Stray-Capacitance As a Simple Tool for Monitoring and Locating Heat Generation Demonstrated in Three Superconducting Magnets
Real-time monitoring of heat loads in cryogenic systems is critical for many applications, particularly high field magnets. In this work, we demonstrated that by monitoring changes in the capacitance of local probes consisting of thin metal strips with a porous glass fiber dielectric, boiling helium from as little as 0.1 J of deposited heat can be located by an analysis of the response speed and amplitude in nearby probes. We further implemented stray-capacitance monitoring of a magnet's metal support structures, a more global probe of the magnet volumes, in three high temperature superconducting Bi-2212 magnet types. Global structural stray-capacitance monitoring was evaluated for a single racetrack coil, a common coil dipole, and a canted cosine theta winding, showing a quench response comparable to voltage signals without inductive effects. The response of the local and global probes was compared in the single racetrack coil with well-known quench properties. Monitoring the cool-down of the common coil dipole demonstrated the added benefit of the global stray-capacitance as a liquid level monitor. This simple method of monitoring the capacitance has proven to be a versatile and robust technique for monitoring and locating heat.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); National High Magnetic Field Laboratory, Tallahassee, FL (United States)
- Sponsoring Organization:
- National Science Foundation (NSF); State of Florida; USDOE Office of Science (SC), High Energy Physics (HEP)
- Contributing Organization:
- Industry partners Yibing Huang with the Bruker OST LLC fabricated high performance Bi-2212 strands for HTS conductor and cabling.
- Grant/Contract Number:
- SC0010421; AC02-05CH11231; SC0014664; DMR-1157 490
- OSTI ID:
- 1864692
- Journal Information:
- IEEE Transactions on Applied Superconductivity, Vol. 31, Issue 6; ISSN 1051-8223
- Publisher:
- IEEECopyright Statement
- Country of Publication:
- United States
- Language:
- English
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