Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Solar neutrino experiments: Past, present, and future

Conference · · American Astronomical Society, Bulletin; (United States)
OSTI ID:6173504

Solar neutrino detection started 25 years ago by the famous radiochemical chlorine experiment installed by Davis and his collaborators. Neutrinos produce radioactive [sup 37]Ar atoms (T[sub 1/2] = 35 days). Standard solar models (SSM) predict a value between 6.4 and 8 SNU (1 SNU or solar neutrino unit is 10[sup [minus]36] capture/atom/second) and Davis observes 2.3 [plus minus] 0.25 SNU. This reduction by a factor of about 3 is known as the solar neutrino problem. Since 1988 the real time Kamiokande experiment measures a solar neutrino flux also reduced by a factor of about 2(0.49 [+-] 0.04 [+-] 0.06 of SSM predictions). The reaction threshold either in the chlorine (>0.814MeV) or in the Kamiokande (>7.5MeV) experiments is too high to be sensitive to neutrinos produced in the primary pp fusion reaction (E[sub max] = 0.42 MeV). From 1990, a new generation of radiochemical experiments, using gallium as a target (0.233 MeV reaction threshold) started to take data. The first result of SAGE (20[sup +15][sub [minus]20](stat.) [+-] 32(syst.) SNU) has not been confirmed by GALLEX which published, in June 1992, 83 [+-]19 (stat.) [+-] 8 (syst.) SNU (SSM predictions between 124 and 132 SNU). In 1992 SAGE did not confirm its low value using its 1991 data (58[sup +17][sub [minus]24](stat.) [+-] 14(syst.) SNU, preliminary) and its final result should not be too far from the GALLEX one. GALLEX observes about 2/3 of the expected signal, almost 2[sigma] below SSM predictions. This constitutes the first evidence for the pp fusion reaction in the core of the Sun. Interpretations of the flux reductions observed are discussed in terms of astrophysics (reduction of the central temperature of the Sun) or of neutrino oscillations. The future of solar neutrino experiments (Sudbury, SuperKamiokande and Borexino) is briefly presented.

OSTI ID:
6173504
Report Number(s):
CONF-9306217--
Journal Information:
American Astronomical Society, Bulletin; (United States), Journal Name: American Astronomical Society, Bulletin; (United States) Vol. 25:2; ISSN AASBAR; ISSN 0002-7537
Country of Publication:
United States
Language:
English

Similar Records

Low energy solar neutrino experiments: The Soviet American Gallium Experiment (SAGE). Final report, August 12, 1988--October 31, 1994
Technical Report · Fri Mar 31 23:00:00 EST 1995 · OSTI ID:42490
Solar neutrinos observed by GALLEX at Gran Sasso
Conference · Fri Jan 31 23:00:00 EST 1992 · AIP Conference Proceedings (American Institute of Physics); (United States) · OSTI ID:5543903
On solar model solutions to the solar neutrino problem
Journal Article · Mon Aug 15 00:00:00 EDT 1994 · Physical Review, D (Particles Fields); (United States) · OSTI ID:7161202

Related Subjects

661320 -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
662320 -- Neutrino Interactions-- (1992-)
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700360* -- Fusion Reactions-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ARGON 37
ARGON ISOTOPES
ASTROPHYSICS
BETA DECAY RADIOISOTOPES
COOPERATION
DATA
DATA COVARIANCES
DAYS LIVING RADIOISOTOPES
DETECTION
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ELEMENTS
EVEN-ODD NUCLEI
FERMIONS
GALLIUM
HISTORICAL ASPECTS
INFORMATION
INTERLABORATORY COMPARISONS
INTERNATIONAL COOPERATION
ISOTOPES
LEPTONS
LIGHT NUCLEI
MASSLESS PARTICLES
METALS
NEUTRINO DETECTION
NEUTRINO OSCILLATION
NEUTRINOS
NUCLEI
NUMERICAL DATA
RADIATION DETECTION
RADIATIONS
RADIOISOTOPES
SOLAR NEUTRINOS
SOLAR PARTICLES
SOLAR RADIATION
STATISTICAL DATA
STELLAR RADIATION