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Microwave SQUID Multiplexer demonstration for Cosmic Microwave Background Imagers
- Source :
- Appl. Phys. Lett. 111, 243510 (2017)
- Publication Year :
- 2017
-
Abstract
- Key performance characteristics are demonstrated for the microwave SQUID multiplexer ($\mu$MUX) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the $\mu$MUX produces a white, input referred current noise level of 29~pA$/\sqrt{\mathrm{Hz}}$ at -77~dB microwave probe tone power, which is well below expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure 98~pA$/\sqrt{\mathrm{Hz}}$ in the TES-coupled channels biased at 65% of the sensor normal resistance. This noise level is consistent with that predicted from bolometer thermal fluctuation (i.e., phonon) noise. Furthermore, the power spectral density exhibits a white spectrum at low frequencies ($\sim$~100~mHz), which enables CMB mapping on large angular scales that constrain the physics of inflation. Additionally, we report cross-talk measurements that indicate a level below 0.3%, which is less than the level of cross-talk from multiplexed readout systems in deployed CMB imagers. These measurements demonstrate the $\mu$MUX as a viable readout technique for future CMB imaging instruments.<br />Comment: 6 pages, 4 figures
- Subjects :
- Astrophysics - Instrumentation and Methods for Astrophysics
Subjects
Details
- Database :
- arXiv
- Journal :
- Appl. Phys. Lett. 111, 243510 (2017)
- Publication Type :
- Report
- Accession number :
- edsarx.1710.04326
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1063/1.5008527