Effects of non-parallel magnetic fields on hexagonal cell drift chambers

Author

Mestayer, M.D. ; Tam, C.L. ; Wang, K. ; Baghaei, H. ; Christo, S. ; Dytman, S.A. ; Gilfoyle, G.P. ; Hewitt, J.D. ; Hersman, F.W. ; Hicks, R.S. ; Miskimen, R.A. ; Schumacher, R. ; Vineyard, M.F.

Author_Institution

CEBAF, Newport News, VA, USA

fYear

1991

fDate

2-9 Nov. 1991

Firstpage

462

Abstract

The effect of magnetic field on drift velocity was measured in a wire chamber with an hexagonal cell geometry and an argon-ethane (50:50 by weight) gas mixture. The CLAS (CEBAF large acceptance spectrometer) prototype drift chamber was tested in a magnetic field using cosmic rays. The drift time to distance correlation was studied as a function of magnetic field strength using cosmic ray tracks. Particular attention was paid to the corrections due to differing track entrance angles and differing angles of the magnetic field direction with respect to the wire axis. Spatial resolutions better than 190 mu m were achieved for field strengths up to 1.5 T and angles between wire and field direction ranging from 0 degrees to 30 degrees . An argon-ethane mixture diluted with 60% helium showed less sensitivity to magnetic field effects, and only slightly worse resolution.<>

Keywords

magnetic field effects; position sensitive particle detectors; proportional counters; 1.5 T; Ar; Ar ethane mixture; Ar-He; CLAS; drift velocity; hexagonal cell drift chambers; magnetic field strength; nonparallel magnetic field effects; spatial resolution; wire chamber; Cosmic rays; Electron mobility; Geometry; Magnetic field measurement; Prototypes; Spatial resolution; Spectroscopy; Testing; Velocity measurement; Wire;

fLanguage

English

Publisher

ieee

Conference_Titel

Nuclear Science Symposium and Medical Imaging Conference, 1991., Conference Record of the 1991 IEEE

Conference_Location

Santa Fe, NM, USA

Print_ISBN

0-7803-0513-2

Type

conf

DOI

10.1109/NSSMIC.1991.258934

Filename

258934