This note describes a possible solution to the training problems that have been observed in many superconducting coils. In particular the proposed technique should apply to bath-cooled coils that are not designed to recover thermally from a small normal region. As a result these coils quench, but th
Adiabatic demagnetization cooler for infrared detector
โ Scribed by T. Yazawa; A. Sato; J. Yamamoto
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 399 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0011-2275
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โฆ Synopsis
An adiabatic demagnetization cooler with an indirectly cooled superconducting magnet was fabricated for an infrared detector. The operating temperature was designed to be 0.2 K. The temperature of the sensor, which replaced the infrared detector, was successfully maintained at 0.200-0.205 K for 7 h by active magnetic field control, using single crystal chromic potassium sulphate as a magnetic working substance. Using manganese ammonium sulphate, a temperature below 0.300 K was maintained for over 12 h, although the lowest sensor temperature was 0.237 K. Yttrium aluminium garnet doped with the magnetic impurity neodymium ion (Nd 3รท) was also tested, it being a substitute for paramagnetic salts from the viewpoint of easy processing and handling. Using this garnet a temperature of 0.203 K could be obtained, though this could only be maintained for 6 min. A proposal for improvement in the garnet cooling capacity has been made.
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