Simultaneous Determination of long-term average Fluxes of CR Muons and Solar pp-Neutrinos

Pavicevic, Milorad and Amthauer, Georg and Anicin, Ivan and Boev, Blazo and Bosch, Fritz and Bruchle, Willy and Djurcic, Z. and Faestermann, Thomas and Henning, Walter and Jelenkovic, Rade and Niedermann, Samuel and Pejovic, Vladan and Vermeesch, P. and Weiss, Achim (2010) Simultaneous Determination of long-term average Fluxes of CR Muons and Solar pp-Neutrinos. In: 22nd European Cosmic Ray Symposium, 3-6 Aug 2010, Turku, Finland.


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The Allchar mine of southern FYR Macedonia contains the world's largest known concentration of thallium bearing minerals. LOREX (acronym for the geochemical LORandite EXperiment) is an international collaboration exploring the opportunity to use the rare mineral lorandite (TlAsS2) for the simultaneous determination of both the average cosmic ray (CR) muon flux and the average pp-solar neutrino flux, over the 4.3 million year age of the deposit. Both fluxes will be determined by counting the extremely small number of atoms of the long-lived 205 Pb present in the mineral, produced by both muons and neutrinos in the reactions with the most abundant stable isotope, 205 Tl. CR muons participate in the reaction 205 Tl(μp,n) 205 Pb, whereas the neutrinos induce the capture reaction 205 Tl(νe,e) 205 Pb*→205 Pb. Assuming a constant solar luminosity and using the currently favoured LMA WSM neutrino oscillation scenario and the estimated neutrino capture cross-section, the expected concentration of neutrinogenic 205 Pb is ~23 atoms per gram of lorandite. In contrast with the production of 205 Pb by solar neutrinos, which is independent of depth, cosmogenic 205 Pb production is strongly depth-dependent and, therefore, very sensitive to the long-term erosion history of the field area. The neutrinogenic 205 Pb component will be estimated by measuring, at the GSI, the total (neutrinogenic + muogenic) 205 Pb concentration at different depths in the Allchar mine, and extrapolating the downwards decreasing trend. The muogenic component is then obtained by subtracting the neutrinogenic, and the small depth-independent background concentration, from the total 205 Pb. The average CR muon flux is henceforth deduced by taking into account the experimentally determined erosion rate at the mining field, while the average solar neutrino flux is obtained from the knowledge of the experimentally determined neutrino capture cross section (to be hopefully measured at the GSI in near future). The best expected resolution of the proposed method is at present of the order of 30% at the 68%CL, i.e. we will be able to detect long-term departures from the modern neutrino and/or fast muon fluxes if they were bigger than 30%. Current status of this complex experiment will be discussed in some detail.

Item Type: Conference or Workshop Item (Paper)
Subjects: Natural sciences > Other natural sciences
Divisions: Faculty of Natural and Technical Sciences
Depositing User: Blazo Boev
Date Deposited: 28 May 2013 10:50
Last Modified: 12 Mar 2015 14:08

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