Investigation for Suitable Target-Projectile combination for Fusion from the Isotopes of Ti and Nd using Intrinsic Fusion and Fission Barriers Analysis

Background: A configuration is most suitable for the fusion if it corresponds to a minimum intrinsic fusion barrier and maximum fission barrier.Purpose: To find a suitable target-projectile combination from the isotopes of Ti and Nd by analyzing the intrinsic fusion and fission barriers theoretically by including the deformations up to hexadecapole order.Methods: The fragmentation theory has been used for the calculations. Results: The intrinsic fusion barrier is minimum and fission barrier is maximum for the targetprojectile combination: 43Ti+150Nd in belly-belly configuration, and the inclusion of deformation of higher order leads to the decrease of fission barrier for the prolate shaped cases and compactness for most of the cases.Conclusions: The most suitable target-projectile combination from the isotopes of Ti and Nd for the fusion is 43Ti+150Nd

Radii of Thorium Nuclides Lying in Between the Drip Lines

Background: Nuclear rms radii give information about the nuclear structure, nuclear shape, deformation etc. Microscopic methods are widely used for the study of nuclear structure properties. Hartree-Fock method with an effective interaction of Skyrme force is used for studying the nuclear structure properties.Purpose: To calculate the rms radii of proton and neutron for thorium nuclei, lying between the drip lines, by using the microscopic mean field theory. The nuclear rms radii data is useful for identifying the shape variation of thorium nuclei, from proton drip line to neutron drip line. It also helps to identify the trends in nuclear radii variation as we move towards the drip line. This nuclear data will be useful in designing experiments in future and also in understanding the behaviour of complex nuclei. Microscopic study of thorium nuclei is also important in the astrophysical environments.Methods: This study is based on the Skyrme interacting potential in the Hartree-Fock mean field theory. Iterative diagonalization method with the help of a computational code is used for solving the Hartree-Fock equation.Results: We have calculated the rms radii of neutron, proton and their total with SV, SLY4 and UDF2 parametrization of the Skyrme force. Neutron rms radii, proton rms radii and total rms radii of thorium nuclei are found to increase with neutron number. UDF2 parametrization shows an oscillatory nature in the rms radii. This may be due to the shape change of thorium nuclei when adding neutrons.Conclusions: The rms radii of thorium nuclei are found to increase with neutron number. The Skyrme force with UDF2 parametrization is the most suitable one for the structure studies of thorium nuclei

Charge Radius And Neutron Skin Thickness Of Platinum And Osmium Isotopes Near The Nuclear Drip Lines

Background: The density distributions of exotic nuclei are different from that of stable nuclei. For stable nuclei, charge radii can be obtained through electron scattering experiments. The excessive neutrons in neutron-rich nuclei make a decoupling of neutron and proton distribution and as a result nuclear skin structures are appeared.Purpose: The charge radius and the way by which nucleons are distributed can provide information about size, surface thickness and shell structure of nuclei. The information collected from such nuclei can be used for astrophysical studies to understand the origin of heavy elements. Methods: In the present study, we have made an attempt to investigate the charge radii, rms radii and skin thickness of Pt and Os isotopes. Here, the calculations were made by using the HFB solver which utilizes HO single-particle basis and iteratively diagonalizes the HFB Hamiltonian based on the Skyrme forces.Results: Here we can observe an increase in charge radius, rms radius and skin thickness with neutron number. The charge radii calculated are in good agreement with the experimental data and predictions of RCHB model. A linear dependence of skin thickness on neutron number is observed with the change in slope is noticed around N =126.Conclusion: Using HFB theory, we have analyzed the charge radius and neutron skin thickness of Pt and Os isotopes. The drip line nuclei have larger charge radius in comparison to the stable nuclei. The redistribution of the nucleons due to addition of neutrons leads to the gradual increase in neutron skin. The sudden increase of skin thickness may be due to the extra stability and shell closure around the magic number

Evaluation of Natural Radioactivity Levels and Exhalation rate of 222Rn and 220Rn in the Soil Samples from the Kuthiran Hills, Kerala, India

Background: Exposure to radon and its decay products is one of the important contributors of radiation doses to human population. Radon exhalation study is important for understanding the contribution of the soil towards the total radioactivity concentration found inside the dwellings. Purpose: The aim of the present study is to investigate the radioactivity levels and radium and radon exhalation rates in soil samples collected from Kuthiran hills and nearby places in Thrissur district, Kerala state, India. On the basis of this data, radiological health hazard parameters are also evaluated. Methods: About 18 soil samples were collected from the study location. The radium, thorium and potassium activity concentrations were analyzed by HPGe gamma ray spectrometer. The “can technique” using LR-115 type II plastic track detectors have been used for the measurement of radon exhalation rate in soil samples. Results: The mean values of activity concentrations of 226Ra, 232Th and 40K were 64.60 Bqkg-1, 109.03 Bqkg-1and 972.67 Bqkg-1 respectively. The mean value of radon mass exhalation rate is 9.19 mBqkg-1h-1 and thoron surface exhalation rate is and 237.9 mBqm-2s-1. The radium equivalent activity concentration of all the soil samples was below the level of 370 Bqkg-1, recommended for building materials, by OECD 1979 (Organization for Economic Cooperation and Development). Conclusions: The results show that the study area is safe, as far as the health hazard effects of radium and radon exhalation rate are concerned. This data will be helpful in establishing new regulations and safety limits, related to the radiation dose and radon activity in Kuthiran hills

Study of negative parity Bands in 136 Ce

Background: The band structures of Ce(Z=58) nuclei with A~135 were studied extensively with the physics interest such as triaxiality and rotation like-sequence i.e. shears mechanism etc. The level structures of 136Ce, with 58 protons and 78 neutrons, were predicted to arise from the interaction between valence proton particles above the Z = 50 major shell and four neutron holes in the N = 82 major shell. The γ-ray spectroscopy of 136Ce was performed here for experimental investigations.Purpose: Study the states of two negative parity bands B1 and B2 with band head Iπ = 5- andIπ = 6- with level energy 1979 keV and 2425 keV respectively. Methods: The excited states of 136Ce are populated via the 124Sn(16O, 4n ) 136Ce fusion evaporation reaction at Ebeam = 90 MeV. The emitted γ-rays from the excited nuclei were detected using the Indian National Gamma Array (INGA) spectrometer at IUAC, New Delhi India.Results: States of two negative parity bands, with band-head Iπ = 5- state at 1979 keV and Iπ = 6- state at 2425 keV have been studied in the present work. The placement of γ-ray transitions of negative parity band B1 has been changed from the earlier reported work and hence the level energy of this band revised and the systematics study of negative parity bands of isotones with N=78, the 136Ce, 134Ba, 138Nd has been carried out.Conclusions: The 806.3 keV γ-ray is found altered with the placement of 971 keV γ-ray transition in the earlier reported work and a 1015.2 keV γ-ray transition is placed in the place of the previously reported 1013 keV γ-ray transition above Iπ = 11- state in band B1. Previously, B1 and B2 bands were predicted as signature partner bands associated with two-quasiparticle, ν[h11/2⊗s1/2/d3/2] configuration. The present work does not support these bands as signature partner bands. Present results are discussed in view of systematics

Low Energy S-Wave Proton-Deuteron Scattering Phase-Shifts using Morse Potential

Background: Study of nucleon-nucleus interaction is important to understand the stabilityof nuclei. At small lab energies ≈ 1-10 MeV, the three body 3He system can be considered asa combination of proton and deuteron two body system. The two body system can be modeled by a local central potential along with Coulomb potential to obtain phase-shifts.Purpose: Molecular Morse potential has been successfully able to calculate scattering phaseshifts of neutron-Deuteron (3He). The main objective of this paper is to test if Morse potential proves to be a good interaction potential to study proton-Deuteron (3He) scattering as well. Methods: The phase function method is solved numerically using RK-5 method for determining the S-wave scattering phase shifts (SPS) for proton-deuteron (p-D) scattering as afunction of proton laboratory energy ranging from 1-10.4 MeV. The model paramters of Morse potential have been varied to obtain best mean absolute percentage error (MAPE) w.r.t. experimental data.Results: The calculated SPS are found to have MAPE less than 3 percent w.r.t experimental phase shifts. Partial scattering cross-section has been determined using the obtained SPS.Conclusions: Morse potential has been found to be successful in explaining interactionbetween proton and deuteron

A Hartree-Fock-Bogoliubov Study on the Pairing Correlations of the Isotopes of Cobalt

Background: The phenomena of nucleon pairing could be outlined from the Bethe-Weizäcker semi-empirical formula, from which the nuclear properties, viz. the binding energy, stability, shape etc. could be clearly sketched. Though the pairing correlation seems to be a small correction to the binding energy term, it plays a determinative role in defining the structure of nuclear systems. The addition to the binding energy in turn affects the position of the isotope on the dripline and hence increases the stability. Purpose: To study the effects of pairing on the ground state properties of the isotopes of Cobalt. Methods: We use Hartree-Fock-Bogoliubov (HFB) theory for the study. The general wave functions for the HFB approach are determined from variational principle. The eigen functions for the Hamiltonian are connected with the particle operators through the Bogoliubov transformations. The Hartree-Fock energy is obtained through the minimization of the variational parameter and the HFB equation is solved by iterative diagonalization by restoring the particle number symmetry. Results: The HFB analysis substantiates the effect of pairing correlation on binding energies, neutron and proton pairing energies, neutron and proton pairing gaps and one- and two-neutron separation energies of the Cobalt isotopes. The binding energies and one and two-neutron separation energies match with the experimental values and for pairing energies and pairing gaps, the regions where pairing is significant and the effects of shell closure at the vicinity of magic configuration of neutrons could be recognized. Conclusion: The Hartree-Fock-Bogoliubov calculations of the effects of pairing could be used as an efficient tool to study the nuclear structure. It can be ascertained that pairing plays an important role in determining the ground state properties of atomic nuclei

Deformation Effect on Proton Bubble Structure in N = 28 Isotones

Purpose: To study the effect of nuclear deformation on proton bubble structure of N = 28 isotones and and compare it with the spherical limits. The reduction of depletion fraction due to deformation can be explained by studying the relative differences in the central densities.Methods: In this work, we have employed relativistic Hartree-Bogoliubov (RHB) model withdensity-dependent meson-exchange (DD-ME2) interaction and separable pairing interaction. We have performed axially constrained calculations to investigate the deformed proton bubble structure in 40Mg, 42Si, 44S, and 46Ar, isotones of N = 28 shell closure.Results: We have observed that the nuclear deformation play againsts the formation of bubble structure. In the spherical limits, the isotones of N = 28 shell closure have pronounced bubble structure with large value of depletion fraction. But, the increase in deformation leads to the disappearance of bubble structure. The internal densities in deformed nuclei are found to increase with deformation which can be related to the decrease in depletion fraction.Conclusion: By using RHB model, we have investigated the ground state and proton bubble structure of N = 28 isotones. In 44S, and 46Ar, the 2s1/21d3/2 states get inverted due to the weakning of spin-orbit strength. Due to strong dynamical correlations, arising from deformation, the central depletion of proton density is greatly affected in these isotones. The decrease in depletion fraction can be related to increase in the internal density due to deformatio

Hydrochemistry and Uranium Concentration in Brackish Groundwater from an Arid Zone, Chihuahua, Mexico

In arid zones, the principal water supply is from groundwater, which can present high concentration of salts, heavy metals, and radioactive elements. The aim of the study was to determine isotopic uranium concentration in groundwater samples with high concentration of salts and its association with other chemical species. Samples were taken from wells with high salt content. The 238,234U radioisotope concentrations were determined by liquid scintillation and alpha-particle spectrometry. In addition, the physical-chemical parameters were recorded in situ; whereas the dissolved ions and elemental composition were measured by UV-Vis and X-ray fluorescence spectrophotometry, respectively. To obtain isotopic uranium concentrations, three radiochemistry procedures were carried out. An ANOVA test was performed to compare the results from procedures, as well as an analysis of Pearson correlation was used between parameters to obtain their associations. Statistically, the U isotopic concentrations did not show differences (p-value 0.82) between procedures. 238U and 234U showed mean concentrations of 6.7 mBq mL-1 and 16.6 mBq mL-1, respectively, with an Activity Ratioby up 7.2. The groundwater under study showed high concentration of TDS, calcium, sulphate, chloride, nitrate, and nitrite. Isotopic U concentrations tend to increase with NO3>Zn>Cl>Br>SO4>Cu>T>SDT>P; meanwhile their contents decrease with T>Cl->NO2>Fe. These findings help us to understand the uranium behavior in groundwater with high salt contents as well as the influence of agricultural supplies on chemical species presents in groundwater

Structural Shielding Design of CT Facility using Monte Carlo Simulation

Radiation application in medicine offers extraordinary benefits. But radiation is like a double-edged sword, it has both benefits and associated risks on the community in contact. To justify the safety of workers and members of the public, regulated use of radiation is assessed by the radiation protection protocols. The aim of this study is to design a Computed Tomography (CT) facility with a simplified model of CT scanner, whose shielding follows the guidelines of National Council on Radiation Protection and Measurements (NCRP) Report No. 147. To design the study model, Monte Carlo (MC) radiation transport code in MCNPX 2.6.0 was used for the simulation. Furthermore, MCNPX was used to measure the photon flux in a vicinity or the detector cell. To validate the functioning of the X-ray tube, the experimental results were compared with the X-ray Transition Energies Database of National Institute of Standards and Technology, U.S. Department of Commerce. The results obtained were within 0.60% of relative error. To confirm the functioning of shielding design, radiation protection quantity, air kerma was measured at several points outside, and inside of the CT room and they were under the radiation dose recommended by NCRP, which demonstrates that the shielding design wassuccessful in blocking the radiation. The study can be used for an easy evaluation of any CT room within the framework of the model of the study