2021/11/19(Fri)
11:00 -12:00
五樓第一會議室 5F, 1st Meeting Room
視訊演講 Video Seminar [ Meeting Link / ID: 2556 / Password: ynUuMK8YV66 ]
Title
Challenge to temperature noise of POLARBEAR-2: From 0.3 K to 300 K
Speaker
Dr. Daiki Tanabe (Department of Physics, National Central University)Abstract
Observations of the cosmic microwave background (CMB) have played an essential role to establish the Big Bang cosmology and to constrain parameters of the Lambda-CDM model. POLARBEAR-2 is one of the ground-based CMB observation projects which is located in Atacama highland, Chile. It aims to precisely measure B-mode (curl) polarization pattern of the CMB in scales from sub-degree to degree angle for constraining the summation of neutrino masses and inflationary tensor-to-scalar ratio. The millimeter-waves receiver of POLARBEAR-2 deploys 7,588 superconducting detectors on a 0.3 Kelvin cold stage. Beyond just cooling the detector stage, the temperature fluctuation needs to be stabilized enough to achieve high sensitivity. Furthermore, also the room-temperature components, such as mirrors and readout electronics, have their requirements on temperature stability. In this talk, I introduce the cryogenic and readout techniques of POLARBEAR-2 focusing on non-negligible thermal effects on them.
Language
演講語言 (Language): in English
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