XXth International Conference on Neutrino Physics and Astrophysics
J.-C.Lanfranchi
Development of Highly Efficient Cryogenic Detectors for GNO
The GALLEX (1991-1997) successor experiment GNO (Gallium Neutrino
Observatory) has been measuring the integral solar neutrino flux
including the dominant flux of the low energy pp-neutrinos since April
1998. With a view to reducing both statistical and systematic errors
in the experiment the miniaturized proportional counters still in use
could be replaced by high resolution cryogenic detectors to measure
the decay of 71-Ge to 71-Ga. The relaxation of 71-Ge occurs via
electron capture under emission of Auger-electrons and X-rays with
energies in the range between 0.16 keV and 10 keV. In order to show
the feasibility of "Cryo-GNO" and to prepare a prototype phase at the
Gran Sasso Underground Laboratory (3600 m.w.e), a new and especially
shielded dilution refrigerator has been set up in the Underground
Laboratory (15 m.w.e) in Garching.