Neutrino detection

The capability of neutralizing daughter ions emitted by a parent atom in nuclear decay would result in practical realization of ULLC for solar neutrino detection, weak interaction physics, cosmochronology, geophysics, environmental research, and other important applications. 

Supernova 1987A tests theory of stellar nucleosynthesis. Neutrinos detected essentially as predicted. 

A pre-requisite for the applicability of this method of analysis is that the dead time for neutrino detection be small. The lower limit for the applicability of this method is determined by the energy range and the dead time of the detection system, and can be worked out from Eq.(1). No clustering on any value of m should be observed below this lower limit, including v... 

The two nearly simultaneous neutrino detections, the Kamiokande II and the IMB data are analyzed. The energy range of the IMB experiment is from 20 to 40 MeV, and the experimental dead time is 0.1 sec. The lower limit for detectability of a mass energy is at least 5 eV. The energy range of the Kamiokande II experiment is from 7.5 MeV to 35 MeV, and the dead time is 50 nano-sec, so that the lower limit of the detectable mass is well below 1 eV ... 

The solar neutrino problem was identified by the first results of Davis et al. using the Cl detector at the Homestake Mine. Davis et al. observed only about one-third of the expected solar neutrino flux as predicted by standard models of the sun, which assume 98.5% of the energy is from the pp chain and 1.5% of the energy is from the CNO cycle. The final result of the Cl detector experiment is that the observed solar neutrino flux is 2.1 + 0.3 SNU compared to the predicted 7.9 + 2.4 SNU, where the solar neutrino unit (SNU) is defined as 10-36 neutrino captures/second/target atom. The GALLEX and SAGE detectors subsequently reported solar neutrino fluxes of 77+10 SNU and 69+13 SNU, which are to be compared to the standard solar model prediction of 127 SNU for the neutrinos detected by these reactions. 

As we discussed, numerous neutrinos are produced by the proton-proton chain in the Sun. However, neutrinos interact only very weakly with matter. Every second over 100 billion neutrinos from the Sun pass through every square inch of our bodies and virtually none of them interact with us. Because neutrinos interact so weakly with matter, detecting them is very difficult. For example, in the first solar neutrino detection experiment, scientist Ray Davis used 100,000 gallons of cleaning fluid (for the chlorine the fluid contained) in a detector located in a South Dakota gold mine. Davis expected to detect on average of 1.8 solar neutrinos per day. Instead, Davis s observed rate has consistently been much lower than this. Also, the long-term rate, plotted as a function of time, shows an anticorrelation between neutrino rate and sunspot activity. 

Table 2. Pre-trapping neutrino detections predicted in SNO (heavy water) and Super Kamioka [99] with hardness ratios up to pm = 24.16 for indicated heavy nuclear e-capture matrix elements for 15 Mq Puller (1982) and 25 Mq WWF presupernova stars. Note the caveat in footnote 20...

A large international collaboration ("Gallex ) is setting up a neutrino detection station in a rock facility in the Mont Blanc. Some Ga atoms in 30 tons of gallium metal is expected to react with solar neutrinos to form Ge (t, 11.4 d) which is to be converted to the gaseous hydride, GeH, and counted in a proportional detector. About 1 atom of Ge formed per day is expected. 

The hydrogen burning in the Sun (4p He -h 2e + 2Ve + Qeff) produces low energy (<20 MeV) electron neutrinos, but the flux ( (Vg) of neutrinos detected fell insistently short of the flux expected. Some of the electron neutrinos produced in the solar core changed flavor. The result, interpreted in this way, is... 

---