An Apparatus to Control and Monitor the Para-D2 Concentration in a Solid Deuterium, Superthermal Source of Ultra-cold Neutrons

Controlling and measuring the concentration of para-D2 is an essential step toward realizing solid deuterium as an intense ultra-cold neutron (UCN) source. To this end, we implemented an experimental technique to convert para- to ortho-deuterium molecules by flowing D2 gas through a cryogenic cell filled with paramagnetic hydrous ferric oxide granules. This process efficiently reduced the para-D2 concentration from 33.3% to 1.5%. Rotational Raman spectroscopy was applied to measure the residual para-D2 contamination to better than 2 parts in 10^3, and the hydrogen contamination to 1 part in 10^3. We also contrast our optical technique to conventional thermal conductivity measurements of the para-D2 concentration, reporting some of the relevant strengths and weaknesses of our implementation of each technique.Comment: accepted for publication in NIM

Species composition of terrestrial vertebrates in the zone of potential impact of the Nizhneboguchanskaya Hydro Electric Power reservoir

The analysis of the species richness and landscape positioning of terrestrial vertebrate animal communities in the territory of the potential impact of the reservoir of the planned Nizhneboguchanskaya Hydro Electric Power station (HEP) was carried out. The studies were conducted in the main animal habitats according to standard methods, from 2021 to 2022. The vertebrate fauna in the flooding zone and the potential impact of the projected reservoir of the Nizhneboguchanskaya HEP includes 250 species, including 56 species of mammals, 187 species of birds, 3 species of reptiles and 4 species of amphibians. There are eight main types of biotopes was identified: dark coniferous, light coniferous, mixed and small-leaved forests, wetland complexes, meadows and rocky outcrops. A comparative analysis of faunal richness was performed for each biotope type. The study showed that the highest species diversity is observed in forest habitat: from 126 to 155 species. Of these, the highest faunal diversity is inherent in communities of mixed forests, which is post-fire and after cutting long-derivatives of coniferous forests. Also, in different forest biogeocenoses, there is a high similarity in the species composition of terrestrial vertebrates. The most specific fauna compositions have rocky outcrops, wetlands and meadows, when compared with each other and, especially, with forest biocenoses. As a rule, these habitats are critical for the survival of a number of species, some of which are protected. The preservation of these habitats during the construction and operation of the Nizhneboguchanskaya HEP reservoir will require special attention to maintain the natural level of species diversity of terrestrial vertebrates