Recent Articles

Lifetime limits for the ${}^{46}{Ca}$ $2_{1}^{+}$ (1.35-MeV) and $0_{2}^{+}$ (2.42-MeV) states

J. A. Becker, T. T. Bardin, T. R. Fisher, B. A. Watson, and E. K. Warburton

Phys. Rev. C 10, 99 (1974) - Published 1 July, 1974

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Nuclear lifetime limits $τ_{m} > 8 psec and > 6.5 psec$ , were deduced for the ${}^{46}{Ca}$ excited states at $E_{x} = 1.347 and 2.423$ MeV, respectively. These values are compared with similar measurements in ${}^{42, 44}{Ca}$ .

NUCLEAR REACTIONS ${}^{44}{Ca} (t, p)$ , $E_{t} = 2.78$ MeV; measured $σ (E_{p}, E_{γ}, θ_{σ})$ . ${}^{46}{Ca}$ deduced $τ_{m}$ . Doppler shift attenuation method.

Triton binding energies with two-body radial-distortion unitary transforms

J. P. Lavine and G. J. Stephenson, Jr.

Phys. Rev. C 9, 2095 (1974) - Published 1 June, 1974

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We determine the triton binding energies for a class of potentials that arise from radial-distortion unitary transformations. These potentials are phase-shift equivalent to a two-term Yukawa potential, which represents an average of the ${}^{3}S_{1}$ and ${}^{1}S_{0}$ nucleon-nucleon potentials. We solve an angular-momentum-decomposed version of the Faddeev-Lovelace equations that we have developed, in order to obtain the three-body binding energy $E_{T}$ . We observe that $E_{T}$ varies slightly with these potentials and we find that they yield similar deuteron wave functions in accord with the results reported by Haftel. We discuss some evidence on the sensitivity of nuclear matter and three-body calculations to off-shell variations of the two-body $t$ matrices.

[NUCLEAR STRUCTURE ${}^{3}H$ ; calculated binding energy. Solved Faddeev-Love-lace equations, angular-momentum decomposed. Deduced deuteron form factors.]

$A = 9$ isospin quartet

E. Kashy, W. Benenson, and J. A. Nolen, Jr.

Phys. Rev. C 9, 2102 (1974) - Published 1 June, 1974

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New measurements of the mass excess of the lowest $T = \frac{3}{2}$ levels in ${}^{9}{Be}$ and ${}^{9}B$ give values of 25.7406±0.0017 and 27.0711±0.0023 MeV, respectively, and indicate a definite cubic dependence for the masses of the $A = 9$ quartet which includes ${}^{9}{Li}$ and ${}^{9}C$ in their ground states. A value of 7.6±1.7 keV is obtained for the coefficient of the $T_{z}^{3}$ term which now clearly exceeds the current theoretical estimates. Precise values of excitation energy of levels in ${}^{10}B$ and ${}^{11}B$ have been obtained as part of these measurements.

[NUCLEAR REACTIONS ${}^{11}B (p, t)$ , ( $p, {}^{3}{He}$ ), $E = 42$ MeV; measured $E_{x}$ of $T = \frac{3}{2}$ levels of ${}^{9}{Be}$ and ${}^{9}B$ . ${}^{10, 11}B (p, p^{'})$ $E = 35$ MeV; measured $E_{x}$ of ${}^{10, 11}B$ levels; deduced coefficient of multiplet mass equation for $A = 9$ .]

Unitary pole expansion applied to the trinucleon problem

E. P. Harper

Phys. Rev. C 9, 2106 (1974) - Published 1 June, 1974

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The unitary pole expansion of a central local potential effective in ${}^{1}S_{0}$ and ${}^{3}S_{1}$ two-nucleon states is applied to the calculation of the trinucleon bound state and the nucleon-deuteron doublet and quartet scattering lengths. An iteration method is used to solve the Faddeev equations in both cases and Padé techniques used to find the scattering lengths. The convergence rate of the Padé approximants is found to be good in both the doublet and quartet channels and a three-term unitary pole expansion is found to give fair agreement with the exact results for the trinucleon binding energy and the scattering lengths.

[NUCLEAR REACTIONS ( $d, n$ ), $E = 0$ ; Calculated scattering lengths, binding energy ${}^{3}{He}$ . Solved Faddeev equations, Padé approximants. Unitary pole expansion local two-body potential.]

Survey of the nuclear-matter properties of the Graz potential

J. -P. Meunier, W. Plessas, J. Pigeon, and R. Nahabetian

Phys. Rev. C 9, 2114 (1974) - Published 1 June, 1974

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In this paper, we intend to deal with the nuclear-matter properties exhibited by the separable nucleon-nucleon potential recently proposed by the Graz group. This model was the basis of the first-order perturbation theory as well as of the Brückner theory $G$ -matrix calculations. We shall discuss the results and compare them with those obtained by other nonlocal potentials (Tabakin, Mongan, Hammann) and by the local Reid soft-core potential.

[NUCLEAR STRUCTURE Nonlocal separable potentials rank 3; nuclear-matter properties. Brückner theory, first order.]

Proton form factor from 0.15 to 0.79 ${fm}^{- 2}$

J. J. Murphy, II, Y. M. Shin, and D. M. Skopik

Phys. Rev. C 9, 2125 (1974) - Published 1 June, 1974

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The absolute electron-proton elastic scattering cross section has been measured by detecting the recoil protons. The proton charge form factor has been extracted for values of the square of the momentum transfer between 0.15 and 0.79 ${fm}^{- 2}$ . The rms charge radius determined from these measurements is 0.81±0.04 fm.

[NUCLEAR REACTIONS ${}^{1}H (e, p)$ , $E = 55 - 130$ MeV, measured $σ (E; E_{p}, θ)$ ; deduced charge form factor, rms charge radius.]

$T = \frac{3}{2}$ states in mass-11 nuclei

W. Benenson, E. Kashy, D. H. Kong-A-Siou, A. Moalem, and H. Nann

Phys. Rev. C 9, 2130 (1974) - Published 1 June, 1974

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A 740-keV-wide peak in the ${}^{6}{He}$ spectrum from the bombardment of ${}^{14}N$ by 70-MeV ${}^{3}{He}$ particles is identified as the mirror of the $½^{-}$ first excited state of ${}^{11}{Be}$ . The $Q$ value for the ${}^{14}N$ ( ${}^{3}{He}$ , ${}^{6}{He}$ ) ${}^{11}N$ reaction to this state is -25.03±0.10 MeV, which corresponds to a mass excess of 25.23±0.10 MeV. The analogs of this state in ${}^{11}C$ and ${}^{11}B$ were observed with the ${}^{13}C (p, t)$ and ${}^{13}C (p, {}^{3}{He})$ reactions, and the excitation energies and widths found to agree well with the previous measurements.

[NUCLEAR REACTION ${}^{14}N ({}^{3}{He}, {}^{6}{He})$ , $E = 70$ MeV measured $Q$ , deduced mass excess of ${}^{11}N$ .]

Production of Li and B in proton and alpha-particle reactions on ${}^{14}N$ at low energies

W. W. Jacobs, D. Bodansky, D. Chamberlin, and D. L. Oberg

Phys. Rev. C 9, 2134 (1974) - Published 1 June, 1974

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Cross sections have been measured for the production of ${}^{7}{Li}$ and ${}^{11}B$ from the reactions ${}^{14}N (p, 2 α) {}^{7}{Be}$ and ${}^{14}N (p, α) {}^{11}C$ from near threshold to 24 and 22 MeV, respectively, and for the production of ${}^{6}{Li}$ and ${}^{10}B$ in $α$ -particle bombardment of ${}^{14}N$ up to 42 MeV. The proton reactions were studied with activation techniques and the $α$ -particle reactions investigated using time-of-flight particle identification. These cross sections are of interest because of their relevance to the production of the light elements in nature by relatively low-energy particles. Analyses of comparative production cross sections from CNO targets indicate that it is possible to match the solar system abundances of LiBeB with reactions dominated by protons of energies below about 25 MeV, provided one accepts the higher of recent estimates of the B abundance.

[NUCLEAR REACTIONS ${}^{14}N (p, 2 α)$ , $E = 14 - 24$ MeV; ${}^{14}N (p, α)$ , $E = 5 - 22$ MeV; ${}^{14}N (α, {}^{10}B)$ , ${}^{14}N (α, {}^{6}{Li})$ , $E = 21 - 42$ MeV; measured $σ (E)$ . Astrophysical production of Li and B.]

Angular distribution and polarization of ${}^{16}O (γ, n_{0}) {}^{15}O$

W. L. Wang and C. M. Shakin

Phys. Rev. C 9, 2144 (1974) - Published 1 June, 1974

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We report a detailed calculation of the angular distribution and polarization of the photoneutrons from ${}^{16}O$ in the giant dipole region. The electric dipole ( $E 1$ ) amplitudes are obtained from a continuum shell-model calculation which reproduces the intermediate structure in the total cross section. A consistent interpretation of the angular distribution and polarization may be obtained either by (i) assuming a phenomenological giant quadrupole ( $E 2$ ) resonance, or (ii) by modifying the phase difference between the $E 1$ amplitudes. In case (ii), we do not require any $E 2$ resonance to fit the data, or, alternatively, the magnitudes of the $E 2$ amplitudes used can be taken to be in reasonable agreement with those extracted from the polarized-proton capture experiment. As we show in case (i), there is a theoretical possibility for an $E 2$ resonance. On the other hand, the present experimental results indicate the absence of such a resonance in the dipole region; this possibility is studied in case (ii).

[NUCLEAR REACTIONS ${}^{16}O (γ, n_{0})$ ; giant dipole resonance; angular distribution and polarization of photoneutrons. Giant $E 2$ resonance in ${}^{16}O$ .]

Elastic and inelastic scattering of ${}^{6}{Li}$ on ${}^{12}C$

P. K. Bindal, K. Nagatani, M. J. Schneider, and P. D. Bond

Phys. Rev. C 9, 2154 (1974) - Published 1 June, 1974

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Elastic and inelastic scattering of ${}^{6}{Li}$ on ${}^{12}C$ were studied at 36.4 MeV and 40.0 MeV incident energies. Previously published elastic scattering data for 20, 24.5, 28, 30.6, and 63 MeV incident energies as well as the present data were analyzed to obtain an energy dependent optical potential. Inelastic scattering was measured for the transitions to the states at 4.44 MeV ( $2^{+}$ ), 7.65 MeV ( $0^{+}$ ), 9.63 MeV ( $3^{-}$ ), 10.84 MeV ( $1^{-}$ ), 11.83 MeV ( $2^{-}$ ), 12.71 MeV ( $1^{+}$ ), 13.35 MeV ( $2^{-}$ ), and 14.05 MeV ( $4^{+}$ ) in ${}^{12}C$ . The angular distributions were analyzed using the distorted wave Born approximation with the usual collective form factor. Various options for the form factors and the optical potentials were investigated. It is found that the use of complex form factors generally fits the data. Results of these calculations are presented for all transitions and the values of $β$ are deduced. For the transition to the 4.44 MeV ( $2^{+}$ ) state, both the shape and magnitude of the angular distribution (and hence the state's deformation parameter $β_{2}$ ) were well reproduced.

[NUCLEAR REACTIONS ${}^{12}C$ ( ${}^{6}{Li}$ , ${}^{6}{Li}$ ), ( ${}^{6}{Li}$ , ${}^{6}{Li}$ ′), $E = 36.4 and 40.0$ MeV; measured $σ (θ)$ , deduced energy-dependent optical-model parameters for $E = 20 - 63$ MeV; DWBA analysis, deduced deformation parameters $β_{L}$ .]

Excitation functions for ( $p, n$ ) reactions on ${}^{79}{Br}$ and ${}^{127}I$

R. Collé and R. Kishore

Phys. Rev. C 9, 2166 (1974) - Published 1 June, 1974

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Excitation functions for the ${}^{79}{Br} (p, n) {}^{79}{Kr}$ and ${}^{127}I (p, n) {}^{127}{Xe}$ reactions have been determined from 3 to 25 MeV by the activation method. KBr and KI targets of natural isotopic abundances were encapsulated in Mylar to prevent escape of the gaseous ${}^{79}{Kr}$ and ${}^{127}{Xe}$ . Disintegration rates were obtained by assaying selected $γ$ rays with calibrated Ge (Li) detectors; beam intensities were determined with a Faraday cup. The measured absolute cross sections have uncertainties of less than 10% with energy uncertainties of ≲ 100 keV. The excitation functions are compared to Monte Carlo calculations based on an intranuclear-cascade statistical-evaporation model.

[NUCLEAR REACTIONS ${}^{79}{Br} (p, n) {}^{79}{Kr}$ and ${}^{127}I (p, n) {}^{127}{Xe}$ , $E = 3 - 25$ MeV; measured $σ (E)$ . Natural targets, Ge(Li) detector.]

Energy dependence of isospin mixing in compound-statistical reactions

N. T. Porile, J. C. Pacer, J. Wiley, and C. R. Lux

Phys. Rev. C 9, 2171 (1974) - Published 1 June, 1974

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The ${}^{69}{Ga}$ compound nucleus was formed at excitation energies ranging from 17 to 22 MeV in the reactions ${}^{65}{Cu} + α$ and ${}^{68}{Zn} + p$ and energy spectra of the emitted protons and $α$ particles were measured between 30 and 150°. The extent of isospin mixing between the $T_{>}$ and $T_{<}$ states of the compound nucleus was determined by comparison of the quantity $\frac{σ (p, p^{'}) σ (α, α^{'})}{σ (p, α) σ (α, p)}$ with theory and the fractional mixing was found to increase from 0 to 0.3 over the above energy range. The mixing width shows a corresponding increase from 0.2 to 16 keV. The independence hypothesis was verified at all energies by measurements of the $α$ and $np$ exit channels. The various spectra were compared with the spin-dependent statistical theory. It was not possible to fit the data for various energies with energy-independent parameters in the Fermi gas model level density expression suggesting that this expression is inadequate.

[NUCLEAR REACTIONS ${}^{68}{Zn} (p, α)$ , ( $p, p^{'}$ ), ( $p, n p$ ), $E = 11 - 16$ MeV and ${}^{65}{Cu} (α, α^{'})$ , ( $α, p$ ), ( $α, n p$ ), $E = 13.89 - 19.10$ MeV differential cross sections measured for targets forming ${}^{69}{Ga}$ compound nucleus at excitation energies of 17-22 MeV. Deduced energy dependence of isospin mixing; tested independence hypothesis and spin-dependent statistical theory.]

Scattering of 9.0-MeV neutrons by Al, Si, Fe, Ni, and Co

D. E. Velkley, D. W. Glasgow, J. D. Brandenberger, M. T. McEllistrem, J. C. Manthuruthil, and C. P. Poirier

Phys. Rev. C 9, 2181 (1974) - Published 1 June, 1974

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Measurements have been made of the differential elastic and inelastic scattering cross sections for 9.0-MeV neutrons scattered by Al, Si, Fe, Ni, and Co. These measurements were made on natural samples using a time-of-flight spectrometer with a shielded and biased liquid organic scintillator and pulse-shape discrimination. Corrections for finite geometry were made to all data using both analytical and Monte Carlo methods. Relative uncertainties in the measured cross sections are typically 2-3% and normalization uncertainties are 3-4%. Optical-model parameters were determined by fitting the elastic data. These parameters were used to determine the $\frac{(N - Z)}{A}$ dependence of the real potential strength near $A = 60$ and to compare elastic cross sections calculated using an incoherent sum of statistical-model and direct interaction contributions to the measured inelastic cross sections.

[NUCLEAR REACTIONS Al, Si, Fe, Ni, Co ( $n, n$ ), and ( $n, n^{'}$ ), $E = 9$ MeV; measured $σ (E_{n}, θ)$ .]

Mean lifetimes of levels in ${}^{59}{Cu}$

R. O. Nelson, C. R. Gould, D. R. Tilley, and N. R. Roberson

Phys. Rev. C 9, 2193 (1974) - Published 1 June, 1974

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The mean lifetimes of levels in ${}^{59}{Cu}$ below 3.6 MeV have been investigated with the Doppler-shift attenuation method and the ${}^{58}{Ni} ({}^{3}{He}, d) {}^{59}{Cu}$ reaction at 11.6 MeV. Scattered particles were detected in two $E - Δ E$ telescopes at ± 55° with respect to the beam axis, in coincidence with $γ$ rays observed at 90° in a 50- ${cm}^{3}$ Ge(Li) detector. New levels were observed at 3114 and 3615 keV. Mean lifetimes are reported for the following levels (energy in keV, lifetime in fs): 491 (830 ± 300), 914 (> 1600), 1399 (570 ±240), 2266 (310 ± 140), 2324 (36 ±5), 3043 (1150 ± 500), 3114 (20 ± 11), 3130 (10 ± 4), 3551 (< 15), 3580 (2400 ± 1400), and 3615 (< 35). The experimental results are compared with the predictions of a core-particle coupling calculation.

[NUCLEAR REACTIONS ${}^{58}{Ni} ({}^{3}{He}, d γ)$ , $E_{{}^{3}{He}} = 11.6$ MeV; measured $E_{γ} (θ)$ , Doppler-shift attenuation, ${}^{59}{Cu}$ deduced levels, $T_{\frac{1}{2}}$ . Enriched target, Ge(Li) detector.]

$E_{p} = 1.118$ MeV resonance in the ${}^{27}{Al} (p, γ) {}^{28}{Si}$ reaction

J. Dalmas, F. Leccia, and M. M. Aléonard

Phys. Rev. C 9, 2200 (1974) - Published 1 June, 1974

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The 12.664-MeV level in ${}^{28}{Si}$ has been populated by resonant proton capture at 1.118 MeV in the ${}^{27}{Al} (p, γ) {}^{28}{Si}$ reaction. $γ$ -ray angular distributions have been measured with a 80- ${cm}^{3}$ Ge(Li) detector. The spin of the 11.432-MeV level is most probably 4 with $T = 0$ ; for the 8.413-MeV level, the assignment $J^{π} = 4^{-}$ is in agreement with the present data. Mixing ratios for $γ$ -ray transitions have been extracted from the angular distributions. Lifetime and branching-ratio studies have been made at $E_{p} = 1.118, 1.724, and 2.876$ MeV. Emphasis was given to measurements on levels at 8.413, 9.702, and 11.577 MeV, as possible candidates for the $4^{-}$ , $5^{-}$ , and $6^{-}$ states of a $K^{π} = 3^{-}$ rotational band based on the 6.879-MeV level. The observed $E 2$ transition strengths are not in agreement with the above assumption. A strength of 0.3 Weisskopf units is found for the 12.664→8.413-MeV $M 1$ transition, which is in conformity with a $J^{π} \to J^{π}$ , $Δ T = 1$ transition in a self-conjugate nucleus; this result may suggest the possibility of another interpretation of these negative-parity states, relied on one-particle - one-hole configurations.

[NUCLEAR REACTION ${}^{27}{Al} (p, γ) {}^{28}{Si}$ , $E_{p} = 1.724, 2.876$ MeV; measured $γ$ -ray branching ratios, Doppler-shift attenuation. $E_{p} = 1.118$ MeV; measured resonance strength, $γ$ -ray branching ratios, mixing ratios, Doppler-shift attenuuation; deduced transition strengths. Natural targets, Ge(Li) detectors.]

Effect of deuteron breakup on elastic deuteron - nucleus scattering

George H. Rawitscher

Phys. Rev. C 9, 2210 (1974) - Published 1 June, 1974

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The properties of the transition matrix elements $V_{ab} (R)$ of the breakup potential $V_{N}$ taken between states $φ_{a} (\vec{r})$ and $φ_{b} (r)$ are examined. Here $φ_{a} (\vec{r})$ are eigenstates of the neutron-proton relative-motion Hamiltonian, and the eigenvalues of the energy $ε_{a}$ are positive (continuum states) or negative (bound deuteron); $V_{N} (\vec{r}, \vec{R})$ is the sum of the phenomenological proton nucleus $V_{p - A} (| \vec{R} - \frac{1}{2} \vec{r} |)$ and neutron nucleus $V_{n - A} (| \vec{R} + \frac{1}{2} \vec{r} |)$ optical potentials evaluated for nucleon energies equal to half the incident deuteron energy. The bound-to-continuum transition matrix element for relative neutron-proton angular momenta $l = 2$ are found to be comparable in magnitude to the ones for $l = 0$ for values of $ε_{a}$ larger than about 3 MeV, and both decrease only slowly with $ε_{a}$ , suggesting that a large breakup spectrum is involved in deuteron-nucleus collisions. The effect of the various breakup transitions on the elastic phase shifts is estimated by numerically solving a set of coupled equations. These equations couple the functions $χ_{a} (\vec{R})$ which are the coefficients of the expansion of the neutron-proton-nucleus wave function in a set of the $φ_{a} (\vec{r})$ 's. The equations are rendered manageable by performing a (rather crude) discretization in the neutron-proton relative-momentum variable $k_{a}$ . Numerical results for 21.6-MeV deuterons incident on Ni and Ca which include only the first momentum bin ( $ε_{a} \leq 10$ MeV) and $l = 0 and 2$ show that the effects on the elastic phase shifts are similar in several respects to those found by Johnson and Soper.

[NUCLEAR REACTIONS Elastic deuteron-nucleus scattering theory. Effect of deuteron breakup. Numerical applications to $E = 21.6$ MeV $d - Ca$ and $d - Ni$ .]

Quasielastic electron scattering

R. R. Whitney, I. Sick, J. R. Ficenec, R. D. Kephart, and W. P. Trower

Phys. Rev. C 9, 2230 (1974) - Published 1 June, 1974

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Data and interpretation are presented for inelastic electron scattering in the quasielastic region from nine target nuclei ranging from lithium to lead at an incident energy of 500 MeV and a scattering angle of 60°. The average kinetic and separation energies of nucleons in these nuclei are deduced. Results of and comments on the radiative correction procedures used in the data analysis are also discussed.

[NUCLEAR REACTIONS ${}^{6}{Li} (e, e^{'})$ , ${}^{12}C (e, e^{'})$ , ${}^{24}{Mg} (e, e^{'})$ , ${}^{40}{Ca} (e, e^{'})$ , ${}^{58.7}{Ni} (e, e^{'})$ , ${}^{89}Y (e, e^{'})$ , ${}^{118.7}{Sn} (e, e^{'})$ , ${}^{181}{Ta} (e, e^{'})$ , ${}^{208}{Pb} (e, e^{'})$ , $E = 500$ MeV, $θ = 60^{\circ}$ ; measured $σ (E)$ ; deduced nucleon separation and kinetic energies in Fermi gas model.]

Decay schemes of ${}^{30}{Al}$ , ${}^{30}P$ , and ${}^{20}O$

D. E. Alburger and D. R. Goosman

Phys. Rev. C 9, 2236 (1974) - Published 1 June, 1974

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${}^{30}{Al}$ was produced in the ${}^{18}O ({}^{18}O, α p n) {}^{30}{Al}$ reaction by bombarding a ${Ta}_{2}$ ${}^{18}O_{5}$ target with 42-MeV ${}^{18}O$ ions. Following transfer of the target in a shuttle system the $γ$ -ray spectrum was measured in a Ge(Li) detector. Nine $γ$ -ray transitions were observed in ${}^{30}{Si}$ and have been fitted to an ${}^{30}{Al}$ decay scheme that includes five $β$ -ray branches to excited states of ${}^{30}{Si}$ . The half-life of ${}^{30}{Al}$ is 3.685±0.032 sec. ${}^{30}P$ was formed in the ${}^{30}{Si} (p, n) {}^{30}P$ reaction and a value of 2.499±0.008 min was obtained for its half-life. The $β^{+}$ branching of ${}^{30}P$ to the 2235-keV first excited state of ${}^{30}{Si}$ was found to be (0.061±0.006)%, differing from previous results. ${}^{20}O$ , formed in the ${}^{18}O$ ( ${}^{18}O$ , ${}^{16}O$ ) ${}^{20}O$ reaction, was also studied and upper limits were placed on various $β$ -decay branches. The half-life of ${}^{20}O$ was measured as 13.49±0.05 sec. $ft$ values for the $β$ decay of ${}^{30}{Al}$ , ${}^{30}P$ , and ${}^{20}O$ are compared with recent theoretical calculations.

[RADIOACTIVITY ${}^{30}{Al}$ , ${}^{30}P$ , ${}^{20}O$ : measured $T_{\frac{1}{2}}$ , $I_{γ}$ ; deduced decay schemes, $log ft$ ; compared with theory.]

Recoil corrections in heavy-ion-induced transfer

A. J. Baltz and S. Kahana

Phys. Rev. C 9, 2243 (1974) - Published 1 June, 1974

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A perturbative approach for rapid calculation of recoil corrections to heavy-ion distorted- wave Born approximation has been developed. Without making either the local momentum approximation or the Hankel function approximation, we expand the final scattering wave function about ${\vec{r}}_{f} = α {\vec{r}}_{i}$ . We have modified the existing no-recoil code RDRC to include exactly the first-order term, allowing one to correct for both longitudinal and transverse recoil effects. Sample calculations have been performed, including an analytically solvable test case, plus the reactions ${}^{94}{Mo}$ ( ${}^{13}C$ , ${}^{12}C$ ) ${}^{95}{Mo}$ and ${}^{48}{Ca}$ ( ${}^{14}N$ , ${}^{13}C$ ) ${}^{49}{Sc}$ for which data have been taken and analyzed previously with RDRC. The relative $α$ independence of the results argues strongly for convergence.

[NUCLEAR REACTIONS ${}^{48}{Ca}$ ( ${}^{14}N$ , ${}^{13}C$ ), $E = 30, 50, 70$ MeV; ${}^{94}{Mo}$ ( ${}^{13}C$ , ${}^{12}C$ ), $E = 48.5$ MeV; calculated proper first-order recoil DWBA. $Q$ , $L$ , and $α$ (scaling parameter) dependence of calculated $σ$ .]

Isomeric state in ${}^{74}{Ga}$

J. van Klinken and L. M. Taff

Phys. Rev. C 9, 2252 (1974) - Published 1 June, 1974

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A 9.5-s activity with an isomeric transition of unusually low energy (3.2 keV) and a subsequent transition of 56.5 keV has been assigned to ${}^{74}{Ga}^{m}$ . The activity has been produced by 14-MeV neutrons in samples of ${}^{74}{Ge}$ . Since this target nucleus has an abundance of 37% in natural germanium, summing of the 3.2- and 56.5-keV transitions could be observed by neutron activation of a Ge detector. Further experiments utilized fast transport and analysis of x rays, $β$ rays, and sum peaks. Combining the results with recent information on the decay of ${}^{74}{Zn}$ , spins and parities could be proposed for levels of ${}^{74}{Ga}$ at 56.5, 59.7, 108.6, and 250.0 keV. For the ground state we propose $J^{π} = 4^{-}$ , which is in contrast with previous suggestions of $3^{-}$ based on analogy to the neighbouring isotopes ${}^{72}{Ga}$ and ${}^{76}{Ga}$ .

[RADIOACTIVITY ${}^{74}{Ga}^{m}$ ; assignment, measured $T_{\frac{1}{2}}$ , $E_{γ}$ , $\frac{σ_{m}}{σ_{g}}$ , x rays. Sum peak in an activated Ge detector. Deduced levels, $J$ , $π$ . Calculated $jj$ coupling.]

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Lifetime limits for the ${}^{46}{Ca}$ $2_{1}^{+}$ (1.35-MeV) and $0_{2}^{+}$ (2.42-MeV) states

Triton binding energies with two-body radial-distortion unitary transforms

$A = 9$ isospin quartet

Unitary pole expansion applied to the trinucleon problem

Survey of the nuclear-matter properties of the Graz potential

Proton form factor from 0.15 to 0.79 ${fm}^{- 2}$

$T = \frac{3}{2}$ states in mass-11 nuclei

Production of Li and B in proton and alpha-particle reactions on ${}^{14}N$ at low energies

Angular distribution and polarization of ${}^{16}O (γ, n_{0}) {}^{15}O$

Elastic and inelastic scattering of ${}^{6}{Li}$ on ${}^{12}C$

Excitation functions for ( $p, n$ ) reactions on ${}^{79}{Br}$ and ${}^{127}I$

Energy dependence of isospin mixing in compound-statistical reactions

Scattering of 9.0-MeV neutrons by Al, Si, Fe, Ni, and Co

Mean lifetimes of levels in ${}^{59}{Cu}$

$E_{p} = 1.118$ MeV resonance in the ${}^{27}{Al} (p, γ) {}^{28}{Si}$ reaction

Effect of deuteron breakup on elastic deuteron - nucleus scattering

Quasielastic electron scattering

Decay schemes of ${}^{30}{Al}$ , ${}^{30}P$ , and ${}^{20}O$

Recoil corrections in heavy-ion-induced transfer

Isomeric state in ${}^{74}{Ga}$

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