Quench Protection Design and Simulation of a 7 Tesla Superconducting Magnet

Guo, Baoyuan; Ma, Lizhen; Wu, Wei; Yao, Qingxia; Huang, Wen‐Xue; Wu, Xiaolei; He, Yuan; Han, Shiguo; Pan, Yuan

doi:10.1109/tasc.2010.2044783

Cited by 8 publications

(2 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A passive protection system is adopted to protect the superconducting magnet from damage caused by quenching. Cold diodes are laid across the subdivision to reduce both the voltage and temperature of the hot spots [9]. The magnet is assumed to be in an open loop state with an operating current of 180 A.…”

Section: Quench Protectionmentioning

confidence: 99%

Design of a superconducting magnet for CADS

Yang

et al. 2012

Chinese Phys. C

View full text Add to dashboard Cite

This paper describes a superconducting magnet system for the China Accelerator Driven System (CADS). The magnetic field is provided by one main, two bucking and four racetrack coils. The main coil produces a central field of up to 7 T and the effective length is more than 140 mm, the two bucking coils can shield most of the fringe field, and the four racetrack superconducting coils produce the steering magnetic field. Its leakage field in the cavity zone is about 5 × 10−5 T when the shielding material Niobium and cryogenic permalloy are used as the Meissner shielding and passive shielding respectively. The quench calculations and protection system are also discussed.

show abstract

Section: Quench Protectionmentioning

confidence: 99%

Design of a superconducting magnet for CADS

Yang

et al. 2012

Chinese Phys. C

View full text Add to dashboard Cite

show abstract

“…The back-to-back cold diode configuration eliminates the risk of unidirectional connection of the magnet power supply. Various types of cold diodes have been extensively used for subdivisions of multi-coil superconducting magnets for high-energy particle accelerators or MRI scanners [4][5][6][7][8][9][10][11][12]. The back-to-back cold diode assemblies (DA-1 and DA-2, as shown in figure 1) across each subdivision ensure the bypassing of the operating current through the cold diodes if the voltage across each subdivision (SD-1 or SD-2) of the magnet exceeds the resultant forward voltage or the threshold voltage (hereinafter 'turn-on' voltage) of each diode assembly during a quench of the MRI magnet.…”

Section: Introductionmentioning

confidence: 99%

High-power cold diodes for the protection of a 1.5 T superconducting MRI magnet system

Soni¹,

Gupta²,

Kar³

2022

Semicond. Sci. Technol.

View full text Add to dashboard Cite

The cold diodes play a crucial role in the various operational aspects of the superconducting magnet of an MRI scanner. The forward and reverse characteristics, failure modes are studied for two types of high-power rectifier diodes to find their suitability of application at 4.2 K in a whole-body 1.5 T superconducting MRI magnet system.The diodes are characterized at various temperatures ( 300 K, 77 K and 4.2 K) in the current range up to 600 A. The turn-on voltage of the diodes at 4.2 K is found to be increased by 7-12 times that of the room temperature. The diodes show negative differential resistance beyond 1 A of forward current at 4.2 K . The forward voltage stabilizes in the ranges of 1.22 -1.24 V after attaining the turn-on voltage in the range of 5-8 V. The significance of negative differential resistance has been analyzed for the MRI magnet. The long-term stability of the forward voltage has been studied at 77 K with 550 A of the forward current. Two modes of the failure of the diodes are also studied to foresee any failure during the operation of the magnet.

show abstract