ETCHED TRACK DETECTORS IN SOLAR-NEUTRINO EXPERIMENTS

Within the framework of LOREX experiment the mineral Lorandite (TlAsS2 ) of the old (5 x 10(6) years) arsenic mine Allchar (Kavadarci, Macedo nia) will be used to estimate average solar neutrino flux from the amo unts of Pb-205 isotope (T1/2 = 1.5 x 10(7) years) induced by Tl-205 (n u(e), e-) Pb-205 reaction. In order to evaluate the amount' of the Pb- 205 isotope induced by Pb-204 (n, gamma) Pb-205 reaction the thermal n eutron flux inside and above the mine was measured by our high sensiti ve etched track neutron dosemeters (CR-39/BE, CR-39/BN-1). The thermal neutron flux was found to be (2.7 +/- 0.4) x 10(-3) cm-2 s-1. In addi tion to cosmic muon interactions and spontaneous fissions the neutrons can be produced through various (alpha, n) reactions due to the high alpha particle flux from the decay chains of uranium and thorium. Ther efore radon concentration in the mine was measured by our diffusion ch amber type dosemeter utilizing CR-39 detector and was found to be 1.5 x 10(4) Bq m-3. The possibilities to extend the application of etched track detectors to another solar neutrino experiments are discussed.