Project Title: Sub-Kelvin Refrigeration in Zero-g
Project Description:
The sensitivity of a class of detectors used for infrared and X-ray
astronomy is greatly enhanced if they are cooled to below 1K.
Refrigeration to such temperatures is difficult in space, where
refrigerators must be small, use little power, and operate in zero-g.
Temperatures below 0.1K can be reached in the laboratory by
evaporating a dilute mixture of 3He from 4He. A novel technique
enables this classical method to be adapted to zero-g. A prototype
refrigerator exists. The project proposed for the SURF student is to
use this prototype to investigate the feasibility of using this
technique in space. The work will involve laboratory testing of the
prototype refrigerator and thermodynamic analysis of it
performance.
Background Information:
Our group develops novel instrumentation for astrophysics and
cosmology. Most of the instrumentation involves detectors cooled to
below 1K. We currently have experiments operating from ground-based
telescopes on Mauna Kea (the Caltech Sub-mm Observatory), from high
altitude balloons, from sounding rockets, and from satellites. The
3He/4He refrigerator is a candidate for a new mission that we are
developing in collaboration with JPL that is intended to map the 2.7K
Cosmic Microwave Background.
Literature References:
A.E. Lange, M.M. Freund, S. Sato, T. Hirao, T. Matsumoto, and T.
Watabe, "The Far-Infrared Photometer on the Infrared Telescope in
Space", Astrophys. J., 428:384 (1994).
L. Duband, L. Hui, and A. Lange, "A Space-borne 3He Refrigerator",
Cryogenics, 30, 263 (1990).
Requirements:
The sponsor requires that interested students meet the following requirements:
Student must enjoy experimental physics!
This opportunity is for:
Caltech students only
Research Sponsor
Sponsor: Andrew Lange
Division: PMA
Mail Code: 424-47
Phone: x6887
E-mail: ael@tacos.caltech.edu