The knowledge of the neutron-induced reaction cross-section is important, especially, for the fusion and fission reactor technologies. In the absence of experimental data or for cases where ...measurements are difficult, theoretical predictions of nuclear cross-sections are needed to be improved upon using refined model calculations or effective semi-empirical formulas. Accurate, physics-based modelling of neutron-induced reactions is key to all nuclear science and technology applications. In the present work, the excitation functions for (n, p), (n,
α
) and (n, 2n) reactions up to 20 MeV for stable isotopes of Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. are calculated using the EMPIRE-3.2 nuclear reaction model code using optimised values of input parameters. The experimental data available in EXFOR database for these stable isotopes are reproduced to determine the optimum parameters. The optimised parameters, so obtained, are then used to calculate the reaction cross-sections for a series of unstable nuclides for the incident neutron energy of 1–20 MeV. The calculated cross-sections are compared with the evaluated data available in literature (ENDF). We have also compared our results with the estimated cross-sections using available empirical formulas. Based on the calculations, we recommend a reliable set of parameters to estimate the (n, p), (n,
α
) and (n, 2n) cross-sections for unstable nuclides in the mass region
A
∼
40–70.
Lowest energy spectrum of the
C nucleus is analyzed in the 3
-cluster model with a deep
potential of Buck, Friedrich and Wheatley with Pauli forbidden states in the
and
waves. The direct ...orthogonalization method is applied for the elimination of the 3
Pauli forbidden states. The effects of possible first order quantum phase transition are shown in the lowest
C(
) and
C(
) states from weakly bound phase to a deep phase. The ground and lowest 2
states of the
C nucleus in the deep phase are created by the critical eigen states of the Pauli projector for the 0
and 2
three-alpha functional spaces, respectively.
Jewelry utilizes lead either directly or as a base metal. Costume jewelry requires lead before molding and plating the product with valuable metals. Therefore, such ornaments have a great potential ...to release heavy metals having health hazards. Also, jewelry makers engaged in preparing German silver, an alloy, apply lead in smelting, alloying, rolling and milling silver wires and pieces. The metal is taken up by blood, soft tissues and bone. The biological effects of lead are dependent upon the level and duration of exposure. Lead inhibits three enzymes of heme biosynthesis- δ-amino-levulinic-acid dehydratase (ALAD), coproporphyrin oxidase, and ferrochelatase, impairing heme synthesis and depressing serum level of erythropoietin resulting in decreased hemoglobin synthesis. Lead exposure also affects calcium metabolism and impair the synthesis of Calcitriol. In the present study, jewelry makers from Dhaka, Bangladesh, were shown to have significantly high levels of lead, protein, albumin, and parathormone in their blood, and significantly high amount of zinc-protoporphyrin and δ-amino-levulinic-acid in their urine. The control group, on the other hand showed significantly higher amounts of calcium (both total and ionized form) Vitamin D
3
and non-activated erythrocyte ALAD in their blood, along with hemoglobin. It might be due to inhibition of 1-α-hydroxylase enzyme in renal tubules. Lead causes nephro-toxicity and inhibits 1-α- hydroxylase enzyme leading to decreased calcitriol synthesis resulting in impaired calcium absorption across gastro-intestinal tract and renal tubules. Low Vitamin D
3
and significantly increased Parathyroid hormone (PTH) in study group has been found.
Quasi-elastic (QEL) scattering measurements have been performed using a 28Si projectile off a 90Zr target at energies around the Coulomb barrier. A Bayesian analysis within the framework of coupled ...channels (CC) calculations is performed in a large parameter space of quadrupole and hexadecapole deformations (β2 and β4) of 28Si. Our results unambiguously show that 28Si is an oblate shaped nucleus with β2=-0.38±0.01 which is in excellent agreement with results from electromagnetic probes. The sign and magnitude of quadrupole deformation along with a precise value of hexadecapole deformation (β4=+0.03±0.01) of 28Si have been determined for the first time using QEL scattering. A remarkable agreement is obtained between the experimental and calculated β4 values of 28Si based on Skyrme-Hartree-Fock method. The present results demonstrate the strong sensitivity of the quasi-elastic scattering to the sign and magnitude to the ground state deformation parameters, thus affirming its suitability to be used for rare exotic nuclei using low intensity RIBs.
The paper describes the studies on efficiency calibration and coincidence summing correction for a 3.5″×6″ cylindrical LaBr3(Ce)detector. GEANT4 simulations were made with point sources, namely, ...60Co, 94Nb, 24Na, 46Sc and 22Na. The simulated efficiencies, extracted using 60Co, 94Nb, 24Na and 46Sc that emit coincident gamma rays with same decay intensities, were corrected for coincidence summing by applying the method proposed by Vidmar et al. (2003). The method was applied, for the first time, for correcting the simulated efficiencies extracted using 22Na that emits coincident gamma rays with different decay intensities. The measured results obtained using 60Co and 22Na were found to be in good agreement with simulated results.
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•Coincidence summing correction in a large LaBr3(Ce) detector.•Estimation of corrected absolute efficiencies by employing the method suggested by Vidmar et al. (2003)•Validation of the method for a positron emitter.•The measured results obtained using 60Co and 22Na were found to be in good agreement with simulated results.
Asymmetric resonances in elastic n+19C scattering are attributed to Efimov states of such neutron-rich nuclei, that is, three-body bound states of the n+n+18C system when none of the pairs is bound ...or some of them are only weakly bound. By fitting to the general resonance shape described by Fano, we extract the resonance position, width, and the "Fano profile index." While Efimov states have been discussed extensively in many areas of physics, there is only one very recent experimental observation in trimers of cesium atoms. The conjunction that we present of the Efimov and Fano phenomena may lead to experimental realization in nuclei.
A rich set of differential cross section of the three-body
2
H(
d
,
dp
)
n
breakup reaction at 160 MeV deuteron beam energy has been measured over a large range of the available phase space. The ...experiment was performed at KVI in Groningen, the Netherlands, using the BINA detector. The cross-section data for the breakup reaction have been normalized to the simultaneously measured
2
H(
d
,
d
)
2
H elastic scattering cross section. The breakup cross sections obtained for 147 kinematically complete configurations near the quasi-free scattering kinematics are compared to the recent approximate calculations for the three-cluster breakup in deuteron–deuteron collisions. The cross sections for 294 kinematic configurations of the quasi-free scattering regime, for which no theoretical calculations exist, are also presented. Besides the three-body breakup, semi-inclusive energy distributions for the four-body
2
H(
d
,
pp
)
nn
breakup are reported.
We have carried out a systematic study of F-spin multiplets having similar product of their valence nucleons (i.e., NpNn-values) to extract the prominent features which are responsible in generating ...the identical rotational bands among them. It has been established by us from the experimental data of rare-earth region that a subsequent addition of proton pair in an isotonic set of nuclei increases their (i.e., isotones) pairing contribution whereas a reversing trend has been seen while adding a neutron pair in an isotopic set. Similar type of opposite trends have also been observed in their quadrupole deformations while adding a pair of proton and neutron, respectively, in an isotone and isotope. Thus, a simultaneous addition of both proton and a neutron pair in any one of the F-spin multiplet does not alter the pairing contribution as well as deformation structure of a newly emerging F-spin multiplet provided these multiplets belong to generalized mirror pair having same NpNn products and hence the identicity prevails between their rotational spectra. These experimentally observed opposing trends of pairing correlations and deformation parameters with the addition of a particular nucleon pair in an isotone and isotope, respectively, are also supported by our cranking model calculations. These systematic studies together with the cranking model calculations have further been extended to explore the possibilities of obtaining the identical band structures between odd-A and neighboring even-even nuclei.
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