Results from the Soviet-American gallium experiment

A radiochemical 71Ga-71Ge experiment to determine the primary flux of neutrinos from the Sun began measurements of the solar neutrino flux at the Baksan Neutrino Observatory in 1990. The number of 71Ge atoms extracted from 30 tons of gallium in 1990 and 57 tons in 1991 was measured in twelve runs during the period of January 1990 to December 1991. For the 1990 data, we observed the capture rate to be 20 + 15 -20 (stat) ± 32 (syst) SNU, resulting in a limit of less than 79 SNU (90% CL). This is to be compared with 132 SNU predicted by the Standard Solar Model. The 1991 data, taken with 57 tons of gallium, shows a non zero 71Ge signal. A final result from the 1990 and 1991 data is still pending completion of studies of possible systematic effects. © 1993

The Baksan gallium solar neutrino experiment

A radiochemical 71Ga-71Ge experiment to determine the integral flux of neutrinos from the sun has been constructed at the Baksan Neutrino Observatory in the USSR. Measurements have begun with 30 tonnes of gallium. An additional 30 tonnes of gallium are being installed so as to perform the full experiment with a 60-tonne target. The motivation, experiment procedures, and present status of this experiment are described. © 1990

First results from the Soviet-American gallium experiment

The Soviet-American Gallium Experiment is the first experiment able to measure the dominant flux of low energy p-p solar neutrinos. Four extractions made during January to May 1990 from 30 tons of gallium have been counted and indicate that the flux is consistent with 0 SNU and is less than 72 SNU (68% CL) and less than 138 SNU (95% CL). This is to be compared with the flux of 132 SNU predicted by the Standard Solar Model. © 1991

The Soviet-American gallium experiment at Baksan

A gallium solar neutrino detector is sensitive to the full range of the solar neutrino spectrum, including the low-energy neutrinos from the fundamental proton-proton fusion reaction. If neutrino oscillations in the solar interior are responsible for the suppressed {sup 8}B flux measured by the Homestake {sup 37}Cl experiment and the Kamiokande water Cherenkov detector, then a comparison of the gallium, chlorine, and water results may make possible a determination of the neutrino mass difference and mixing angle. A 30-ton gallium detector is currently operating in the Baksan laboratory in the Soviet Union, with a ratio of expected solar signal to measured background (during the first one to two {sup 71}Ge half lives) of approximately one. 28 refs

Recent results from sage

A radiochemical {sup 71}Ga-{sup 71}Ge experiment to determine the primary flux of neutrinos from the Sun began measurements of the solar neutrino flux at the Baksan Neutrino Observatory in 1990. The number of {sup 71}Ge atoms extracted from initially 30 and later 57 tons of metallic gallium was measured in fifteen runs during the period of January 1990 to May 1992. The observed capture rate is 70{plus_minus}19 (stat){plus_minus}10 (syst) SNU. This is to be compared with 132 SNU predicted by the Standard Solar Model

First Results From the Soviet-American Gallium Experiment

The Soviet-American Gallium Experiment is the first experiment able to measure the dominant flux of low energy p-p solar neutrinos. Four extractions made during January to May 1990 from 30 tons of gallium have been counted and indicate that the flux is consistent with 0 SNU and is less than 72 SNU (68% CL) and less than 138 SNU (95% CL). This is to be compared with the flux of 132 SNU predicted by the Standard Solar Model. 10 refs., 4 figs., 1 tab

Results From the Soviet-American Gallium Experiment

A radiochemical {sup 71}Ga-{sup 71}Ge experiment to determine the primary flux of neutrinos from the Sun has begun operation at the Baksan Neutrino Observatory. The number of {sup 71}Ge atoms extracted from thirty tons of gallium was measured in five runs during the period of January to July 1990. Assuming that the extraction efficiency for {sup 71}Ge atoms produced by solar neutrinos is the same as from natural Ge carrier, we observed the capture rate to be 20 + 15/{minus}20 (stat) {plus minus} 32 (syst) SNU, resulting in a limit of less than 79 SNU (90% CL). This is to be compared with 132 SNU predicted by the Standard Solar Model