Modelling TES non-linearity induced by a rotating HWP in a CMB polarimeter

Kavli Affiliate: Tomotake Matsumura

| First 5 Authors: Tommaso Ghigna, Tomotake Matsumura, Yuki Sakurai, Ryota Takaku, Kunimoto Komatsu

| Summary:

Most upcoming CMB experiments are planning to deploy between a few thousand
and a few hundred thousand TES bolometers in order to drastically increase
sensitivity and unveil the B-mode signal. Differential systematic effects and
$1/f$ noise are two of the challenges that need to be overcome in order to
achieve this result. In recent years, rotating Half-Wave Plates have become
increasingly more popular as a solution to mitigate these effects, especially
for those experiments that are targeting the largest angular scales. However,
other effects may appear when a rotating HWP is being employed. In this paper
we focus on HWP synchronous signals, which are due to intensity to polarization
leakage induced by a rotating cryogenic multi-layer sapphire HWP employed as
the first optical element of the telescope system. We use LiteBIRD LFT as a
case study and we analyze the interaction between these spurious signals and
TES bolometers, to determine whether this signal can contaminate the bolometer
response. We present the results of simulations for a few different TES model
assumptions and different spurious signal amplitudes. Modelling these effects
is fundamental to find what leakage level can be tolerated and minimize
non-linearity effects of the bolometer response.

| Search Query: ArXiv Query: search_query=au:”Tomotake Matsumura”&id_list=&start=0&max_results=10

Read More