Hot Spot in ATLAS Barrel Toroid Quenches

Author

Berriaud, C. ; Juster, F.P. ; Arnaud, M. ; Benoit, Ph ; Broggi, F. ; Deront, L. ; Dudarev, A. ; Foussat, A. ; Humeau, M. ; Junker, S. ; Kopeykin, N. ; Leboeuf, R. ; Mayri, C. ; Olesen, G. ; Pengo, R. ; Ravat, S. ; Rey, J.-M. ; Sbrissa, E. ; Stepanov, V. ;

Author_Institution

CEA, Saclay

Volume

18

Issue

2

fYear

2008

fDate

6/1/2008 12:00:00 AM

Firstpage

1313

Lastpage

1316

Abstract

The ATLAS Barrel Toroid, the largest toroid ever built with 1.1 GJ stored energy, has been successfully tested after installation in the underground cavern in fall 2006. The eight coils of the Barrel Toroid were tested individually before and showed fully acceptable performances. We observed only one training quench during an individual coil test (at 30 A below the maximum test current) and no training during the test of the fully assembled toroid. At currents up to the nominal value of 20.5 kA, the toroid has been quenched inducing normal zones by means of heaters or by stopping the helium flow in the current leads. The quench safety system worked perfectly. Given the safe peak temperatures measured in the cold mass following various quenches, it is concluded that the Barrel Toroid can be operated safely. In this paper, the hot spot of the toroid is presented in detail: the measurement data are compared to various theoretical models.

Keywords

superconducting coils; testing; ATLAS barrel toroid; coil test; energy 1.1 GJ; heaters; helium flow; quench safety system; superconducting coil; Detector magnet; protection; superconducting racetrack coil; testing;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2008.921313

Filename

4510699