Angular Distributions Of Proton Groups Research Articles

A study of the 30Si(d,p) 31Si reaction

The reaction 30Si(d,p) 31Si is studied at the incident deuteron energy of 12.3 MeV. Proton groups are analysed using a multi-angle magnetic spectrograph with the resolving power E/ ΔE≈1000. Angular distributions of proton groups corresponding to 14 bound states and to 8 unbound states of the 31Si nucleus are analysed using DWBA calculations. Deduced transferred orbital angular momenta and spectroscopic factors differ for some states from those obtained previously. In particular, we attribute l=1 transfer to the state at 5.281 MeV. Shell-model calculations are performed in a complete 0ℏ ω model space for positive-parity states and in a restricted 1ℏ ω model space including f7/2, p3/2 and p1/2 neutron orbits for negative-parity states. The excitation energies as well as spectroscopic strengths of most of strongly excited positive- and negative-parity states are reasonably well interpreted within the shell model.

Spectroscopic information on 36Cl from the (d,p) reaction

Abstract The reaction 35Cl(d, p)36Cl was studied at deuteron energy 12.3 MeV using a multi-angle magnetic spectrograph with resolving power E ΔE ≈2000 . Precise excitation energies of 77 states in 36Cl up to 7 MeV are presented. The level energies of some states were measured with a precision of 70–80 eV; several new states were found. Angular distributions of proton groups corresponding to 51 states in 36Cl were analysed using DWBA calculations. Transferred orbital angular momenta and absolute values of spectroscopic factors were deduced. Spectroscopic factors for 36 states are given for the first time. The substantial parts of single-particle strengths for If and 2p orbits are exhausted by the observed l = 3 and l = 1 transitions. Spectroscopic strengths for the positive-parity states show that 2s and 1d orbits in the ground state of 35Cl are much more empty than should follow from simple-shell-model or from calculations made in the full space of sd-shell-model wave functions by Wildenthal et al.

Spectroscopic information on 35S and 37S from the (d, p) reaction

The reactions 34S(d,p) 35S and 36S(d,p) 37S were studied at the incident deuteron energy of 12.3 MeV. Proton groups were analysed using a multi-angle magnetic spectrograph with the resolving power E ΔE ≈ 1400 . Precise Q-values corresponding to 13 states of 35S up to the excitation energy of 7483 keV and 22 states of 37S up to the excitation energy of 6406 keV are presented. The ground-state transition Q-value for the reaction 36S(d,p) 37S was found to be 2079.12 ± 0.13 keV. Angular distributions of proton groups corresponding to 6 states in 35S and to 11 states in 37S were analysed using DWBA calculations. Transferred orbital angular momenta and spectroscopic factors were deduced. Summed spectroscopic strengths show that substantial parts of single-particle strengths for 1 f 7 2 , 2 p 3 2 and 2 p 1 2 in both reactions are exhausted b observed transitions.

States in 97, 101Ru observed in the reactions 96,100Ru(d, p)

The neutron single-particle strength distributions for the nuclei 97Ru and 101Ru have been investigated using the (d, p) reaction at a deuteron energy of 11.5 MeV, with an overall experimental resolution of approximately 25 keV. Angular distributions of proton groups leading to sixteen final states in both nuclei were measured in the angular range 15.0 to 67.5°. The measured cross sections are analyzed in the framework of the distorted waves Born approximation to deduce l-values and spectroscopic factors of the states in the residual nuclei. The ground-state Q-value for the 96Ru(d, p) 97Ru reaction has been determined to a much improved accuracy, Q 0 = 5.886 ± 0.003 MeV.

Investigation of the 34S(d, p)35S reaction at Ed = 10 MeV

Angular distributions of proton groups, corresponding to fifteen levels observed in the reaction 34S(d, p)35S at Ed = 10 MeV have been measured with a split-pole spectrograph equipped with position-sensitive detectors. For the levels at Ex = 0, 1.58, 1.99, 2.34, 2.73, 3.68, 3.80 and 4.20 MeV, ln = 2, 0, 3, 1, (2, 3), (1), 1 and 1, respectively, has been found from a DWBA analysis. Experimental spectroscopic factors and those following from many-particle shell-model calculations for the lowest four states are in satisfactory agreement. The ground state Q-value has been measured as Q = 4757 ± 5 keV.

Nuclear-Structure Studies in Mo and Nb Isotopes via Stripping Reactions at 12 MeV

Proton energy spectra from ($d,p$) reactions induced by 12-MeV deuterons on targets of ${\mathrm{Mo}}^{92}$, ${\mathrm{Mo}}^{94}$, ${\mathrm{Mo}}^{98}$, and ${\mathrm{Nb}}^{93}$ were measured with 7-9-keV resolution. Angular distributions of proton groups in the spectra were used to determine the $l$ values of the transitions yielding the respective proton groups. In reactions on the Mo isotopes, all of the expected strength is found for transitions leading to ${s}_{\frac{1}{2}}$, ${d}_{\frac{3}{2}}$, and ${d}_{\frac{5}{2}}$ states. In contrast with the situation in the isotonic Zr isotopes, where no ${h}_{\frac{11}{2}}$ states are known, one ${h}_{\frac{11}{2}}$ state is found in each odd-$A$ Mo isotope; however, in each case the excitation strength is only a small fraction of the expected total for that level. The total excitation strength for the ${g}_{\frac{7}{2}}$ level is also far below the expected total, and there is no evidence that this level is filling in the Mo isotopes as neutrons are added. In ${\mathrm{Nb}}^{94}$, values of $I$ for several members of the ($\ensuremath{\pi}{g}_{\frac{9}{2}}$) ($\ensuremath{\nu}{d}_{\frac{5}{2}}$) and ($\ensuremath{\pi}{g}_{\frac{9}{2}}$) ($\ensuremath{\nu}{g}_{\frac{7}{2}}$) configurations are estimated from sum rules and the presence of mixing.

The reactions 27Al(n, p) 27Mg and 28Si(n, p) 28Al at neutron energies around 8 MeV

Angular distributions of proton groups from the reactions 27Al(n, p) 27Mg and 28Si(n, p) 28Al leading to well specified states in the residual nuclei have been measured at neutron energies between 7.7 and 9.1 MeV with a scintillation counter telescope. The distributions show, if any, only slight departures from symmetry to 90°.

Vibrational Spectrum ofCd112

The energies and angular distributions of proton groups produced in the ${\mathrm{Cd}}^{111}(d,p){\mathrm{Cd}}^{112}$ reaction were measured with an over-all resolution of 20 keV. A distorted-wave analysis, employing experimentally determined optical-model parameters, was used to extract values of ${l}_{n}$ and spectroscopic strengths for states up to 3.3-MeV excitation in ${\mathrm{Cd}}^{112}$. Wave functions of ${\mathrm{Cd}}^{111}$ and ${\mathrm{Cd}}^{112}$ calculated in the random-phase approximation are tested both by comparison of sum-rule predictions with the summed spectroscopic factors, and by comparison of individual spectroscopic factors with those predicted by the microscopic theory of nuclear vibrations for states in ${\mathrm{Cd}}^{111}$ and the zero-, one-, and two-phonon states in ${\mathrm{Cd}}^{112}$.

The level structure of 18O and 19O by stripping reactions

The (d, p) reactions on 16O, 18O and 18O were investigated at a deuteron energy of 5.56 MeV, with a view to studying the 18O energy levels. The reaction Q values of the ground state transitions in 17O(d, p) 18O and 18O(d, p) 19O were determined to be 5.820±0.010 and 1.734±0.010 MeV respectively. The positions of several energy levels in 18O and 19O were established. Angular distributions of proton groups leading to some levels in 17O, 18O and 19O were measured. The experimental results were analysed using the Butler-Born theory and an estimate was obtained of the amplitudes of the simple shell model configurations and deformed states in several levels of 18O. The results compare fairly well with recent theoretical estimates by Federman and Talmi.

The angular distributions of proton groups from the deuteron bombardment of neon

The angular distributions of a number of proton groups from the bombardment of neon by 2.4 MeV deuterons have been measured, and estimates of the absolute differential cross-sections are given. There is evidence that at least one group with Q value in the region of zero which shows simple stripping characteristics at 8.5 MeV, does not do so at 2.4 MeV deuteron energy.

Stripping analysis of the reaction Na 23 (d, p) Na 24

A heavy particle magnetic spectrograph has been used to study the energies and angular distributions of proton groups emitted from a sodium target bombarded with 8.60 MeV deuterons. New excited states in Na 24 have been observed at 4.74±0.04 MeV and 5.13±0.08 MeV. The angular distributions of some proton groups have been compared with curves calculated from deuteron stripping theories. While an s- or d- wave neutron capture is observed for the low lying levels, a p-wave is found to dominate the higher excited states.

Scattering of Protons by Silicon and Sulphur

The angular distributions of protons in elastic and inelastic scattering by Si and S have been studied, changing the bombarding energy from 4.95 Mev to 5.45 Mev with the interval of 100 Kev. The angular distributions of proton groups from the reaction Si 28 ( p , p ')Si 28* ( Q =-1.78 Mev) are nearly symmetric about 90° for any bombarding energy and the total cross-section changes appreciably with the incident energy. On the other hand, the results for the reaction S 32 ( p , p ')S 32 ( Q =-2.24 Mev) show large variation with the energy in both angular distribution and total cross-section. The energy dependence of the angular distribution of elastically scattered protons by silicon is found to be more remarkable than that by sulphur in the energy region studied.

Proton-Gamma Ray Angular Correlations in theSi28(d, pγ)Si29Reaction

The Si/sup 28/(d,p gamma )Si/sup 29/ reaction was studied by measuring angular distributions of the protons leaving Si/sup 29/ in its first and second excited states and by measuring the correlation between the protons of each group and the gamma rays emitted from the corresponding level. The angular distributions of proton groups p/sub 1/ and p/sub 2/ exhibit large peaks in the backward direction, indicating that heavy-particle stripping may be important. The (p/sub 1/, gamma ) correlations were found to be isotropic to plus or minus 6%. This is substantially different from the correlation which was observed at a higher deuteron energy. The (p/sub 2/, gamma ) cor relations are consistent wlth a 5/2+ level in Si/sup 29/ at 2.03 Mev. One (p, gamma ) correlation shows a 20% anisotropy in the plane perpendicular to the direction taken by the recoil nucleus, while another (p, gamma ) correlation is essentially isotropic. (auth)

N15(d, p)N16Reaction and the Low Excited States ofN16

The angular distributions of proton groups to the first three excited states of ${\mathrm{N}}^{16}$, produced in the reaction ${\mathrm{N}}^{15}(d, p){\mathrm{N}}^{16}$, have been measured at ${E}_{d}=2.75$ Mev in the laboratory system. These distributions show strong resemblance to the predictions of stripping theory and have been compared to curves calculated from the formula for the differential cross section given by Bhatia et al. The most reasonable values of ${l}_{n}$ in the reactions leading to the states at 0.113, 0.300, and 0.391 Mev are ${l}_{n}=0, 2, \mathrm{and} 0$, respectively, indicating spin and parity assignments ${0}^{\ensuremath{-}}$ or ${1}^{\ensuremath{-}}$; ${1}^{\ensuremath{-}}$, ${2}^{\ensuremath{-}}$, or ${3}^{\ensuremath{-}}$; and ${0}^{\ensuremath{-}}$ or ${1}^{\ensuremath{-}}$, respectively, for these three states.