Search Menu
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information
Search Scholarly Publications

Title: Quench-Back Management for Fast Decaying Currents in SHMS Superconducting Magnets at Jefferson Lab

Journal Article · · IEEE Transactions on Applied Superconductivity
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [1]; ORCiD logo [1]
  1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
+ Show Author Affiliations

The Super High Momentum Spectrometer (SHMS) of Hall C, part of the 12-GeV upgrade at Jefferson Lab, was successfully commissioned in 2017. Early operation demonstrated that fast current dumps decays of the SHMS Q2/Q3 and dipole superconducting magnets triggered quenches, causing some level of operational difficulty. Tests and detailed assessments suggest that nonquench induced fast current decay could result in substantial ac loss in the conductor and subsequently trigger a quench-back effect. The OPERA/ELECTRA software package was used to calculate the amount of heat deposited in the copper stabilizer from a fast current decay. The resistances of external energy dump resistors were lowered to slow the fast dumping of the magnet's current to reduce or eliminate the quench-back effect. A worst-case adiabatic quench scenario was analyzed, assuming no external dump resistor and no liquid helium surrounding the coil, to ensure the safety of the magnets. The stress levels in the coil imposed by winding, collaring preload, Lorentz force, and temperature gradient during a quench were also examined. The Tsai-Wu material failure criterion was used to determine the acceptable combined stress level. Linear orthotropic analysis of the coil indicates that the magnets can be operated safely with appropriately sized dump resistors. Fast dump tests with the modified dump resistors have been planned to verify the performance and suitability.

Research Organization:
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC05-06OR23177
OSTI ID:
1561084
Report Number(s):
JLAB-PHY-19-2903; DOE/OR/23177-4772; TRN: US2000589
Journal Information:
IEEE Transactions on Applied Superconductivity, Vol. 30, Issue 3; ISSN 1051-8223
Publisher:
Institute of Electrical and Electronics Engineers (IEEE)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 5 works
Citation information provided by
Web of Science

Figures / Tables (30)

Fig. 1(p. 1)figure Fig. 1
TABLE I(p. 1)table TABLE I
Fig. 2(p. 2)figure Fig. 2
Fig. 3(p. 2)figure Fig. 3
Fig. 4(p. 3)figure Fig. 4
Fig. 5(p. 3)figure Fig. 5
Fig. 6(p. 3)figure Fig. 6
Fig. 7(p. 4)figure Fig. 7
TABLE II(p. 4)table TABLE II
Fig. 8(p. 5)figure Fig. 8
Fig. 9(p. 5)figure Fig. 9
TABLE III(p. 5)table TABLE III
Fig. 10(p. 6)figure Fig. 10
TABLE IV(p. 6)table TABLE IV
TABLE V(p. 6)table TABLE V
TABLE VI(p. 6)table TABLE VI
Fig. 11(p. 7)figure Fig. 11
Fig. 12(p. 7)figure Fig. 12
Fig. 13(p. 7)figure Fig. 13
Fig. 14(p. 7)figure Fig. 14
Fig. 15(p. 8)figure Fig. 15
Fig. 16(p. 8)figure Fig. 16
TABLE VII(p. 8)table TABLE VII
TABLE VIII(p. 8)table TABLE VIII
Fig. 17(p. 9)figure Fig. 17
Fig. 18(p. 9)figure Fig. 18
TABLE IX(p. 9)table TABLE IX
Fig. 19(p. 10)figure Fig. 19
TABLE X(p. 10)table TABLE X
TABLE XI(p. 10)table TABLE XI

Similar Records

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AC loss
dump resistor
fast discharge
magnet
quench back
superconducting
Tsai-Wu criterion