  LiteBIRD is a proposed JAXA satellite mission to measure the CMB B-mode
polarization with unprecedented sensitivity ($\sigma_r\sim 0.001$). To achieve
this goal, $4676$ state-of-the-art TES bolometers will observe the whole sky
for 3 years from L2. These detectors, as well as the SQUID readout, are
extremely susceptible to EMI and other instrumental disturbances e.g. static
magnetic field and vibration. As a result, careful analysis of the interference
between the detector system and the rest of the telescope instruments is
essential. This study is particularly important during the early phase of the
project, in order to address potential problems before the final assembly of
the whole instrument. We report our plan for the preparation of a cryogenic
testbed to study the interaction between the detectors and other subsystems,
especially a polarization modulator unit consisting of a magnetically-rotating
half wave plate. We also present the requirements, current status and
preliminary results.
