Recent Articles

Decay of mass-separated ${}^{137}{Xe}$ to levels in the $N = 82$ nucleus ${}^{137}{Cs}$

W. R. Western, John C. Hill, W. L. Talbert, Jr., and W. C. Schick, Jr.

Phys. Rev. C 15, 1024 (1977) - Published 1 March, 1977

Show Abstract

The $γ$ rays following the $β$ decay of mass-separated ${}^{137}{Xe}$ to levels in ${}^{137}{Cs}$ have been studied. Of 94 $γ$ rays observed, 83 were placed in a ${}^{137}{Cs}$ level scheme consisting of 34 excited states up to 3976 keV. The results are compared with levels from single-proton transfer reactions and shell-model calculations.

RADIOACTIVITY ${}^{137}{Xe}$ [from ${}^{235}U (n, f)$ ]; measured $E_{γ}$ , $I_{γ}$ , $γ γ$ -coin. Ge(Li) detectors; ${}^{137}{Cs}$ deduced levels, $J$ , $π$ , $log ft$ . Mass-separated ${}^{137}{Xe}$ activity.

Half-lives of ${}^{238}{Pu}$ and ${}^{242}{Cm}$

H. Diamond, W. C. Bentley, A. H. Jaffey, and K. F. Flynn

Phys. Rev. C 15, 1034 (1977) - Published 1 March, 1977

Show Abstract

The ${}^{238}{Pu}$ half-life was measured at 87.71 ± 0.03 yr by observing the ${}^{238}{Pu}$ $α$ -particle activity formed from the $α$ decay of ${}^{242}{Cm}$ . Samples of ${}^{242}{Cm}$ were counted three times in a 262 day interval, leading to a ${}^{242}{Cm}$ half-life of 162.76 ± 0.04 days. Both values agree well with measurements made by other methods.

RADIOACTIVITY ${}^{238}{Pu}$ ; measured $T_{\frac{1}{2}}$ , precise gravimetric aliquots, high precision $α$ counting, ${}^{242}{Cm}$ ; measured $T_{\frac{1}{2}}$ .

Nuclear orientation of ${}^{125}{Sb}$ in ${Pd}_{2}$ MnSb observed with the Mössbauer effect of ${}^{125}{Te}$

G. Langouche, B. B. Triplett, N. S. Dixon, S. S. Hanna, and P. Boolchand

Phys. Rev. C 15, 1043 (1977) - Published 1 March, 1977

Show Abstract

Nuclear orientation of ${}^{125}{Sb}$ in ${Pd}_{2}$ MnSb at 139 mK was observed with the Mössbauer effect of ${}^{125}{Te}$ . From the Mössbauer spectrum, the signs of the magnetic moments of ${}^{125}{Sb}$ and ${}^{125}{Te}^{m}$ were found to be positive and negative, respectively. A ${}^{57}{Co}$ Mössbauer thermometer was used to determine the temperature of the sample attached to a ${}^{3}{He}$ - ${}^{4}{He}$ refrigerator.

RADIOACTIVITY oriented ${}^{125}{Sb}$ in ${Pd}_{2}$ MnSb; measured Mössbauer effect of ${}^{125}{Te}$ level, $E = 35.5$ keV with ZnTe absorber; ${}^{125}{Sb}$ , ${}^{125}{Te}^{m}$ deduced signs of magnetic moment $μ$ .

Gamma-ray decay schemes for ${}^{93}{Kr}$ , ${}^{93}{Rb}$ , and ${}^{93}{Sr}$

C. J. Bischof and W. L. Talbert, Jr.

Phys. Rev. C 15, 1047 (1977) - Published 1 March, 1977

Show Abstract

The $γ$ rays following the $β$ decays of ${}^{93}{Kr}$ , ${}^{93}{Rb}$ , and ${}^{93}{Sr}$ have been studied, using Ge(Li) detectors for singles and coincidence measurements. A level scheme for ${}^{93}Y$ is reported which contains 36 excited levels and 143 of the 162 observed $γ$ rays in the decay of ${}^{93}{Sr}$ . For the decay of ${}^{93}{Rb}$ , 243 $γ$ rays were observed, with 231 placed in a level scheme for ${}^{93}{Sr}$ consisting of 74 excited levels. The decay of ${}^{93}{Kr}$ was observed to have 217 $γ$ rays, 203 of which are placed in a level scheme for ${}^{93}{Rb}$ comprising 56 excited levels. Over 98% of the observed $γ$ -ray intensity is contained in each of the level schemes. Spin and parity assignments are proposed, whenever possible, on the basis of $γ$ -ray transition probabilities and deduced $log ft$ values. A comparison is made with available reaction data for the ${}^{93}Y$ level scheme, and some of the levels in each decay scheme are interpreted in terms of the nuclear shell model.

RADIOACTIVITY ${}^{93}{Kr}$ , ${}^{93}{Rb}$ , ${}^{93}{Sr}$ [from ${}^{235}U (n, f)$ ]; measured $E_{γ}$ , $I_{γ}$ , $γ - γ$ coin. Ge(Li) detectors. ${}^{93}{Rb}$ , ${}^{93}{Sr}$ , ${}^{93}Y$ deduced levels, $J$ , $π$ , $log ft$ . Mass-separated ${}^{93}{Kr}$ activity.

Double $K$ -shell vacancy creation in the decay of ${}^{109}{Cd}$

C. W. E. van Eijk and J. Wijnhorst

Phys. Rev. C 15, 1068 (1977) - Published 1 March, 1977

Show Abstract

The probability $P_{KK} (IC)$ of double $K$ -shell vacancy creation per $K$ internal conversion of the 88 keV $E 3$ transition in the decay of ${}^{109}{Cd}$ has been determined by means of a $K α$ -x-ray- $K$ -x-ray coincidence experiment: $P_{KK} (IC) = (2.8 \pm 0.7) \times 10^{- 5}$ . The energy shift of the $K α_{1}$ hypersatellite x-ray line was found to be (532 ± 12) eV.

RADIOACTIVITY ${}^{109}{Cd}$ ; measured $K α$ -x-ray- $K$ -x-ray coincidences, deduced double $K$ -shell vacancy probability of 88 keV $E 3$ transition and $K α_{1}$ hypersatellite x-ray shift.

Measurement of the internal pair emission branch of the 7.654-MeV state of ${}^{12}C$ , and the rate of the stellar triple- $α$ reaction

R. G. H. Robertson, R. A. Warner, and Sam M. Austin

Phys. Rev. C 15, 1072 (1977) - Published 1 March, 1977

Show Abstract

The internal pair decay of the $O^{+}$ 7.65-MeV state of ${}^{12}C$ has been observed in coincidence with inelastic protons from ${}^{12}C (p, p^{'}) {}^{12}C (7.65)$ , using a plastic scintillator of essentially $4 π$ sr solid angle. The branching ratio measured, $\frac{Γ_{π}}{Γ} = (6.0 \pm 1.1) \times 10^{- 6}$ , is in excellent agreement with the previous measurement by Alburger, and reduces the uncertainty in the stellar triple- $α$ reaction rate by almost a factor of 2. Implications for the astrophysical production of ${}^{12}C$ and ${}^{16}O$ are discussed.

NUCLEAR STRUCTURE ${}^{12}C$ , 7.654-MeV state; measured $\frac{Γ_{π}}{Γ}$ . Stellar helium burning.

Family of nuclear mass relations

J. E. Monahan and F. J. D. Serduke

Phys. Rev. C 15, 1080 (1977) - Published 1 March, 1977

Show Abstract

A family of simple nuclear mass relations, which includes as members the Garvey-Kelson transverse and longitudinal relations, is presented. Each member of this family gives a prediction of roughly equal statistical accuracy for the unknown mass of a given nuclide. The average of this family is statistically more reliable than is any single prediction. The essential physical observation that leads to these relations is that the empirical neutron-proton effective interaction is generally weak and that the strength of this interaction is strongly correlated separately for neighboring even- $A$ and for neighboring odd- $A$ nuclei.

NUCLEAR STRUCTURE Relations among ground-state energies of neighboring nuclei.

Self-consistent quasiparticle-phonon coupling for superfluid nuclei

J. D. Immele and G. L. Struble

Phys. Rev. C 15, 1085 (1977) - Published 1 March, 1977

Show Abstract

The utility of the anomalous Green's function formalism is physically motivated as a description of superfluid finite Fermi systems. The quasiparticle self-energy is then derived from a generalized six-point response function with the assumption that three-body correlations are negligible. An approximate calculation of the self-energy includes the usual core-polarization diagram, a backward-exchange diagram with ground state correlations, and higher-order diagrams that correct for exclusion-principle violations in the propagation of the quasiparticle and the microscopic phonon. Intermediate lines in the self-energy are described self-consistently, thereby including multiple-phonon core excitations. It is shown that the equation for the self-energy may be solved by matrix diagonalization with coupling of the even- and odd-nuclear eigenmodes. Renormalized phonons are calculated by taking into account the distribution of quasiparticle strength in the solution of the Bethe-Salpeter equation. The self-energy and phonon are calculated self-consistently.

NUCLEAR STRUCTURE Green's function method with pairing. Self-consistent RPA, collective effects in odd- $A$ nuclei.

Self-consistent quasiparticle-phonon coupling calculations for deformed superfluid nuclei in the rare earth region

J. D. Immele and G. L. Struble

Phys. Rev. C 15, 1103 (1977) - Published 1 March, 1977

Show Abstract

The self-consistent quasiparticle-phonon coupling equations are solved for deformed superfluid nuclei in the rare earth region. Parameters are chosen to agree with previous calculations, and the solutions for $γ$ -, $β$ -, and octupole-vibrational states are compared to experiments and to previous descriptions of both even- and oddmass nuclei. The importance of exclusion principle violations in the rare earth region is noted as well as the interference of pairing and quadrupole correlations in the even nuclei with $A \sim 164$ . An "intruder" state is predicted in the Eu and Tb isotopes. The splitting of the $K \pm 2$ states in ${}^{165}{Ho}$ and ${}^{167}{Er}$ is derived from higher-order contributions to the self-energy.

NUCLEAR THEORY Green's function method with pairing. Self-consistent RPA, collective effects in odd- $H$ rare earth nuclei.

Single-particle Schrödinger fluid. I. Formulation

Kit-Keung Kan and James J. Griffin

Phys. Rev. C 15, 1126 (1977) - Published 1 March, 1977

Show Abstract

The problem of a single quantal particle moving in a time-dependent external potential well is formulated specifically to emphasize and develop the fluid dynamical aspects of the matter flow. This idealized problem, the single-particle Schrödinger fluid, is shown to exhibit already a remarkably rich variety of fluid dynamical features, including compressible flow and line vortices. It provides also a sufficient framework to encompass simultaneously various simplified fluidic models for nuclei which have earlier been postulated on an ad hoc basis, and to illuminate their underlying restrictions. Explicit solutions of the single-particle Schrödinger fluid problem are studied in the adiabatic limit for their mathematical and physical implications (especially regarding the collective kinetic energy). The basic generalizations for extension of the treatment to the many-body Schrödinger fluid are set forth.

NUCLEAR STRUCTURE Fluid dynamical formulation of quantum mechanics, single-particle behavior in nuclear collective motion, fission and heavy-ion collision, inertial parameter, adiabatic approximation.

RAPID COMMUNICATION

$J^{π}$ of the $E_{x} = 4.52$ MeV state in ${}^{22}{Na}$ via the ${}^{12}C ({}^{12}C, d γ) {}^{22}{Na}$ reaction

A. H. Lumpkin, G. J. KeKelis, K. W. Kemper, and J. D. Fox

Phys. Rev. C 15, 1152(R) (1977) - Published 1 March, 1977

Show Abstract

The enhanced population of the 4.522 MeV state in ${}^{22}{Na}$ at $E_{c . m .} = 19.4$ MeV in the ${}^{12}C ({}^{12}C, d) {}^{22}{Na}$ reaction is confirmed with the particle- $γ$ coincidence technique. Deuteron- $γ$ angular correlation results, lifetime measurements, and transmission coefficient calculations combine to allow only a $J^{π} (4.522) = 7^{+}$ assignment.

NUCLEAR REACTIONS ${}^{12}C ({}^{12}C, d γ)$ , $E_{c . m .} = 19.41$ MeV; measured $E_{d}$ , $E_{γ}$ , $d - γ$ coincidence; ${}^{22}{Na}$ , $J^{π}$ for state at 4.522 MeV.

RAPID COMMUNICATION

Assignments of $J^{π}$ in ${}^{58}{Ni}$ via ( $α, α^{'}$ ) and ( ${}^{6}{Li}$ , $d$ ) reactions

G. Guillaume, F. C. Jundt, H. W. Fulbright, J. C. D. Milton, and C. L. Bennett

Phys. Rev. C 15, 1156(R) (1977) - Published 1 March, 1977

Show Abstract

Measurements of ${}^{58}{Ni} (α, α^{'}) {}^{58}{Ni}$ angular distributions have been extended to small angles and disagreements between $J^{π}$ assignments based on earlier ( $α, α^{'}$ ), and ( ${}^{6}{Li}$ , $d$ ) measurements have been explained and resolved.

NUCLEAR REACTIONS ${}^{58}{Ni} (α, α^{'})$ , $E_{α} = 30$ MeV; measured $\frac{d σ}{d Ω}$ , deduced $J^{π}$ for 5.59 and 6.02 MeV levels.

RAPID COMMUNICATION

Neutron removal from ${}^{7}{Li}$ by $π^{\pm}$

Richard R. Silbar

Phys. Rev. C 15, 1158(R) (1977) - Published 1 March, 1977

Show Abstract

The deviations of the $π^{\pm}$ -induced neutron knockout cross section ratios from the impulse approximation, as measured in a recent deexcitation $γ$ ray experiment on ${}^{7}{Li}$ , are shown to be in good agreement with the modified nucleon charge exchange model with reasonable charge exchange probabilities.

NUCLEAR REACTIONS Ratios of $σ [{}^{7}{Li} (π^{\pm}, π N) {}^{6}{Li}^{*} (3.56 MeV]$ , detect deexcitation $γ$ , $T_{π} = 50 to 290$ MeV, probability of recoil nucleon charge exchange.

RAPID COMMUNICATION

( $\vec{t}, p$ ) reaction to unnatural parity levels in ${}^{58}{Fe}$ and ${}^{60}{Ni}$

R. N. Boyd, W. P. Alford, E. R. Flynn, and R. A. Hardekopf

Phys. Rev. C 15, 1160(R) (1977) - Published 1 March, 1977

Show Abstract

The ${}^{56}{Fe} (\vec{t}, p)$ and ${}^{58}{Ni} (\vec{t}, p)$ reactions to unnatural partity levels have been studied at $E_{t} = 17$ MeV. Two-step reaction calculations are reasonably successful in reproducing the principal features of the data. The predicted cross sections and analyzing powers exhibit a large sensitivity to the nuclear structure.

NUCLEAR REACTIONS ${}^{56}{Fe}$ , ${}^{58}{Ni} (t, p)$ , $E = 17$ MeV; measured $σ (θ)$ , $A (θ)$ for reaction to unnatural parity levels in ${}^{58}{Fe}$ and ${}^{60}{Ni}$ . Enriched targets. Sequential transfer reaction calculations.

RAPID COMMUNICATION

Determination of nuclear amplitudes from the study of Coulomb-nuclear interference

L. C. Liu and C. M. Shakin

Phys. Rev. C 15, 1164(R) (1977) - Published 1 March, 1977

Show Abstract

We compare the West-Yennie method for the study of Coulomb-nuclear interference with a more accurate method based upon an exact solution for the phase shifts in the presence of nuclear and Coulomb interactions. Making use of nuclear amplitudes obtained in a previous study of pion- ${}^{4}{He}$ elastic scattering, we show that the West-Yennie method, originally proposed for the analysis of high-energy scattering, is of limited application at low and intermediate energies. In particular, the use of that method to determine the real part of the forward (nuclear) amplitude will lead to significant errors at low energies.

NUCLEAR REACTIONS Coulomb-nuclear interference. Accuracy of the West-Yennie method at low energies.

RAPID COMMUNICATION

Angular momentum determination of resonances in ${}^{24}{Mg}$ + $n$ by elastic neutron scattering

D. J. Horen, J. A. Harvey, and N. W. Hill

Phys. Rev. C 15, 1168(R) (1977) - Published 1 March, 1977

Show Abstract

The angular momentum values of 15 resonances in ${}^{24}{Mg}$ + $n$ have been determined by elastic neutron scattering. The change in shape of the differential cross section [i.e., $σ_{lJ} (E, θ)$ ] versus angle has been observed for most of these resonances. Assignments of $l = 2$ for five resonances could be made on the basis of their distinct interference pattern in the 90° cross section data.

NUCLEAR REACTIONS ${}^{24}{Mg} (n, n)$ , $E = 0.4 - 1.8$ MeV; measured $σ_{lJ} (E_{n}, θ)$ ; resonance levels in ${}^{25}{Mg}$ compound system; determined $l$ values.

RAPID COMMUNICATION

Fission-fragment anisotropy at the ${}^{238}U (n, 2 n f)$ threshold

R. Abegg and R. Wagner

Phys. Rev. C 15, 1171(R) (1977) - Published 1 March, 1977

Show Abstract

The angular distributions of fragments from neutron-induced fission of ${}^{238}U$ are measured by means of glass plates in the energy range $13.5 \leq E_{n} (MeV) \leq 17.5$ . The behavior of the angular anisotropy in this energy region, where ( $n, f$ ), ( $n, nf$ ), and ( $n, 2 n f$ ) reactions are possible, shows a clear increase at the ${}^{238}U (n, 2 n f)$ threshold.

NUCLEAR REACTIONS, FISSION ${}^{238}U (n, f)$ $E_{n} = 13.5 to 17.5$ MeV; measured fission-fragment anisotropy $A (E_{n}, θ_{fragment})$ .

RAPID COMMUNICATION

Mean lifetimes of levels in ${}^{19}{Ne}$

C. Lebrun, F. Guilbault, P. Avignon, and Y. Deschamps

Phys. Rev. C 15, 1174(R) (1977) - Published 1 March, 1977

Show Abstract

The Doppler-shift attenuation method has been applied in conjunction with the ${}^{19}F (p, n γ) {}^{19}{Ne}$ reaction to measure the mean lifetimes of four levels in ${}^{19}{Ne}$ . The present result (140 ± 35 fs) for the mean lifetime of the level at 2794 keV is not in agreement with the only previous measurement. The $\frac{9}{2^{+}} \to \frac{5}{2^{+}}$ $E 2$ transition strength deduced from our result is consistent with shell-model calculations.

NUCLEAR REACTIONS ${}^{19}F (p, n γ)$ , $E = 12$ MeV; measured $E_{γ}$ , Doppler shifts; ${}^{19}{Ne}$ deduced energy levels, lifetimes, $B (Λ)$ .

RAPID COMMUNICATION

Destructive interference between direct and indirect processes in ( $p, t$ ) reactions on spherical vibrational nuclei and strong resemblance to that in ( $p, t$ ) reactions on well-deformed nuclei

K. Yagi, Y. Aoki, M. Matoba, and M. Hyakutake

Phys. Rev. C 15, 1178(R) (1977) - Published 1 March, 1977

Show Abstract

As evidence of a phase transition of the interference between direct and inelastic multistep processes in two-neutron pickup reactions exciting the first $2^{+}$ state of spherical vibrational nuclei, a destructive interference has been observed in ${}^{A + 2}{Pd} (p, t) {}^{A}{Pd} (2_{1}^{+})$ reactions. A strong similarity between the ${}^{104, 108, 110}{Pd} (p, t) {}^{102, 106, 108}{Pd} (2_{1}^{+})$ cross sections and the ${}^{158}{Gd} (p, t) {}^{156}{Gd} (2_{1}^{+})$ cross section is discussed.

NUCLEAR REACTIONS ${}^{104, 108, 110}{Pd} (p, t)$ , $E = 52$ MeV; measured $σ (θ)$ , coupled channel analysis.

RAPID COMMUNICATION

Form factor for the electroexcitation of the 5.36 MeV transition in ${}^{6}{Li}$

L. W. Fagg, R. A. Lindgren, W. L. Bendel, and E. C. Jones, Jr.

Phys. Rev. C 15, 1181(R) (1977) - Published 1 March, 1977

Show Abstract

Using 180° electron scattering, two experimental points are determined for the form factor curve for the excitation of the 5.36 MeV transition in ${}^{6}{Li}$ at low momentum transfer. These results confirm earlier work at other laboratories.

NUCLEAR REACTIONS ${}^{6}{Li} (e, e^{'})$ , $θ = 180 °$ , $E = 40.5, 50.5$ ; measured $σ (E)$ for excitation of 5.36 MeV state, deduced form factor values.

Select page:

Physical Review C

Recent Articles

Filter

Recent Issues

Decay of mass-separated ${}^{137}{Xe}$ to levels in the $N = 82$ nucleus ${}^{137}{Cs}$

Half-lives of ${}^{238}{Pu}$ and ${}^{242}{Cm}$

Nuclear orientation of ${}^{125}{Sb}$ in ${Pd}_{2}$ MnSb observed with the Mössbauer effect of ${}^{125}{Te}$

Gamma-ray decay schemes for ${}^{93}{Kr}$ , ${}^{93}{Rb}$ , and ${}^{93}{Sr}$

Double $K$ -shell vacancy creation in the decay of ${}^{109}{Cd}$

Measurement of the internal pair emission branch of the 7.654-MeV state of ${}^{12}C$ , and the rate of the stellar triple- $α$ reaction

Family of nuclear mass relations

Self-consistent quasiparticle-phonon coupling for superfluid nuclei

Self-consistent quasiparticle-phonon coupling calculations for deformed superfluid nuclei in the rare earth region

Single-particle Schrödinger fluid. I. Formulation

$J^{π}$ of the $E_{x} = 4.52$ MeV state in ${}^{22}{Na}$ via the ${}^{12}C ({}^{12}C, d γ) {}^{22}{Na}$ reaction

Assignments of $J^{π}$ in ${}^{58}{Ni}$ via ( $α, α^{'}$ ) and ( ${}^{6}{Li}$ , $d$ ) reactions

Neutron removal from ${}^{7}{Li}$ by $π^{\pm}$

( $\vec{t}, p$ ) reaction to unnatural parity levels in ${}^{58}{Fe}$ and ${}^{60}{Ni}$

Determination of nuclear amplitudes from the study of Coulomb-nuclear interference

Angular momentum determination of resonances in ${}^{24}{Mg}$ + $n$ by elastic neutron scattering

Fission-fragment anisotropy at the ${}^{238}U (n, 2 n f)$ threshold

Mean lifetimes of levels in ${}^{19}{Ne}$

Destructive interference between direct and indirect processes in ( $p, t$ ) reactions on spherical vibrational nuclei and strong resemblance to that in ( $p, t$ ) reactions on well-deformed nuclei

Form factor for the electroexcitation of the 5.36 MeV transition in ${}^{6}{Li}$

Filter

Recent Issues

Filter

Article Lookup

Enter a citation