Ground Calibration of the Spatial Response and Quantum Efficiency of the CdZnTe Hard X-ray Detectors for NuSTAR
• +3
• Brian Grefenstette,
• varunbhalerao,
• vrana,
• miyasaka,
• kitaguti
Brian Grefenstette
California Institute of Technology (Caltech)
Author Profile
Pixelated Cadmium Zinc Telluride (CdZnTe) detectors are currently flying on the Nuclear Spectroscopic Telescope ARray (NuSTAR) NASA Astrophysics Small Explorer. While the pixel pitch of the detectors is $$\approx$$ 605 $$\mu$$m, we can leverage the detector readout architecture to determine the interaction location of an individual photon to much higher spatial accuracy. The sub-pixel spatial location allows us to finely oversample the point spread function of the optics and reduces imaging artifacts due to pixelation. In this paper we demonstrate how the sub-pixel information is obtained, how the detectors were calibrated, and provide ground verification of the quantum efficiency of our Monte Carlo model of the detector response.