Detectors for rare events

In collaboration with the scientists of the Astro-particle Physics and Cosmology (APC) division of SINP, work has been initiated on the search for WIMPs as cold dark matter candidates. This is a collaborative work as part of PICASSO experiment stationed at the Sudbury Neutrino Observatory (SNOLAB), Canada. This has evolved from the in-house developmental work on superheated drop detector (SDD) for radiation detection and dosimetry. Recent activities include development of electret microphone based acoustic pulse detector to go with SDD for fast neutron spectroscopy, wide bandwidth acoustic pulse detection technique using commercially available MEMS based piezoelectric sensors, exploration of neutron and gamma response using radioactive source, neutron gamma discrimination by pulse analysis, and GEANT based simulation of the SDD response. Studies on neutrinoless double beta decay using CdZnTe detectors have also been initiated. Major interest in ths study is the exploration of the unconventional double positron decay mode, which is relatively easy to detect without significant background contamination. In collaboration with IIT Kharagpur, members are involved in planning and setting up of a double beta decay experiment. Initial study on contamination level of CdZnTe, procured from CEL, New Delhi, has been carried out.