A conduction-cooled, 680-mm-long warm bore, 3-T Nb/sub 3/Sn solenoid for a Cerenkov free electron laser

Author

Wessel, W.A.J. ; den Ouden, A. ; Krooshoop, H.J.G. ; ten Kate, H.H.J. ; Wieland, T. ; van der Slot, P.J.M.

Author_Institution

Low Temp. Div., Twente Univ., Enschede, Netherlands

Volume

9

Issue

2

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

386

Lastpage

389

Abstract

A compact, cryocooler cooled Nb/sub 3/Sn superconducting magnet system for a Cerenkov free electron laser has been designed, fabricated and tested. The magnet is positioned directly behind the electron gun of the laser system. The solenoidal field compresses and guides a tube-shaped 100 A, 500 kV electron beam. A two-stage GM cryocooler, equipped with a first generation ErNi/sub 5/ regenerator, cools the epoxy impregnated solenoid down to the operating temperature of about 7.5 K. This leaves a conservative operational margin for the MJR type of Nb/sub 3/Sn conductor of about 350% (I/sub c/) at 3T. Current leads with HTS sections between the first and second stage of the cryocooler effectively reduce the conductive heat leak. In the warm bore, 60 mm in diameter and 680 mm long, an operational magnetic field of 2 T has been achieved during laser operation without any quench. The field homogeneity is better than 99.5% over 450 mm axial length. Design details and test results of this magnet system are presented.

Keywords

accelerator magnets; cooling; cryostats; electron beams; free electron lasers; laser accessories; niobium alloys; solenoids; superconducting magnets; tin alloys; 100 A; 2 T; 3 T; 450 mm; 500 kV; 60 mm; 680 mm; 7.5 K; Cerenkov free electron laser; ErNi/sub 5/; ErNi/sub 5/ regenerator; HTSC sections; Nb/sub 3/Sn; Nb/sub 3/Sn solenoid; Nb/sub 3/Sn superconducting magnet system; conduction-cooled; conductive heat leak reduction; cryocooler cooled; current leads; epoxy impregnated solenoid; field homogeneity; laser operation; operational magnetic field; solenoidal field; tube-shaped electron beam compression; warm bore; Boring; Electron beams; Free electron lasers; Niobium; Optical design; Solenoids; Superconducting magnets; System testing; Temperature; Tin;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.783316

Filename

783316