OXBASH Code Research Articles

High-spin states of the semimagic nucleusPr141

High-spin states of the semimagic nucleus $^{141}\mathrm{Pr}$ have been investigated by in-beam $\ensuremath{\gamma}$-spectroscopic techniques using the fusion-evaporation $^{138}\mathrm{Ba}(^{7}\mathrm{Li},\phantom{\rule{0.16em}{0ex}}4n)$ reaction at a beam energy of 38 MeV. The level scheme of $^{141}\mathrm{Pr}$ has been extended up to $\ensuremath{\sim}6.2$ MeV in excitation energy and $35/2 \ensuremath{\hbar}$ in spin. A total of 14 new levels and 30 new transitions have been assigned to $^{141}\mathrm{Pr}$ on the basis of $\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$ coincidence information. The observed level structures are discussed in light of the available experimental data and shell model calculations with the oxbash code. According to the calculations, most of the observed levels of $^{141}\mathrm{Pr}$ are from the proton excitations above the $Z=50$ shell. Possible evidence for the neutron excitations across the $N=82$ gap in $^{141}\mathrm{Pr}$ is also discussed and compared with other $N=82$ isotones.

Energy Levels Calculations of 30Si and 31Si Isotopes Using OXBASH Code

In this article by using OXBASH shell model code the energy levels of Silicon isotopes 30Si and 31Si are calculated. This code which is based on one of the most applicable nuclear models, deals with evaluating energy levels. Applying the program for each isotope using the defined codes, introduces several files which each file contains a set of data. Meanwhile, the ground state and excitation energies together with number of nucleons in each energy level are calculated by OXBASH code. Programs will be reliable only when results meet experimental procedures. A compilation of SD-shell energy levels calculated with the USD Hamiltonian and has been published around 1988. A comparison had been made between our results and the available experimental data to test theoretical shell model description of nuclear structure in Silicon isotopes. The calculated energy spectrum is in good agreement with the available experimental data.

Energy Levels Calculations of 24Mg and 25Mg Isotopes using OXBASH Code

In this article by using OXBASH shell model code the energy levels of Magnesium isotopes 24Mg and 25Mg are calculated. This code which is based on one of the most applicable nuclear models, deals with evaluating energy levels. Applying the program for each isotope using the defined codes, introduces several files which each file contains a set of data. Meanwhile, the ground state of excitation energy evaluated by OXBASH code together with energy levels and also probable places for nucleons’ placements in each energy level. Programs will be reliable only when results meet experimental procedures. A compilation of SD-shell energy levels calculated with the USD Hamiltonian and has been published around 1988. A comparison had been made between our results and the available experimental data to test theoretical shell model description of nuclear structure in Magnesium isotopes. The calculated energy spectrum is in good agreement with the available experimental data.

Energy Levels Calculations of 20Ne and 21Ne Isotopes

In this article by using OXBASH shell model code the energy levels of Neon isotopes 20Ne and 21Ne are calculated. This code which is based on one of the most applicable nuclear models, deals with evaluating energy levels. Applying the program for each isotope using the defined codes, introduces several files which each file contains a set of data. Meanwhile, the ground state of excitation energy evaluated by OXBASH code together with energy levels and also probable places for nucleons’ placements in each energy level. Programs will be reliable only when results meet experimental procedures. A compilation of SD-shell energy levels calculated with the USD Hamiltonian and has been published around 1988. A comparison had been made between our results and the available experimental data to test theoretical shell model description of nuclear structure in Neon isotopes. The calculated energy spectrum is in good agreement with the available experimental data.

Calculation of the Energy Levels of Phosphorus Isotopes (A=31 to 35) by Using OXBASH Code

Phosphorus (P) has 23 isotopes from 24P to 46P, only one of these isotopes, 31Pis stable; such as this element is considered as a monoisotopic element. The longest-lived radioactive isotopes are 33P with a half-life of 25.34 days and the least stable is 25P with a half-life shorter than 30ns. Almost all of them are high energy beta-emitters which have valuable applications in medicine, industry, and tracer studies. Calculations of energy level properties of the Phosphor isotopic chain with A = 31 (N=15) to 35 (N=20) calculated through shell model calculations using the shell model code OXBASH for Windows. A compilation of sd-shell energy levels calculated with the USD Hamiltonian has been published around 1988.A comparison had been made between our results and the available experimental data and USD energies to test theoretical shell model description of nuclear structure in Phosphor nuclei. The calculated energy spectrum is in good agreement with the available experimental data.

Energy Levels Calculations of 26Al and 29Al Isotopes

In this article by using OXBASH shell model code the energy levels of Aluminum isotopes 28Al and 29Al are calculated. This code which is based on one of the most applicable nuclear models, deals with evaluating energy levels. Applying the program for each isotope using the defined codes, introduces several files which each file contains a set of data. Meanwhile, the ground state of excitation energy evaluated by OXBASH code together with energy levels and also probable places for nucleons placements in each energy level. Programs will be reliable only when results meet experimental procedures. A compilation of SD-shell energy levels calculated with the USD Hamiltonian and has been published around 1988. A comparison had been made between our results and the available experimental data to test theoretical shell model description of nuclear structure in Aluminum isotopes. The calculated energy spectrum is in good agreement with the available experimental data.

Energy Levels Calculations of 32Cl and 33Cl Isotopes

In this article by using OXBASH shell model code the energy levels of Chlorine isotopes 32Cl and 33Cl are calculated. This code which is based on one of the most applicable nuclear models, deals with evaluating energy levels. Applying the program for each isotope using the defined codes, introduces several files which each file contains a set of data. Meanwhile, the ground state of excitation energy evaluated by OXBASH code together with energy levels and also probable places for nucleons placements in each energy level. Programs will be reliable only when results meet experimental procedures. A compilation of SD-shell energy levels calculated with the USD Hamiltonian and has been published around 1988. A comparison had been made between our results and the available experimental data to test theoretical shell model description of nuclear structure in Chlorine isotopes. The calculated energy spectrum is in good agreement with the available experimental data.

Energy Levels Calculations of 29S, 30S and 31S Isotopes

In this article by using OXBASH shell model code the energy levels of Sulfur isotopes 29S – 31S are calculated. This code which is based on one of the most applicable nuclear models, deals with evaluating energy levels. Applying the program for each isotope using the defined codes, introduces several files which each file contains a set of data. Meanwhile, the ground state of excitation energy evaluated by OXBASH code together with energy levels and also probable places for nucleons placements in each energy level. Programs will be reliable only when results meet experimental procedures. A compilation of SD-shell energy levels calculated with the USD Hamiltonian and has been published around 1988. A comparison had been made between our results and the available experimental data to test theoretical shell model description of nuclear structure in Sulfur isotopes. The calculated energy spectrum is in good agreement with the available experimental data.

Spectroscopy of low-lying states in odd-odd146Eu

Electron capture (EC) decay of ${}^{146}$Gd (${t}_{\frac{1}{2}}=48$ d) to the low lying states of ${}^{146}$Eu has been studied using high-resolution $\ensuremath{\gamma}$-ray spectroscopy. The ${}^{146}$Gd activity was produced by ($\ensuremath{\alpha},2n$) reaction at ${E}_{\ensuremath{\alpha}}=32$ MeV using a 93.8$%$ enriched ${}^{144}$Sm target. The level structure has been considerably modified from the measurement of $\ensuremath{\gamma}$-ray singles, $\ensuremath{\gamma}\ensuremath{\gamma}$ coincidences and decay half lives. Lifetime measurement has been performed for the 3${}^{\ensuremath{-}}$ (114.06 keV) and 2${}^{\ensuremath{-}}$ (229.4 keV) levels of ${}^{146}$Eu using the mirror symmetric centroid difference (MSCD) method with LaBr${}_{3}$ (Ce) detectors. The lifetimes for these two states have been found to be 5.38 $\ifmmode\pm\else\textpm\fi{}$ 2.36 ps and 8.38 $\ifmmode\pm\else\textpm\fi{}$ 2.19 ps respectively. Shell model calculation has been performed using oxbash code in order to interpret the results.

Structure of the isomeric states inSb123,125

Excited states in $^{123,125}\mathrm{Sb}$ have been studied following the $^{122,124}\mathrm{Sn}$($^{7}\mathrm{Li}$,\ensuremath{\alpha}2n)$^{123,125}\mathrm{Sb}$ reactions at beam energies of 35 and 37 MeV, respectively. Conversion coefficients for transitions depopulating isomeric states in $^{125}\mathrm{Sb}$ have been measured using an electron spectrometer. This has allowed firm ${J}^{\ensuremath{\pi}}$ assignments to be made and enabled the structure of the isomeric states to be compared with those in ${}^{121,127\ensuremath{-}131}$Sb and in the neighboring even-$A$ tin isotopes. The half-lives of the ${J}^{\ensuremath{\pi}}={\frac{23}{2}}^{+}$ isomeric states in $^{123}\mathrm{Sb}$ and $^{125}\mathrm{Sb}$ have been measured to be 66(4) \ensuremath{\mu}s and 272(16) ns, respectively. The half-lives of the ${J}^{\ensuremath{\pi}}={\frac{19}{2}}^{+},{\frac{19}{2}}^{\ensuremath{-}}$, and ${\frac{15}{2}}^{\ensuremath{-}}$ states in $^{125}\mathrm{Sb}$ have been measured as 31(2) ns, 28.0(7) \ensuremath{\mu}s, and 4.1(2) \ensuremath{\mu}s, respectively. The transition probabilities for the transitions depopulating these states are compared with those in ${}^{121,127\ensuremath{-}131}$Sb and with the results of shell-model calculations using the Oxbash code and the SN100PN interaction in a restricted model space.

Hyperfine interaction of 25Al in α-Al2O3 and its quadrupole moment

The electric quadrupole (Q) moment of short-lived nucleus 25Al \((I^{\pi} = 5/2^{+}, T_{1/2} = 7.18~{\rm s})\) has been measured for the first time, by means of the β-NQR technique. The spin polarization of 25Al was produced in heavy ion collisions and was kept in a α-Al2O3 single crystal for as long as 2 s and the quadrupole coupling frequency was obtained as ∣ eqQ / h(25Al in Al2O3) ∣ = (4.05 ±0.30) MHz. From the result, the Q moment was determined as ∣ Q(25Al)∣ = (240 ±20) mb. The present Q moment is larger by 30% than the shell model value of 184 mb, calculated by OXBASH code, which may show additional deformation of the nucleus.

Structure of [formula omitted] Mo at high spins

High-spin states of 96 Mo ( Z=42 , N=54 ) nucleus have been investigated through the 82 Se( 18 O, 4n ) reaction at E b=60 MeV. The excited states have been extended upto 10 MeV and the levels with J π=20 + spins have been observed in the present experiment while the earlier information for the same was available only upto 4.8 MeV. A significant modification of the existing level scheme is also being proposed. The properties of the observed levels have been compared with shell-model calculations using OXBASH code. The analysis of the result shows that level structure exhibits mainly single particle character.

21Na(p,γ)22Mgthermonuclear rate for22Naproduction in novae

Classical novae are potential sources of $\ensuremath{\gamma}$ rays, like the 1.275 MeV gamma emission following ${}^{22}\mathrm{Na}$ beta decay, that could be detected by appropriate instruments on board of future satellites like INTEGRAL. It has been shown that the production of ${}^{22}\mathrm{Na}$ by novae is affected by the uncertainty on the ${}^{21}\mathrm{Na}(p,\ensuremath{\gamma}{)}^{22}\mathrm{Mg}$ rate and in particular by the unknown partial widths of the ${E}_{x}=5.714,$ ${J}^{\ensuremath{\pi}}{=2}^{+},$ ${}^{22}\mathrm{Mg}$ level. To reduce these uncertainties, we performed shell model calculations with the OXBASH code, compared the results with available spectroscopic data, and calculated the missing partial widths. Finally, we discuss the influence of these results on the ${}^{21}\mathrm{Na}(p,\ensuremath{\gamma}{)}^{22}\mathrm{Mg}$ reaction rate and ${}^{22}\mathrm{Na}$ synthesis.

High spin states in singly closed143Pm

The high spin states in the $N=82$ odd-A ${}^{143}\mathrm{Pm}$ have been investigated by in-beam $\ensuremath{\gamma}$-spectroscopic techniques following the reactions ${}^{135}\mathrm{Ba}{(}^{11}\mathrm{B}{,3n)}^{143}\mathrm{Pm}$ at $E=47$ MeV and ${}^{133}\mathrm{Cs}{(}^{13}\mathrm{C}{,3n)}^{143}\mathrm{Pm}$ at $E=63$ MeV, respectively, using a gamma detector array, consisting of 12 Compton-supressed high purity germanium detectors and a multiplicity ball of 14 bismuth germanate elements. 28 new $\ensuremath{\gamma}$ rays have been assigned to ${}^{143}\mathrm{Pm}$ on the basis of the $\ensuremath{\gamma}$-ray singles and $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidence data. The level scheme of ${}^{143}\mathrm{Pm}$ has been extended up to an excitation energy of 8.4 MeV and spin $47/2\ensuremath{\Elzxh}$ and 24 new levels have been proposed. Spin-parity assignments for most of the newly proposed levels have been made using the measured directional correlation orientation ratios for strong transitions. The observed level structure is discussed in the light of available experimental data and a modest shell model calculation done by us, using the OXBASH code.

Unrestricted symmetry-projected Hartree-Fock-Bogoliubov calculations for some PF-shell nuclei

Total binding energies and yrast energy spectra of three selected 1p0f–nuclei have been calculated using an unrestricted Hartree–Fock–Bogoliubov approach with symmetry–projection before the variation. The full 1p0f–shell has been used as single–particle basis and the semi–empirical FPD6 interaction as effective Hamiltonian. The results are compared to those of truncated shell–model calculations performed with the OXBASH code. In the middle of the 1p0f–shell the variational method yields energy gains up to 4.5 MeV and thus proves to be far superior than the conventional truncation methods at least if in the latter only up to about 13000 configurations for each spin–isospin combination are admitted.

Properties of N=84, even-even nuclei populated in the spontaneous fission of 248Cm

Excited states in the neutron-rich, N=84 nuclei 134Sn, 136Te and 138Xe, populated in the spontaneous fission of 248Cm, were studied to medium spins using the EUROGAM2 array. OXBASH code calculations support the experimental identification of maximum aligned configurations in these isotopes. Empirical shell model calculations agree with the proposed excitation energy of the neutron h9/2 excitation in the 132Sn region. A discrepancy between the observed and calculated excitation energy of the Iπ= 12+ level in 136Te indicates possible admixtures of collective excitations in this nucleus. Clear signs of collective excitations are observed in 138Xe.

Structure of 136Te and the problem of mass of 134Te

Neutron-rich, N=84 nuclei from the 132Sn region, populated in spontaneous fission of 248Cm, have been studied with EUROGAM 2. Excited states and their spins and parities in the 136Te nucleus were established up to 17ħ. OXBASH code calculations support the experimental identification of maximum aligned configurations in 136Te. Empirical shell model calculations for the Iπ= 14+ level in 136Te indicate that the adopted mass of the 134Te nucleus should be lowered by 200(80) keV.