H. M. Mittal

Assessment of lung dose from indoor 222Rn and 220Rn exposure in the Jalandhar and Kapurthala districts of Punjab, India

Radon (222Rn) and its progenies are the main source of the inhalation dose received by humans due to natural radioactivity. Residential houses of different villages of Jalandhar and Kapurthala districts of Punjab, India, were chosen for the present study. An attempt has been made to estimate the dose to lung (DRL) due to indoor 222Rn concentration. The results of observed values of dose rate to lung (Dlung), dose to tracheo-bronchial region (DT-B), dose to pulmonary + pulmonary lymph region (DP+PL), dose to lung (DRL) from 222Rn exposure and dose to lung (DTL) from indoor Thoron (220Rn) exposure along with their indoor concentration are summarized in this manuscript. The average value of the measured 222Rn (CR) and 220Rn (CT) concentration in air is 38 and 61 Bq m−3. The value of Dlung varies from 0.76 to 2.52 nGy h−1. The average value of the DT-B, DP+PL and DRL is 1.82, 1.82 and 3.65 nSv, respectively. The average dose received by the lungs from 220Rn exposure is 0.06 µSv. Since the dose in the study area is less than reference level of 10 mSv as recommended by the International Commission on Radiological Protection (ICRP), the studied area is safe from the exposure risk of indoor 222Rn and 220Rn.

Exposure assessment of natural uranium from drinking water

The uranium concentration in the drinking water of the residents of the Jaipur and Ajmer districts of Rajasthan has been measured for exposure assessment. The daily intake of uranium from the drinking water for the residents of the study area is found to vary from 0.4 to 123.9 μg per day. For the average uranium ingestion rate of 35.2 μg per day for a long term exposure period of 60 years, estimations have been made for the retention of uranium in different body organs and its excretion with time using ICRPs biokinetic model of uranium. Radioactive and chemical toxicity of uranium has been reported and discussed in detail in the present manuscript.

Systematic dependence of Grodzins product rule on NpNn

The systematics of the Grodzins product rule (GPR) is studied from the perspective of the valence-proton and neutron product NpNn in the major shell space Z = 50–82, N = 82–126. The variation of nuclear structure from vibrator to deformed rotor is discussed. The Grodzins product shows more dependence on NpNn in the N ≤ 104 region, as it is a region of deformed nuclei. We present here for the first time the dependence of GPR on the NpNn product.

Validity of the single-term formula for ground band energies in light Xe–Gd nuclei

A two-parameter single-term energy formula EJ=aJb is used to study the energy–spin relationship in the ground bands of even–even light Xe–Gd (68≤N≤78) nuclei. This formula works better for soft nuclei as well as for deformed nuclei. We also compared it with other two-parameter formulae, i.e. Ejiri, ab, pq and Brentano et al soft rotor (SRF) formulae. The power index b and the coefficient a are fairly constant, independent of the number of levels for spin J≤12+. The variation of average and with Z, N and with the valence nucleon pair product NpNn is illustrated. Extension of the formula to EJ=aJ(b+cJ) is also tested.

Tests of rigid triaxiality for light Te-Sm nuclei

The experimental data of interband γ-g B(E2) ratios for even-even light Te-Sm nuclei (66 ≤ N ≤ 78) is compared with the predictions of the rigid triaxial model to search for a correlation between the nuclear structure variation with the asymmetry parameter γ0 of the model.

Study of shape phase transitions and the F-spin multiplets through the shape fluctuation energy

The shape fluctuation energy from the cubic polynomial in J for the g-band spectra of even-even nuclei is used to study the constancy of the level structure of the nuclei related to the F-spin multiplets arising in the Interacting Boson Model (IBM). The shape phase transition from the SU(3) to SU(5) or O(6) character of the 21+ state as a function of the total boson number NB and the NpNn product is illustrated for the A = 120-200 region. The relevance of the isotonic and isotopic multiplets in specified regions is supported. A comparison is made with the phenomenological IBM.

Study of multiphonon γγ-band in neutron-rich 112Ru nucleus and molybdenum isotopes

The structure of multiphonon K = 4 γγ-band of , , , and nuclei are investigated using the recently proposed modified soft rotor formula (MSRF). The positive values of the moment of inertia and small values of softness parameter are obtained. The calculated values of moment of inertia of γγ-band are almost equal to the moment of inertia of γ-band, which indeed should be equal to the moment of inertia of ground band. The constant energy parameter EK in the MSRF is also illustrated for K = 4 γγ-band. The staggering pattern in the multiphonon γγ-band is also discussed in detail. The study of one-phonon K = 2 γ-band and two-phonon K = 4 γγ-band using MSRF yields good energy values.

Band moment of inertia of identical SD bands in A = 190 mass region

We propose an approach to describe the band moment of inertia of identical SD bands in A = 190 mass region. We have calculated the band moment of inertia of pair of identical SD bands by using the four-parameter formula and have also investigated its systematics. We observe that the band moment of inertia comes out to be different for two identical SD bands and same for the signature partner SD bands.

Level spins of superdeformed bands in A ∼ 80 mass region

The models variable moment of inertia (VMI), two-parameter (ab) formula and Harris ω2 expansion have been applied to 16 rotational superdeformed bands in the A ∼ 80 mass region to obtain band head spin (I0). The band head spins of these 16 bands in the A ∼ 80 mass region are predicted by least-squares fitting method. Intraband γ-rays energies are fitted in these models to extract model parameters so as to obtain a minimum root mean square (RMS) deviation between calculated and the observed transition energies. The calculated transition energies depend upon the prescribed spins. When a legitimate band head spin is assigned, the calculated transition energies are in good agreement with the observed transition energies.

SYSTEMATIC STUDY OF NUCLEAR SOFTNESS OF SUPERDEFORMED BANDS IN A = 190 MASS REGION

A four parameter formula has been applied to obtain the nuclear softness parameter (σ) for all the superdeformed (SD) bands observed in A = 190 mass region. The nuclear softness parameter values of most of the SD bands are found to be smaller than those of the normal deformed bands, implying more rigidity. The results of this work includes the variation of nuclear softness parameter against the gamma ray energy ratio R(I) = Eγ(I→(I-2))/Eγ((I-2)→(I-4)) of SD bands in A = 190 mass region. The variation of R(I) and the nuclear softness parameter of these SD bands are studied with the product of valence proton and neutron numbers (NpNn). The systematics also includes the variation of σ with the neutron number N. It is also found that the value of softness parameter of signature partner SD bands observed in A = 190 mass region is also the same. We present for the first time the study of softness parameter of SD bands with NpNn scheme.