Erosion rate study at the Allchar deposit (Macedonia) based on radioactive and stable cosmogenic nuclides (26Al, 36Cl, 3He, and 21Ne)

This paper focuses on constraining the erosion rate in the area of the Allchar Sb-As-Tl-Au deposit (Macedonia). It contains the largest known reserves of lorandite (TlAsS2), which is essential for the LORanditeEXperiment (LOREX), aimed at determining the long-term solar neutrino flux. Because the erosion history of the Allchar area is crucial for the success of LOREX, we applied terrestrial in situ cosmogenic nuclides including both radioactive (26Al and 36Cl) and stable (3He and 21Ne) nuclides in quartz, dolomite/calcite, sanidine, and diopside. The obtained results suggest that there is accordance in the values obtained by applying 26Al, 36Cl, and 21Ne for around 85% of the entire sample collection, with resulting erosion rates varying from several tens of m/Ma to ∼165 m/Ma. The samples from four locations (L-8 CD, L1b/R, L1c/R, and L-4/ADR) give erosion rates between 300 and 400 m/Ma. Although these localities reveal remarkably higher values, which may be explained by burial events that occurred in part of Allchar, the erosion rate estimates mostly in the range between 50 and 100 m/Ma. This range further enables us to estimate the vertical erosion rate values for the two main ore bodies Crven Dol and Centralni Deo. We also estimate that the lower and upper limits of average paleo-depths for the ore body Centralni Deo from 4.3 Ma to the present are 250–290 and 750–790 m, respectively, whereas the upper limit of paleo-depth for the ore body Crven Dol over the same geological age is 860 m. The estimated paleo-depth values allow estimating the relative contributions of 205Pb derived from pp-neutrino and fast cosmic-ray muons, respectively, which is an important prerequisite for the LOREX experiment

Bound -state β- -decay of bare 205 Tl 81+

Beta decay into bound electron states of the daughter atom accompanied by the emission of a monochromatic antineutrino, has been predicted by Daudel et al.[1]. However, a noteworthy probability of βb- decay exists only for highly-charged ions, which makes its observation rather difficult

Determination of Fluorine Ions Penetration Degree Into Enamel by Empa.

Exogen of different preparations was applied to completely healthy teeth of children up to 11 years. A month after application of fluorine, teeth were extracted and prepared by standard methods for investigation by electron microprobe ARL, type SEMQ. The results obtained showed that the highest degree of fluorine ions migration was stimulated by organic fluorite' (amin fluoride). Very poor results were obtained by NaF, while the values obtained by 'fluor-protector' ranges between these two preparates. All up to date investigations showed that protective characteristics of fluorine against caries formation were reached only in case when enamel surface contained fluorine concentration of 10**3, mu g. Thus, our results proved that the first condition for good prophylaxy is obtained by application of aminofluoride and then by 'fluor-protector'

Geochemical Detection of the pp-Neutrino flux with 205Tl LOREX collaboration

An indispensable goal of this proposal still remains the determination of the neutrino capture probability by 205Tl. The ratio 205Pb/205Tl in lorandite provides only the product of solar neutrino flux and neutrino capture probability into the different nuclear states of 205Pb

Status and new data of the geochemical determination pp-neutrino flux by LOREX

LOREX, the acronym of LORandite EXperiment, is the only long-time solar neutrino experiment still actively pursued. It addresses the long-time detection of the solar neutrino flux with the thallium-bearing mineral lorandite, TlAsS2 from the mine of Allchar, FYR Mazedonia, via the neutrino-capture reaction