Title :
Low-background 3He proportional counters for use in the Sudbury neutrino observatory
Author :
Browne, M.C. ; Bowles, T.J. ; Brice, S.J. ; Doe, P.J. ; Duba, C.A. ; Elliott, S.R. ; Esch, E.I. ; Fowler, M.M. ; Germani, J.V. ; Goldschmidt, A. ; Heeger, K.M. ; Hime, A. ; Lesko, K.T. ; Miller, G.G. ; Ollerhead, R.W. ; Poon, A.W.P. ; Robertson, R.G.H. ;
Author_Institution :
Nucl. Phys. Lab., Washington Univ., Seattle, WA, USA
fDate :
8/1/1999 12:00:00 AM
Abstract :
Current solar neutrino detectors measure a considerably lower flux of electron-flavor neutrinos than predicted by solar models. This could be an indication of neutrino oscillations, which would provide direct evidence that neutrinos have mass. The Sudbury Neutrino Observatory (SNO) was designed to detect all flavors of neutrinos, and will provide a rigorous test of this theory. The SNO detector´s heavy water target gives it the unique ability to detect all non-sterile neutrino flavors via the neutral-current (NC) break-up of the deuteron. This NC interaction liberates a neutron which may be detected with an array of discrete 3He proportional counters. The strict radioactivity requirements imposed by the need for low backgrounds dictate the use of ultra-pure materials and processes in building these counters. Additionally, they must survive in the heavy water environment for several years. The design, construction, and testing of these unique counters are described
Keywords :
cosmic ray apparatus; helium-3 counters; neutrino detection; He; Sudbury neutrino observatory; discrete 3He proportional counters; electron-flavor neutrinos; heavy water environment; low-background 3He proportional counters; neutral-current break-up; neutrino oscillations; radioactivity requirements; solar neutrino detectors; ultra-pure materials; Counting circuits; Current measurement; Detectors; Helium; Neutrino sources; Neutrons; Observatories; Predictive models; Radioactive materials; Testing;
Journal_Title :
Nuclear Science, IEEE Transactions on
