Speaker
Description
Existing chemical procedures are characterized by ambiguity in determining the content of rhenium due to competing manifestations of other elements. There is a need to develop independent methods for the analysis of rhenium-containing rocks. The complexity of this analysis also lies in the presence of naturally radioactive elements in the samples.
The composition and content of non-radioactive elements in ore samples of the Briketno-Zheltukhinskoe U-Mo-Re deposit [1] were determined using neutron activation analysis. Rock samples were irradiated by neutron flux of the IN-LUE photoneutron source of INR RAS [2].
Measurements of the samples activity were carried out using a low-background gamma-ray spectrometer [3], which included a high purity germanium (HPGe) detector placed in a low-background chamber with "passive" protection. The use of such spectrometer allows comparative measurements of both gamma spectra of natural radioactivity of samples and their activation spectra.
A comparative analysis of these spectra showed that in the range up to 200 keV they have a simple form. In the activation spectra, there are several noticeable peaks corresponding to short-lived ($^{188m}$Re, 18.6 min) and long-lived ($^{186}$Re, 89 h; $^{188}$Re, 17 h) rhenium isotopes that do not overlap with background peaks and peaks from other elements. The peak corresponding to the 155 keV state of $^{188}$Re with a half-life of 17 hours should be considered as the most convenient for analytical purposes.
An analysis of activation gamma spectra indicates the possibility of an unambiguous determination of rhenium against the background of accompanying elements, which makes the neutron activation analysis acceptable for determining the rhenium content.
The reported study was funded by RFBR, project number 19-35-90095.
- I.V.Vikentyev, P.E.Kailachakov // Lithol. Miner. Res. 2020. V. 55(3). P. 1-18.
- A.V.Andreev et al. // Bull. Russ. Acad. Sci.: Phys. 2017. V. 81. P. 748.
- A.V.Andreev et al. // Nucl. Phys. Eng. 2013. V.4. P. 879.
