Evaluation of a Compton camera concept using the 3D CdZnTe drift strip detectors

Abstract

A: At DTU Space, a high-resolution 3D CZT drift strip detector has been developed and a number of prototype detectors were fabricated, allowing for sub-mm position resolution at high energies (>100 keV), as well as high energy resolution. For spectral and spatial performance, the 3D CZT prototype detectors were characterized with a fine collimated high-energy (Cs137) monochromatic beam (0.2 mm × 40 mm) using a digitizer with which the pulse shapes of the bipolar signals from all electrodes could be analysed. Data analysis consist of position determination for single as well as double interaction events handled within the detector. The double interaction events (e.g. Compton interaction) are utilized to characterize the imaging performance of the 3D CZT drift strip detector prototype when operating as a Compton camera.

Performance evaluation of MACACO II Compton camera

“…In spite of the above, in an attempt to compare our results with other published work, the published results obtained at the same energy have been selected. As expected, the energy resolution of our system falls behind the results with solid-state detectors [23,24], but it is superior to the systems employing GAGG scintillator crystals coupled to SiPMs, which quote energy resolution of 15.06 % FWHM [25] and 9.7 % FWHM [26] at 511 keV.…”

Potentialities of High-Resolution 3-D CZT Drift Strip Detectors for Prompt Gamma-Ray Measurements in BNCT

“…Each drift cell is characterized by a collection anode, the RD and LD strips and the 10 cathode strips. Each drift cell is able to provide both the energy and the 3-D interaction position of the photons, as already demonstrated in the literature [34,35]. In particular, the energy of the photons can be given by the pulses from the collecting anodes, the x-position by the collecting anodes related to the RD/LD anode pulses, the y-position through the relation between the cathode and the anode pulses and the z-position by the cathode pulses.…”

“…Since then, great efforts and successful results have been obtained in the development of high-resolution CZT detectors, in terms of both crystal growth [27,28] and device/electrode technology [29][30][31][32]. CZT detectors with orthogonal anode and cathode strips were fabricated since 1996 [33] and important advances were obtained at the DTU Space (Denmark) for astrophysical applications [34,35]. The strip electrode layout and the drift strips allow charge collection enhancements and sub-millimeter 3-D spatial capabilities.…”

“…In particular, the energy of the photons can be given by the pulses from the collecting anodes, the x-position by the collecting anodes related to the RD/LD anode pulses, the y-position through the relation between the cathode and the anode pulses and the z-position by the cathode pulses. Despite a pitch of 1.6 mm of the drift cells and 2 mm of the cathode strips, it is possible to reduce the spatial resolution through the analysis of the pulses from the drift strips [34,35].…”

Use of a Si/CdTe Compton Camera for In vivo Real-Time Monitoring of Annihilation Gamma Rays Generated by Carbon Ion Beam Irradiation

“…A Compton camera is a compact (i.e., ∼44.5 × 34.0 × 23.5 cm in size) device that can detect multiple radionuclides exhibiting a wide energy range (from a few hundred keV up to few MeV) simultaneously. These features indicate the device's potential for applications in medical imaging (6)(7)(8)(9)(10)(11)(12)(13).…”