Name: Sandeep Vishwakarma
Affiliation: Tata Institute of Fundamental Research
Conference ID : ASI2022_510
Title : Daksha CZT detectors and front-end electronics: laboratory testing
Authors : Sandeep Vishwakarma (TIFR), Jayprakash Koyande (TIFR), Abhijeet Ghodgaonkar (IIT Bombay), Shriharsh Tendulkar (TIFR), Varun Bhalerao (IIT Bombay)
Abstract Type: Poster
Abstract Category : Instrumentation and Techniques
Abstract : The workhorse of the Daksha mission are Cadmium Zinc Telluride (CZT) detectors. A set of twenty detectors and the front-end electronics are packaged together to make a “Medium Energy Box” (ME Box) that is replicated seventeen times on the Daksha payload. We present results from testing of such an ME box to characterize the system noise and the performance of the detectors. We quantify the noise floor and the presence of noisy pixels in various detectors as a function of the threshold (Low Level Discriminator) values. We also measure variation of detector gain, offset and noise characteristics with changes in the bias high voltage. We test the system at various temperatures in a thermal cycling unit. A lab setup has been designed such that the control equipment can sit outside the thermal chamber, while the ME box and a radioactive source can be placed inside. We cycle the system through a range of temperatures as per the qualification requirement, and measure the detector characteristics at multiple stages. We compare detector performance before and after the cycling test, and quantify any discrepancies.