U.S. flag

An official website of the United States government

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.

PUBLICATIONS

PicoWatt Infrared Power Measurement using an Absolute Cryogenic Radiometer

Published

Author(s)

Stephen Carr, Solomon I. Woods, Timothy M. Jung, Adriaan C. Carter, Raju V. Datla

Abstract

We report on initial measurements of the low-temperature thermal properties of a device that is similar to the experimental apparatus used for absolute cryogenic radiometry (ACR) within the Low Background Infrared Radiometry (LBIR) facility at NIST. The device consists of a receiver cavity mechanically and thermally connected to a temperature-controlled stage through a thin-walled polyimide tube which serves as a weak thermal link. In order to evaluate the functionality of the device for use in a cryogenic radiometer, we measured the thermal resistance and thermal time constant of the system within the temperature range of 1.8 - 4.4 K. The measured thermal resistance and thermal time constant at 1.883 K were 2400 500 (K/mW) and 24 6 (s). This value for the thermal resistance should result in about an order-of-magnitude increase in radiometer sensitivity compared with the present ACR within LBIR. Although the sensitivity should increase by about an order-of-magnitude, the measured time constant is nearly unchanged with respect to previous ACRs within LBIR, due to the reduced dimensions of the receiver cavity. Finally, the thermal conductivity inferred from the measured thermal resistance and geometrical parameters was computed, with an average value of 0.015 (W/m-K), and compared with other measurements of polyimide from the literature.
Proceedings Title
SPIE: Defense Security and Sensing 2009
Volume
7298
Conference Dates
April 13-17, 2009
Conference Location
Orlando, FL
Pub Type
Conferences

Download Paper

Local Download

Keywords

absolute cryogenic radiometer, electrical substitution radiometer, IR, LBIR, NIST, pW power

Citation

Carr, S. , Woods, S. , Jung, T. , Carter, A. and Datla, R. (2009), PicoWatt Infrared Power Measurement using an Absolute Cryogenic Radiometer, SPIE: Defense Security and Sensing 2009, Orlando, FL, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=902597 (Accessed October 5, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created May 7, 2009, Updated February 19, 2017