Spectral tracking of proton beams by the Timepix3 detector with GaAs, CdTe and Si sensors

Abstract

Position and directional-sensitive spectrometry of energetic charged particles can be performed with high resolution and wide dynamic range (energy, direction) with the hybrid semiconductor pixel detectors Timepix/Timepix3. The choice of semiconductor sensor material, thickness, and properties such as the reverse bias voltage, greatly determine detector sensitivity and resolving power for spectrometry and particle tracking. We investigated and evaluated the spectral tracking resolving power such as deposited energy and linear-energy-transfer (LET) spectra with the Timepix3 detector with different semiconductor sensors, based on GaAs:Cr, CdTe, and Si, using well-defined radiation sources in terms of radiation type (protons), energy, and incident direction to the detector sensor. Measurements of particle incident direction in a wide range were performed with collimated monoenergetic proton beams of various energies in the range 8–31 MeV at the U120-M cyclotron at the NPI CAS Rez near Prague. All detectors were per-pixel calibrated. This work enables to examine and perform a detailed study of charge sharing and charge collection efficiency in semiconductor sensors. The results serve to optimise the detector chip-sensor assembly configuration for measurements especially with high-LET particles in ion radiotherapy and outer space. The work underway includes evaluation of newly refined semi-insulating GaAs sensors and improved radiation hard semiconductor sensors SiC.

Thermal neutron detection and track recognition method in reference and out-of-field radiotherapy FLASH electron fields using Timepix3 detectors

“…In addition, this tool supports the customization of data analysis by the implementation of filters and masks. The filters are a set of cluster parameters exclusion intervals that can be set to remove background or unwanted events (Novak et al 2023). The cluster features were used as inputs for training a neural network for particle classification, and a complete list of the used parameters is provided in table 1.…”

Conversion of fast neutrons for neutron radiography with TPX2 detector

“…The sensor is typically made of Si (silicon), nevertheless, also other semiconductor materials are being used, e.g. CdTe, GaAs, or recently also SiC [9][10][11][12][13]. The MiniPIX TPX2 detector is prepared by bump-bonding a pixelated sensor to a Timepix2 readout ASIC chip [8], with a matrix of 256 × 256 pixels with 55 m pitch covering an area of 1.4 cm × 1.4 cm.…”

Silicon Carbide Timepix3 detector for quantum-imaging detection and spectral tracking of charged particles in wide range of energy and field-of-view

“…The Timepix detectors provide valuable capabilities of position-, time-and directional sensitivity which make them suitable for selective detection and high-resolution wide-range spectral tracking of single particles [14,15]. The detector high granularity and per-pixel spectral response can be used to examine and evaluate the uniformity and homogeneity of the radiation response and charge collection of the semiconductor sensor [16].…”

“…Therefore, only a small part of the energy deposited by passing high-energy particles is collected in the 65 μm thick volume of the SiC sensor. This limitation extends to other parameters, such as morphological characteristics, where the boundaries between different particle groups are less distinct than in thick (i.e., ≥ 300 μm thick) fully depleted sensors such as Si, CdTe, or GaAs [16]. Only a few parameters are suitable for high-energy particle filtration, and for this task, the deposited energy and cluster size have proven to be the most effective whilst maintaining the high quality of the cleanliness of the filtered dataset.…”