with millimeter-sized semiconductor crystals (Si, CdTe, CZT, GaAs, and perovskites). These sensors will enable instantaneous measurement of the radiation dose, conversion of the signal into digitized electrical data analyzed in real time, and adaptation of the instrument to different types of experiments by changing the configuration of the filters used (inertial confinement fusion or laser-plasma acceleration).
The postdoctoral fellow hired will lead the entire development of this new detector, from the study of the proposed semiconductors to the creation of a prototype simulated with GEANT4, which will then be calibrated and experimentally tested on facilities producing high-energy gamma rays. The device will be used in particular for the EUROPA project, dedicated to the production of innovative medical radioisotopes, and will lead to scientific publications and conference presentations.