Design and Characterization of a Compton Camera Using 3D-CZT Detector Modules with Advanced Signal Processing and Polarimetry for MeV Astrophysics

The energy range between 0.1 MeV and 10 MeV is called as “MeV gap” in astronomy, primarily due to the low sensitivity of the instruments in this energy range. Compton imaging is the key technique proposed to overcome this challenge. The goal of this project is to design a cost-efficient Compton Imager. CZT detectors have the potential to be game changers when used in a Compton Imager, since they offer good energy resolution at room temperatures. Hence in this project, we plan to design, simulate and calibrate a Compton Camera based on the 3D-CZT Drift Strip Detectors, developed previously at DTU Space, Technical University of Denmark. An additional advantage is that the Compton Imager could be used as a hard X-ray polarimeter, as azhimuthal angle of the Compton scattering depends on the polarization of the incoming photon. Recent observations from the Imaging X-ray Polarimetry Explorer (IXPE) have attracted massive interest from the high-energy astrophysical community towards X-ray polarimetry. However, IXPE operates in the soft X-ray band of 2-8 keV, where the thermal processes interlap with non-thermal processes. Hence, a polarimeter in the MeV band where the non-thermal radiative process dominates is of large interest. We plan to design a laboratory model of the Compton telescope using a stacked configuration of 3D CZT detectors and evaluate its imaging and polarimetry performance through simulations followed by experimental validation. The recent development of this detector includes using Artificial Neural Networks for sensor Signal Processing and Real-time measurement of radiation interactions which would also be ideal for this project. The immense expertise of the host supervisor and group in semiconductor detectors would complement the candidate's experience in X-ray polarimetry to accomplish the project.