Modelling TES non-linearity induced by a rotating HWP in a CMB polarimeter
Modelling TES non-linearity induced by a rotating HWP in a CMB polarimeter
复制标题
对 CMB 旋光计中旋转 HWP 引起的 TES 非线性进行建模
DOI：
10.1007/s10909-023-02939-5
复制
发表时间：
2023
影响因子：
2
通讯作者：
Tommaso Ghigna
中科院分区：
文献类型：
--
作者：
上村尚平;大木洋;Tommaso Ghigna
大多数即将进行的CMB实验都计划部署几千到几十万个TES辐射热计，以大幅提高灵敏度并揭示b模式信号。为了实现这一结果，差分系统效应和1/fnoise是需要克服的两个挑战。近年来，旋转半波片作为减轻这些影响的解决方案越来越受欢迎，特别是对于那些以最大角度尺度为目标的实验。然而，当使用旋转HWP时，可能会出现其他效果。本文主要研究了由旋转低温多层蓝宝石HWP作为望远镜系统第一光学元件所引起的偏振泄漏强度引起的HWP同步信号。我们以LiteBIRD LFT为例，分析了这些杂散信号与TES测热计之间的相互作用，以确定这些信号是否会污染测热计的响应。我们给出了几种不同的TES模型假设和不同的杂散信号幅度的仿真结果。对这些效应进行建模是找出可以容忍的泄漏水平和最小化辐射热计响应的非线性效应的基础。
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 theB-mode signal. Differential systematic effects and 1/fnoise 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 multilayer 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. Modeling these effects is fundamental to find what leakage level can be tolerated and minimize nonlinearity effects of the bolometer response.