Stability of superconductors cooled internally with He-II

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5654332

Canavan, E R

In an effort to better understand the stability mechanisms of internally cooled superconductors in the He-II regime, measurements are made on a hollow composite superconductor open at both ends to a bath of subcooled He-II. The vacuum-insulated conductor, 3.2 meters in length and 1.1 millimeters in internal diameter, carries a transport current in a transverse background field of up to 11 Tesla. Heaters mounted on the surface of the conductor at its center are used to initiate local disturbances. By varying the energy applied to the heater at a given current, the stability margin is mapped out. The propagation or collapse of these disturbances for energies just above and below the stability margin is observed using a series of temperature sensors and voltage taps mounted symmetrically about the heater. The conductor is shown to have three regions of stability, each determined by a different heat-transfer mechanism. In the region where resistive power generation is high and the current-sharing temperature i slow, stability is determined by radial diffusion of heat into the local helium. In the region where resistive power generation is low, stability is determined by axial heat diffusion into the He-II.

• Research Organization: Wisconsin Univ., Madison, WI (USA)
• OSTI ID: 5654332
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COOLING
ENERGY TRANSFER
EVEN-EVEN NUCLEI
FLUIDS
HEAT TRANSFER
HELIUM 4
HELIUM II
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAGNETIC FIELDS
NUCLEI
QUANTUM FLUIDS
STABILITY
STABLE ISOTOPES
SUPERCONDUCTING DEVICES
TUBES