Characteristics of anomalously high multiplicity cosmic ray interactions

Six events with the number of secondaries ranging from 250 to several thousands were registered by an installation consisting of a thin graphite target, above and under which are placed photolayers followed by the usual lead X-ray film and emulsion chambers. Data concerning the number of secondaries and their angular distribution are given. The variance of the angular distribution is compared with data obtained at accelerator energies

A technology of drinking water decontamination from radon and its decay products

Underground water is one of the main sources of radon for households. This article focuses on the estimation and removal of radon from underground water using the technology and inorganic sorbents developed by EKSORB Ltd., Russia for liquid radioactive waste treatment in the nuclear power industry. The article presents the results of tests of a system for the removal of radon and radon daughters from water patented by EKSORB. This is achieved by filtering water through RATZIR sorbent, followed by periodic load regeneration. Over a period of three years, the plant is successful in removing radon from the water that had an initial radon content of approximately 1500 Bq/L to less than 60 Bq/L, without releasing radon to indoor/outdoor air. © 2020 Igor Voinov et al., published by Sciendo 2020

Test of nuclear level density inputs for Hauser-Feshbach model calculations

The energy spectra of neutrons, protons, and alpha-particles have been measured from the d+59Co and 3He+58Fe reactions leading to the same compound nucleus, 61$Ni. The experimental cross sections have been compared to Hauser-Feshbach model calculations using different input level density models. None of them have been found to agree with experiment. It manifests the serious problem with available level density parameterizations especially those based on neutron resonance spacings and density of discrete levels. New level densities and corresponding Fermi-gas parameters have been obtained for reaction product nuclei such as 60Ni,60Co, and 57Fe

Review of the some specific features of the detecting of heavy recoils

In this paper, we present the results of the first beam tests of the detection system at the focal plane of the Dubna Gas-Filled Recoil Separator-2 (DGFRS-2), which receives beams from the DC-280 FLNR cyclotron. The high beam intensity of $^{48}$Ca$^{+10}$ heavy ions from the cyclotron enables us to obtain a number of superheavy recoils sufficient to compare both the measured and calculated spectra of superheavy recoils implanted into a silicon detector. A real-time algorithm to search for an Evaporation Residue (ER) -- $\alpha$ correlated sequences is described in brief. It should be noted that the DGFRS-2 spectrometer operates in conjunction with the 48x128 strip DSSD (Double-sided Silicon Strip Detector; 48x226 mm2) detector and a low-pressure pentane-filled gaseous detector (1.2 Torr; 80x230 mm$^2$). A block-diagram of the spectrometer and the event format are also presented. Special attention is paid to the response of a low-pressure pentane-filled DeltaE multiwire proportional chamber for recoils of Fl, synthesized in the $^{242}$Pu+$^{48}$Ca $\to$ $^{287}$Fl +3n complete fusion nuclear reaction. Some actual parameters of the detection system have also been extracted from $^{\rm nat}$Yb + $^{48}$Ca, $^{232}$Th + $^{48}$Ca, $^{243}$Am + $^{48}$Ca, $^{238}$U + $^{48}$Ca reactions. The effect of neighbor strip charge sharing for the ohmic side of the DSSD detector is also under consideration.Comment: 18 page

Partial level density of the n-quasiparticle excitations in the nuclei of the 39< A <201 region

Level density and radiative strength functions are obtained from the analysis of two-step cascades intensities following the thermal neutrons capture. The data on level density are approximated by the sum of the partial level densities corresponding to n quasiparticles excitation. The most probable values of the collective enhancement factor of the level density are found together with the thresholds of the next Cooper nucleons pair breaking. These data allow one to calculate the level density of practically any nucleus in given spin window in the framework of model concepts, taking into account all known nuclear excitation types. The presence of an approximation results discrepancy with theoretical statements specifies the necessity of rather essentially developing the level density models. It also indicates the possibilities to obtain the essentially new information on nucleon correlation functions of the excited nucleus from the experiment.Comment: 29 pages, 8 figures, 2 table