학술논문

Modeling TES Nonlinearity Induced by a Rotating HWP in a CMB Polarimeter.
Document Type
Article
Source
Journal of Low Temperature Physics. Jun2023, Vol. 211 Issue 5/6, p357-365. 9p.
Subject
*PINK noise
*OPTICAL elements
*BOLOMETERS
*OPTICAL telescopes
*VERY large array telescopes
*POLARISCOPE
Language
ISSN
0022-2291
Abstract
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 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. [ABSTRACT FROM AUTHOR]