[en] Mass fragmentation potentials for the radioisotopes ²²²Ra and ²²³Ra are calculated. They show that shell effects determine all the exit channels and the proximity potential help the emission of ¹⁴C and other lighter clusters in the radioactive decay of²²²Ra and ²²³Ra. (M.G.B.)

[en] This work analyses the α decay properties of actinides. Geiger–Nuttall plots are presented for actinides. The competition between α decay and spontaneous fission have been studied and the dominant decay mode have been identified. The results have been compared with experiments and they agree well with those of the experiments

[en] One of the simple and effective methods of removing ²²²Rn and ²²⁰Rn in the occupational domain of uranium mills and thorium processing facilities is based on the adsorption on activated carbon, which is easily available in India. However, for the large scale use of charcoal, it is necessary to study its ²²²Rn and ²²⁰Rn adsorption characteristics. Interestingly, adsorption coefficient (K) of various types of charcoal materials have been found to vary by a factor of more than ten depending upon the type of charcoal, environmental and experimental conditions. Adsorption coefficient plays a central role in determining the breakthrough time, which is the time after which a stable gas or a long lived species such as ²²²Rn, emerges at the downstream end of the adsorber system. The paper is aimed at generation of ²²²Rn breakthrough curves and estimation of breakthrough time (τ) for activated charcoal adsorption beds of different dimensions, and estimation of K values from the breakthrough curves, and evaluation of the dependence of K values with the flow rate of the carrier gas and pressure across the adsorber bed

[en] The effects of residual coupling interactions on the newly discovered decay ²²²Ra→ ¹⁴C+ ²⁰⁸Pb are investigated. The couplings to the low-lying collective excitations of ²⁰⁸Pb produce an order of magnitude enhancement in the tunneling probability. A new possible mechanism for this decay is discussed whereby a ¹²C fragment is transformed into ¹⁴C by picking up two neutrons as it tunnels out

[en] Radon is ubiquitous in nature. The immediate source of Radon is "2"2"6Ra is present in building materials underneath earth due to presence of natural uranium in terrestrial region. "2"2"2Ra gas continuously diffused out into room atmosphere through the pores, cracks and fissures if any. The buildup of this "2"2"2Rn is anticipated in a closed room lack of proper ventilation. A study was done to see the build up pattern of radon concentration by two different measurement techniques in a closed room of ESL, Jaduguda. Present paper summarizes the result of buildup study of "2"2"2Rn in a closed room of lab for a period of 3 months

[en] The problem of exposure to radon indoor is the subject of many scientific investigations, since the radiation absorbed by human bodies might be the cause of tumours or leukaemia. In almost all Countries, sampling campaigns of ²²²Rn have been started with the purpose of monitoring its distribution and evaluating exposure risk levels. The radon is a gas that diffuses in the soil and penetrates into the buildings following multiple pathways. Indeed, many factors influence its migration, both of geological and atmospheric nature, and even anthropic. Therefore, it is evident that the presence of radon in the environment belongs to that class of complex phenomena that has originated the research on fractals. The possibility of modelling natural phenomena by means of fractals has recently been improved introducing the concept of multifractals, studying the fractal properties shown by the different intensity levels of a phenomenon (e.g., analysing the different fractal features of increasing concentrations of radon). In our case, given the complexity of the radon diffusion process, we shall adopt the stochastic formalism of Universal Multifractals, as introduced by Schertzer and Lovejoy

[en] Studies have been conducted on the radiation effects in the uranium mining sites across the globe to identify the potential risk to the common public due to the environmental nuclear radiation at uranium site and its surrounding areas. Atomic Minerals Directorate for Exploration and Research (AMDER), Hyderabad has documented the presence of uranium near the Chitrial village of Nalgonda district, Telagana State and proposed for uranium exploration. Therefore, a pre-operational study of environmental radiation levels is useful to establish a base line data before uranium mining activity comes into existence in the area and surroundings. Radium (²²²Ra) and Thoron (²²⁰Rn) are the decay products of radium-226 and radium-224. Radon and thoron are responsible for about half of the radiation dose received by general population. In view of the above, the present study has been carried out in the village (Dasarlapally) which is about 2.5 km from the proposed uranium exploration site. To study the airborne radioactivity levels, pin-hole dosimeters with SSNTDs were deployed in the different types of dwellings chosen randomly. The preliminary measured average concentrations of radon and thoron (two quarters) in the study area are found to be 136 ± 42 and 129 ± 91 Bq/m^-3 and the variation of radon and thoron concentration in the different types of dwellings are presented in this paper. (author)

[en] The main shortcoming with the procedure to determine ²²⁶Ra in a gamma spectrum of an environmental sample by means of the ²¹⁴Bi and ²¹⁴Pb photopeaks is the likelihood of ²²²Rn leakage from the sample counting vial. An option to make such determination is to disregard the ²²⁶Ra gamma-contributions to the spectrum, other than 186.2 keV (3.5%), subtracting the ²³⁵U contribution to the ²²⁶Ra+²³⁵U peak at 186 keV. The use of this option to determine directly ²²⁶Ra activity concentrations in environmental samples and in NORM/TENORM matrices will be presented and discussed. (author)

[en] The ²³⁰U decay chain has been investigated using Ge(Li) spectrometers in singles and coincidence measurements. The internal-conversion spectra have been studied in a β-spectrometer with a Si(Li) detector placed in a homogeneous magnetic field. A total of 31 γ-ray transitions, 14 of which have not been reported before, have been observed in the decay of ²³⁰U and its descendants. All transitions could be unambiguously placed in the individual level schemes. The new band-heads at 805 and 914 keV in ²²⁶Th and ²²²Ra, respectively, are proposed as 0⁺ quadrupole-pairing vibrations. No evidence has been found for the existence of 0⁺ two-phonon harmonic octupole states in these nuclei. A possible anharmonicity of the octupole vibrations is discussed. (Auth.)

[en] A method is developed for the determination of radium-226, based on the measurement of the amount of radium-222, extracted from the substance being analyzed. The limit of detection of radium, equal to 6.6 X 10^-15 mass%, is achieved because of the use of a low-background proportional counter and a special vacuum facility for filling the detector with the working gas mixture