Abstract:
A cryogenic bolometer with Neutron
Transmutation Doped Ge as mK thermometer is being developed
to study neutrinoless double beta decay (NDBD) in 124Sn. The
performance and sensitivity of the sensor strongly depends on the
irradiation as well as fabrication (etching, annealing, contact
deposition) process. The role of contact fabrication on the sensor
performance is presented here. The performace of NTD Ge
sensors with wrap-around contact and face-type contacts is
compared at T < 100 mK. It is observed that NTD Ge sensors
with face-type contacts show Mott behaviour upto lower
temperature ~35 mK as compared to that for sensors with wraparound contacts. Further, detailed noise measurements on
several indigeously developed NTD Ge sensors have been carried
out in temperature range of 20-70 mK to understand its impact
on bolometer resolution and have been described in following
section.
