Abstract:
This paper reports the detailed noise characterization, investigation of various noise sources, and its mitigation to improve the performance
of a cryogenic bolometer detector for the TIN.TIN experiment. The noise spectrum has been measured for a sapphire bolometer test setup
with an indigenously developed neutron transmutation doped Ge sensor in the cryogen free dilution refrigerator system at Mumbai. The
effect of external noise, arising either from ground loops in the system or from the diagnostic and control electronics of the cryostat, on the
performance of the bolometer is assessed. A systematic comparison of the influence of different noise pickups on the bolometer resolution is
also presented. The best-achieved resolution (σE) at 15 mK is ∼15 keV for heater pulses and appears to be mainly limited by the noise due to
the pulse tube cryocooler.
