  This paper reports the detailed noise characterization, investigation of
various noise sources and its mitigation to improve the performance of a
cryogenic bolometer detector. The noise spectrum has been measured for a
sapphire bolometer test setup with indigenously developed NTD Ge sensor in the
CFDR 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 a cryogenic bolometer is assessed. A systematic
comparison of the influence of different noise pickups on the bolometer
resolution is also presented. The best-achieved resolution at 15mK is ~15 keV
for heater pulses and appears to be mainly limited by the noise due to the
pulse tube cryocooler.
