Spectral and directional sensitive composition characterization of mixed-radiation fields with the miniaturized radiation camera MiniPIX Timepix2

Abstract

The semiconductor pixel detector Timepix2 is operated with highly integrated readout electronics as a miniaturized and portable MiniPIX TPX2 radiation camera for radiation imaging and spectral-sensitive particle tracking in wide field-of-view. The device provides room-temperature operation, ease of use (single USB 2.0 port), online response with single track visualization, fast frame readout (up to 60 fps) and double per-pixel response for detailed measurements with per-pixel energy and counting or energy and timing sensitivity. We evaluate the response and applicability of a MiniPIX TPX2 camera with the Timepix2 ASIC chip equipped with a 300 µm thick silicon sensor for wide-range composition and spectral characterization of mixed-radiation fields. Measurements were performed in high-energy proton radiotherapy environments with protons of selected energies in the range 225–70 MeV and water-equivalent targets of varying configuration (size, dimension, geometry). High-resolution pattern recognition and spectral-tracking analysis of the single particle tracks in the pixelated detector enable to resolve and classify all detected signals according particle species, direction and energy loss. Based on the experimental calibrations performed with well-defined radiation fields together with quantum imaging visualization of single particle tracks, ten broad-range particle-event classes are resolved. Mixed-radiation fields are thus analyzed according particle-event types in wide range of deposited energy, linear-energy-transfer LET, particle fluxes and dose rates. The spatial distribution over the detector sensor matrix of the distinguished groups can be visualized as well as the directional mapping of energetic charged particles.

Detection of fast neutrons with the pixel detector Timepix3

“…The particle-event type classification has been derived from calibration measurements performed with the same detector (MiniPIX TPX3 500 μm silicon sensor, serial number D05) on well-defined radiation fields provided by particle accelerator beams (electrons, protons, light ions) and X-ray tubes and radionuclide gamma-ray sources ( 241 Am, 60 Co, 137 Cs). The detector response matrix was developed and refined in similar approach as for the Timepix 300 μm silicon detector [20] and Timepix2 300 μm silicon sensor [29]. The response matrix is determined by filter values to selected cluster analysis parameters [20] together with the detector spectral and track visualization response [29].…”

“…The detector response matrix was developed and refined in similar approach as for the Timepix 300 μm silicon detector [20] and Timepix2 300 μm silicon sensor [29]. The response matrix is determined by filter values to selected cluster analysis parameters [20] together with the detector spectral and track visualization response [29]. The resulting ten classes [29] represent broad-level particle-event types without cross overlap in between.…”

“…The response matrix is determined by filter values to selected cluster analysis parameters [20] together with the detector spectral and track visualization response [29]. The resulting ten classes [29] represent broad-level particle-event types without cross overlap in between. Any event in the detector can be analysed and is unambiguously assigned to a single class [20,29].…”

“…The resulting ten classes [29] represent broad-level particle-event types without cross overlap in between. Any event in the detector can be analysed and is unambiguously assigned to a single class [20,29].…”

Optimizing and characterizing the Timepix2 hybrid pixel detector: enhancing performance and precision for scientific and industrial applications

“…To address this need, the MiniPIX TimePix2 device, developed by Advacam s.r.o., has been designed as a small and compact X-ray and high energy particle detector suitable for wide range of industrial applications, including space applications, with mechanical robustness and low power consumption [4]. Harvesting the experience with a similar devices, MiniPIX Timepix and Timepix3, that are currently being used in the industry and space research [5,6], this new device was designed to meet as many requirements as possible.…”