Abstract Details

Name: Sonal Patel
Affiliation: TIFR, Mumbai
Conference ID: ASI2019_107
Title : Expected performance parameters of the G-APD (SiPM) based imaging atmospheric Cherenkov Gamma-ray telescope
Authors and Co-Authors : S. R. Patel, V. R. Chitnis, S. S. Upadhya, K. S. Gothe, B. K. Nagesh, B. B. Singh, S. K. Rao and S. Duhan
Abstract Type : Oral
Abstract Category : Instrumentation and Techniques
Abstract : The HAGAR group in TIFR is developing 256-pixel camera with G-APDs as photo-sensor for 4m class ground based imaging atmospheric Cherenkov Gamma-ray telescope. G-APDs are chosen instead of PMTs, for unbiased monitoring of bright blazars, as G-APD based telescope has longer duty cycle than the PMT based one. In order to understand the performance of the camera, Monte Carlo simulations of extensive air showers are carried out for very high energy Gamma-rays and cosmic rays. Various topological trigger criteria are examined to decide the optimum operating trigger condition. The shower information are extracted by parameterization of the recorded images in the camera using Hillas parameters. We have calculated two more parameters, viz., Time RMS and Time gradient, which make use of arrival time information of Cherenkov photons, besides the information of photo-electron distribution over the camera plane. Along with the performance parameters like energy threshold, collection area, trigger rates, sensitivity is also estimated, which largely depends on how well the rejection of predominant background of cosmic rays is achieved. The conventional Gamma-Hadron separation methods namely supercuts and dynamic supercuts, along with multivariate method like Random Forest which helps in better rejection of cosmic rays, will be discussed.