Quantum Efficiency Measurement and Modeling of Silicon Sensors Optimized for Soft X-ray Detection.

Hybrid pixel detectors have become indispensable at synchrotron and X-ray free-electron laser facilities thanks to their large dynamic range, high frame rate, low noise, and large area. However, at energies below 3 keV, the detector performance is often limited because of the poor quantum efficiency of the sensor and the difficulty in achieving single-photon resolution due to the low signal-to-noise ratio. In this paper, we address the quantum efficiency of silicon sensors by refining the design of the entrance window, mainly by passivating the silicon surface and optimizing the dopant profile of the n region.

Performance of LGAD strip detectors for particle counting of therapeutic proton beams.

. The performance of silicon detectors with moderate internal gain, named low-gain avalanche diodes (LGADs), was studied to investigate their capability to discriminate and count single beam particles at high fluxes, in view of future applications for beam characterization and on-line beam monitoring in proton therapy..

Calibration method and performance of a time-of-flight detector to measure absolute beam energy in proton therapy.

Background: The beam energy is one of the most significant parameters in particle therapy since it is directly correlated to the particles' penetration depth inside the patient. Nowadays, the range accuracy is guaranteed by offline routine quality control checks mainly performed with water phantoms, 2D detectors with PMMA wedges, or multi-layer ionization chambers. The latter feature low sensitivity, slow collection time, and response dependent on external parameters, which represent limiting factors for the quality controls of beams delivered with fast energy switching modalities, as foreseen in future treatments.

Small field correction factors determination for several active detectors using a Monte Carlo method in the Elekta Axesse linac equipped with circular cones.

A Monte Carlo (MC) method was used to determine small field output correction factors for several active detectors (Exradin A16, Exradin A26, PTW microLion, PTW microDiamond, Exradin W1 and IBA RAZOR) for an Elekta Axesse linac equipped with circular cones. MC model of the linac was built with the GamBet software, using the Penelope code system. The dose-to-water simulation for each cone, ranging from 5 to 30 mm of diameter size, was used to calculate field factors and the results were validated together with Gafchromic EBT3 film.