NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Operation of an X-ray transition-edge sensor cooled by tunnel junction refrigerators
Published
Author(s)
Nathan A. Tomlin, James A. Beall, Gene C. Hilton, Kent D. Irwin, Galen O'Neil, Dan Schmidt, Leila R. Vale, Joel Ullom
Abstract
We demonstrate successful cooling of an X-ray transition-edge sensor (TES) using solid-state refrigerators based on normal-metal/insulator/superconductor (NIS) tunnel junctions. Above the TES transition temperature (Tc), we use Johnson noise thermometry to measure the cooling performance. In this regime, the NIS refrigerators cool the TES from 300 mK to 220 mK and from 220 mK to Tc = 160 mK. Below Tc, we clearly see cooling and observe that the operation of the NIS refrigerators introduces no detectable noise into the TES readout. However, due to the complicated thermal circuit, we are currently unable to quantify the cooling below Tc without further measurements.
Tomlin, N.
, Beall, J.
, Hilton, G.
, Irwin, K.
, O'Neil, G.
, Schmidt, D.
, Vale, L.
and Ullom, J.
(2008),
Operation of an X-ray transition-edge sensor cooled by tunnel junction refrigerators, Journal of Low Temperature Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=32750
(Accessed October 9, 2025)