Automatic temperature control of a superconducting bolometer

✍ Scribed by I.A. Khrebtov; N.M. Gopshtein; G.A. Zaitsev

• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 180 KB
• Volume: 12
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(72)90142-7

✦ Synopsis

exhibited very large boil-offs at currents beyond 600 A. The resistance ratio of the copper, measured at 290 K and 4.2 K was 398. This corresponds to the second column of Table . The temperature distributions for the same purity copper calculated on the basis of equations 8 and 3 are displayed as curves A and B respectively in Fig. . For reference, the electrical resistivity, p, and the product WT, are also shown (curves C and D) in reduced coordinates as functions of temperature. The value of the series resistor required to keep the temperature distribution between the two limiting curves was calculated from (12). When this was installed currents up to 1 200 A produced only moderate boil-offs.

In conclusion, it would seem that the installation of a resistor below the liquid level of a helium bath has definite advantages if high currents are passed intermittently. It also provides a simple method of uprating existing optimized lead assemblies and it may well offer a useful additional control in continuously operating high current cryogenic systems.