Stabilization of superconducting dry solenoids

Degradation of the performance of a YBCO-coated conductor double pancake coil due to epoxy impregnation

“…The radial stress distribution in an epoxy impregnated double pancake coil due to winding, cool down, and Lorentz force has been numerically analyzed. [9][10][11][12] Each of the coil form, conductor and insulator layers is regarded as an infinitely long thin cylinder, contacting elastically each other. Continuity of the radial-displacement and radial-stress at the interfaces gives a set of simultaneous equations, which is solved numerically.…”

“…A similar scenario is applicable to the Lorentz force; if the cumulative radial stress due to winding, cool down and Lorentz force exceeds the critical transverse stress, typically +10 MPa, the YBCO-coated conductor is delaminated instantly and thus the coil voltage jumps abruptly, as seen in the coil quenching of low temperature superconducting magnets. [9][10][11][12][13] In the next coil charge, the coil current for the superconducting-normal transition will be significantly reduced.…”

“…Arp [9], Williams and Bobrov [10], and Urata and Maeda [11] [12] demonstrated that coil winding, cool down and Lorentz force result in a radial-stress distribution in a circular coil such as a solenoid or double pancake [13]. The radial stress in a circular coil corresponds to the transverse stress applied to the YBCO-coated conductor.…”

Cryotribology: Development of cryotribological theories and application to cryogenic devices

“…Urata and Maeda, [ 17] on the other hand, examined the radial distribution of conductor-motion-induced quenches in full-scale superconducting solenoids. They used the AE/voltage method to examine the quench behavior of a 24-layer winding.…”

Development of large bore superconducting magnet for wastewater treatment application

“…The superconducting magnet coil is manufactured by dry winding technology, which are frequently used for small-bore and low-field application because of their low manufacturing costs. Stabilities of dry-wound solenoid magnet have been investigated by several authors [10][11][12]. Before the winding process, electrically insulation is made by spraying a layer of 20 microns thick PTFE on the outside of former and the insides of the two end plates.…”