Al-Mn Transition Edge Sensors for Cosmic Microwave Background Polarimeters

Published

November 22, 2010

Author(s)

Daniel R. Schmidt, Hsiao-Mei Cho, Johannes Hubmayr, Peter J. Lowell, Michael D. Niemack, Galen C. O'Neil, Joel N. Ullom, Ki W. Yoon, Kent D. Irwin, W L. Holzapfel, M Lueker, E M. George, E Shirokoff

Abstract

Superconducting transition edge sensors (TES) require superconducting films with transition temperatures (Tc)and properties that can be tailored to the particular requirements of individual applications. We have been developing Al-Mn films with a tunable Tc. The addition of Mn to Al suppresses Tc, but does not significantly broaden the superconducting density of states of the Al. We can produce films with Tc from below 50 mK to 1.4 K through adjustment of the Mn concentration. Since this is a bulk effect, Tc is not as dependent on precise control of film thickness as in the standard bi-layer approach for TESs. We have previously used Al-Mn to fabricate TES sensors for x-ray micro-calorimeters targeted for read out with time division SQUID multiplexing schemes. In this work, we explore the properties of Al-Mn in a regime well suited for frequency division multiplexing. We have also fabricated prototype Al-Mn cosmic microwave background polarimeters for the South Pole Telescope and will show initial measurements of these sensors.

Citation

IEEE Transactions on Applied Superconductivity

Volume

21

Issue

3

Pub Type

Journals

Download Paper

https://doi.org/10.1109/TASC.2010.2090313

Local Download

Keywords

superconducting transition edge sensors, TES, superconducting films, transition temperatures, Tc, Al-Mn films, x-ray micro-calorimeters, SQUID multiplexing schemes, South Pole Telescope

Citation

Schmidt, D. , Cho, H. , Hubmayr, J. , Lowell, P. , Niemack, M. , O'Neil, G. , Ullom, J. , Yoon, K. , Irwin, K. , Holzapfel, W. , Lueker, M. , George, E. and Shirokoff, E. (2010), Al-Mn Transition Edge Sensors for Cosmic Microwave Background Polarimeters, IEEE Transactions on Applied Superconductivity, [online], https://doi.org/10.1109/TASC.2010.2090313 (Accessed July 12, 2025)