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${}^{28}{Si} (n, n^{'} γ)$ photon production cross sections for $E_{γ} = 1.78$ MeV, $5.0 <~ E_{n} <~ 9.5$ MeV

J. K. Dickens and G. L. Morgan

Phys. Rev. C 10, 958(R) (1974) - Published 1 August, 1974

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The excitation function for the production of the 1.78-MeV $γ$ ray due to neutron interactions with ${}^{28}{Si}$ has been measured for incident neutron energies between 5 and 9.5 MeV with neutron energy resolution ∼ 35 keV for $E_{n} = 5$ MeV to ∼ 80 keV for $E_{n} = 9.5$ MeV. These data are compared with previously reported values and with the current ENDF/B evaluation.

NUCLEAR REACTIONS ${}^{28}{Si} (n, n^{'} γ)$ , $E_{n} = 5 - 9$ MeV; measured $γ$ -ray excitation function.

Erratum: Total neutron yield from the ( $α, n$ ) reaction on ${}^{21, 22}{Ne}$

J. K. Bair and F. X. Haas

Phys. Rev. C 10, 961 (1974) - Published 1 August, 1974

Separable potential for the $α - α$ interaction

M. Rahman, D. Husain, and S. Ali

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

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A nonlocal separable interaction of Mongan type has been used to study $S$ -, $D$ -, and $G$ - wave $α - α$ scattering phase shifts up to a bombarding energy of 24 MeV. Calculations have been made in the coordinate representation in which the Coulomb effects have been taken into account exactly. A separable representation of the $α - α$ interaction is found to be satisfactory.

NUCLEAR STRUCTURE $α - α$ interaction; used separable potential to study $S$ -, $D$ -, and $G$ -wave $α - α$ phase shifts.

New treatment of the one-particle continuum in nuclear reaction theory

R. F. Barrett and P. P. Delsanto

Phys. Rev. C 10, 101 (1974) - Published 1 July, 1974

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A new method is proposed for the treatment of the one-particle continuum in nuclear reaction theory. The method comprises a matrix diagonalisation technique similar to that used in the eigenchannel theory. However, in contrast to the eigenchannel theory, this method does not require the $S$ matrix to be obtained in a diagonal form. It is shown that by a relaxation of this requirement, a numerically much faster method of treating the one-particle continuum can be developed.

Faddeev approach to pion production and pion-deuteron scattering

I. R. Afnan and A. W. Thomas

Phys. Rev. C 10, 109 (1974) - Published 1 July, 1974

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Some consequences of a new approach to pion production are explored in the threshold region. We treat the $π NN$ system as a three-body system, with absorption (or production) occurring because of the existence of a $π N$ bound state in the $P_{11}$ (nucleon) channel. This description of the $NN π$ vertex is justified by successfully using the model to calculate the long range part of the $N - N$ scattering amplitude. The results of the pion production calculation confirm a sensitivity to the short range behavior of the deuteron wave function and its $D$ -state probability reported earlier. We also find a stronger variation of the production amplitude with energy than has previously been reported. This may resolve the apparent incompatibility of some experimental results. Finally, we also discuss the implications of the model for pion-deuteron elastic scattering.

NUCLEAR REACTIONS $pp \to π^{+} d$ , $E_{π} = 0 - 30$ MeV; $s$ -wave pions, calculated $σ$ as function of $E_{π}$ , also dependence on $N - N$ interaction. $d (π, π)$ ; calculated scattering length, including absorption. Faddeev calculation, separable interactions.

Inelastic electron scattering and the structure of shell-model nuclei: The ${}^{40}{Ca}$ case

P. Federman and T. W. Donnelly

Phys. Rev. C 10, 12 (1974) - Published 1 July, 1974

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Inelastic electron scattering is shown to be a very powerful tool to study the structure of shell-model nuclei, since the form factors are very sensitive to small admixtures of different orbitals. For instance in our ${}^{40}{Ca}$ case admixtures of only 1% $1 p_{\frac{3}{2}}$ orbital in the pure $f_{\frac{7}{2}}$ orbital produce strong changes in the form factors. Thus, inelastic electron scattering will shed light on the question of "deformed states" in ${}^{40}{Ca}$ . Also it is pointed out that "effective" multipole matrix elements can be extracted. In turn, those matrix elements can be used for structure analysis of shell-model nuclei by giving information on which admixtures should be included to reproduce them.

NUCLEAR STRUCTURE ${}^{40}{Ca}$ ; calculated form factors for inelastic electron scattering.

Analytic solutions in configuration space representation for scattering from a class of separable nonlocal potentials

B. Bagchi and B. Mulligan

Phys. Rev. C 10, 126 (1974) - Published 1 July, 1974

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In this paper we consider scattering of all partial waves from a wide class of separable nonlocal potentials and obtain in configuration space exact analytic expressions for the wave functions and phase shifts. These expressions simplify some of the difficulties associated with finding a potential which fits phase shift data, with the analytic expressions for the scattering length and effective range being particularly useful. Employing these results, we obtain a two-term separable nonlocal potential with three adjustable parameters which gives a reasonable fit to the ${}^{1}S_{0} n - p$ phase shifts and a very good scattering length and effective range.

NUCLEAR REACTIONS Separable nonlocal potentials. Analytic expressions for wave functions, phase shifts. ${}^{1}S_{0} (n - p)$ phase shift fit.

Nuclear structure of ${}^{46}K$ : Studies with ${}^{48}{Ca} (d, α γ) {}^{46}K$ and deuteron-transfer reactions

W. W. Daehnick, J. H. Orloff, T. Canada, and T. S. Bhatia

Phys. Rev. C 10, 136 (1974) - Published 1 July, 1974

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The reactions ${}^{48}{Ca} (d, α) {}^{46}K$ and ${}^{48}{Ca} (d, α γ)$ were studied at $E_{d} = 17 and 7$ MeV, respectively. Angular distributions for the ${}^{48}{Ca} (d, α)$ reaction were obtained in 5° steps from $θ_{lab} = 10 °$ to $θ_{lab} = 145 °$ . Data for $θ \leq 60 °$ were taken with a split-pole spectrograph with resolutions of 13-25 keV. Only the levels at 0, 0.587, 0.691, 0.886, 1.370, 1.738, and 1.941 MeV were seen significantly above background. Excitation functions for $16 \leq E_{d} \leq 17$ MeV at $θ = 90 and 100 °$ showed energy dependent cross section variations of ≲ ± 15% for the ground state and 0.587 MeV level, larger ones for the 1.738 MeV state and negligible variations for the 0.691, 0.886, and 1.941 MeV levels. The level energies listed were also deduced from the fast $α - γ$ coincidence spectra which also served to set independent spin limits. A simultaneous microscopic distorted wave Born approximation analysis for the ( $d, α$ ) data and the ${}^{48}{Ca} (p, {}^{3}{He})$ and ${}^{48}{Ca} (p, t) {}^{46}{Ca}$ ( $T = 4$ ) cross sections previously studied at $E_{p} = 42$ MeV was performed. Under the assumption that ${}^{48}{Ca}$ is doubly magic theoretical and empirical wave functions for the six low-lying negative parity states of ${}^{46}K$ were deduced and used to derive empirical ${(s_{\frac{1}{2}} f_{\frac{7}{2}})}^{2}$ , ${(d_{\frac{3}{2}} f_{\frac{7}{2}})}^{2}$ , and ( $s_{\frac{1}{2}} f_{\frac{7}{2}}, d_{\frac{3}{2}} f_{\frac{7}{2}}$ ) residual $n - p$ interaction matrix elements. The ${}^{48}{Ca} (d, α)$ reaction at 17 MeV, as well as the ${}^{48}{Ca} (p, {}^{3}{He})$ and the ${}^{48}{Ca} (p, t)$ transitions at $E_{p} = 42$ MeV show some features that cannot be explained by one-step direct two-nucleon transfer. The excitation of unnatural parity states in ${}^{48}{Ca} (p, t) {}^{46}{Ca}$ ( $T = 24$ ) and the importance of $L > j - 1$ transitions for the corresponding states in ${}^{46}K$ point to significant two-step contributions. Similarly, the triplet ( $Δ S = 1$ ), ( $Δ T = 0$ ) transfers in ( $p, {}^{3}{He}$ ) are underpredicted with respect to singlet transfers.

NUCLEAR REACTIONS Measured ${}^{48}{Ca} (d, α γ) {}^{46}K$ fast $α - γ$ coincidence spectra, $E_{d} = 7$ MeV, resolution 4-8 keV. Deduced ${}^{46}K$ level energies, $J$ limits. Measured ${}^{48}{Ca} (d, α) {}^{46}K$ , $σ (θ, E)$ , $E_{d} = 17.0$ MeV, resolution 13-30 keV. Microscopic DWBA analysis for ${}^{48}{Ca} (d, α)$ , ${}^{48}{Ca} (p, {}^{3}{He})$ , and ${}^{48}{Ca} (p, t) {}^{46}{Ca}$ ( $T = 4$ ).

Deduced: $J^{π}$ values, ${}^{46}K$ wave functions, residual interaction matrix elements.

Spallation of copper by high-energy alpha particles

Paul J. Karol

Phys. Rev. C 10, 150 (1974) - Published 1 July, 1974

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28 radionuclides produced by spallation of natural copper by 720 MeV $α$ particles were investigated by direct $γ$ counting of irradiated targets. Although the isobaric yield distributions and mass yield curve are similar in many respects to those found in proton spallation, a suppression of yields of neutron deficient products is observed. Several interpretations of this latter phenomenon are critically discussed.

NUCLEAR REACTIONS $Cu (α, spallation)$ , $E = 410, 720$ MeV; measured formation cross sections 28 radionuclides, direct $γ$ counting, natural target.

Interaction of 28-GeV protons with tantalum: Charge dispersion and mass yields of light rare-earth nuclides

Y. Y. Chu, E. M. Franz, and G. Friedlander

Phys. Rev. C 10, 156 (1974) - Published 1 July, 1974

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Independent and cumulative yields of 24 light rare-earth nuclides between mass 143 and mass 157 produced in the interaction of 28-GeV protons with tantalum have been measured. Charge dispersion (CD) curves for masses 146, 148, and 149 have been constructed based on the results obtained from this work with the aid of some previously published data. The importance of feeding by $α$ decay is discussed in detail. The difference between the position of the peak of the CD curve and that of $β$ stability $Z_{p} - Z_{A}$ appears to decrease from ∼3.4 at $A = 146 to \sim 2.5$ at $A = 149$ . The total yields at these masses and at $A = 123$ were evaluated from measured yields and CD curves. The trend of the mass yields over this range is a monotonic decrease with decreasing mass, consistent with a spallation mechanism. Comparison with Rudstam's spallation systematics shows fair agreement regarding the shapes of the CD and mass-yield curves, but with Rudstam's parameter choices the cross sections are overestimated and the $Z_{p} - Z_{A}$ values are not accurately reproduced. Comparison is made between the CD curves obtained in this work and those previously reported for $U$ interactions. The observations are consistent with the interpretation that the light rare-earth products from tantalum results from a spallation-like process, whereas there must be some fission contribution to the slightly neutron-deficient nuclides produced from uranium.

NUCLEAR REACTIONS ${}^{181}{Ta} (p, spallation)$ , $E_{p} = 28$ GeV; measured $σ (A; Z)$ for light rare-earth nuclides.

Interaction of ${}^{238}U$ with 300- and 11.5-GeV protons: Cross sections and recoil properties in the $A \sim 130$ mass region

Y. W. Yu and N. T. Porile

Phys. Rev. C 10, 167 (1974) - Published 1 July, 1974

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Formation cross sections and thick-target recoil properties of 13 products in the $A \sim 130$ mass region from the interaction of ${}^{238}U$ with 300- and 11.5-GeV protons have been determined. The values of $\frac{σ_{300}}{σ_{11.5}}$ are consistent with unity for $A > 130$ and decrease with decreasing $A$ below this mass number, a trend that is most notably exhibited by neutron deficient iodine nuclides. The recoil ranges and $\frac{F}{B}$ values are essentially the same at both energies.

NUCLEAR REACTIONS Measured $σ$ , $2 W (F + B)$ , $\frac{F}{B}$ of 13 I, Cs, and Ba nuclides from 300- and 11.5-GeV proton bombardment of ${}^{238}U$ .

Neutron inelastic scattering from ${}^{91}{Zr}$

S. S. Glickstein and G. Tessler

Phys. Rev. C 10, 173 (1974) - Published 1 July, 1974

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$γ$ -ray production cross sections produced via the ${}^{91}{Zr} (n, n^{'} γ)$ reaction have been measured up to 6.19-MeV neutron energy at an angle of 55° to the incident neutron beam. Neutrons were produced from solid tritium and gaseous deuterium targets using the 3-MeV Bettis Van de Graaff accelerator. The $γ$ rays observed at energies of 652, 660, 713, 726, 792, 796, 1151, 1204.7, 1466.4, 1882.2, 2042.5, 2131.4, 2169.7, 2190.1, 2200.7, and 2367 keV were detected with a 55- ${cm}^{3}$ Ge(Li) detector (3-keV resolution) placed inside a NaI annulus to suppress Compton events. The data have been corrected for multiple scattering and neutron flux attenuation in the sample. Angular distributions have been calculated and used to obtain the total $γ$ -ray production cross section. The data are in good agreement with the results of Hauser-Feshbach calculations corrected for width fluctuations.

NUCLEAR REACTIONS ${}^{91}{Zr} (n, n^{'} γ)$ , $E = 1.27 - 6.19$ MeV; measured and calculated $σ (E, γ)$ ; observed $γ$ -ray production with Ge(Li) detector.

One-proton transfer reactions induced by ${}^{16}O$ and ${}^{12}C$ on ${}^{64}{Ni}$

A. Cunsolo, M. C. Lemaire, M. C. Mermaz, H. Sztark, K. S. Low, and T. Tamura

Phys. Rev. C 10, 180 (1974) - Published 1 July, 1974

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The ( ${}^{16}O$ , ${}^{15}N$ ) and ( ${}^{12}C$ , ${}^{11}B$ ) reactions on ${}^{64}{Ni}$ target have been investigated using 56 MeV ${}^{16}O$ and 48 MeV ${}^{12}C$ beams. Angular distributions were obtained for the first five excited states of ${}^{65}{Cu}$ . No-recoil distorted-wave Born-approximation (DWBA) analyses were made and striking anomalies were found especially for the ( ${}^{16}O$ , ${}^{15}N$ ) reaction leading to the $j_{<}$ states. These anomalies were then shown to disappear if exact finite-range DWBA analyses were made, which gave reasonable absolute spectroscopic coefficients in close agreement with those obtained in light ion reactions.

NUCLEAR REACTIONS ${}^{64}{Ni}$ ( ${}^{16}O$ , ${}^{16}O$ ), ( ${}^{16}O$ , ${}^{15}N$ ), $E = 56$ MeV; ${}^{64}{Ni}$ ( ${}^{12}C$ , ${}^{12}C$ ), ( ${}^{12}C$ , ${}^{11}B$ ), $E = 48$ MeV; resolution = 250 and 200 keV, enriched target, $θ = 15 - 65 °$ , $Δ θ ≃ 5 °$ . Measured $σ (θ)$ , deduced optical model parameters; no-recoil and exact finite range DWBA, ${}^{65}{Cu}$ levels deduced $S$ .

Treatment of large perturbations of the Hamiltonian and the boundary conditions in scattering and reaction calculations

R. B. Perez and G. de Saussure

Phys. Rev. C 10, 187 (1974) - Published 1 July, 1974

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On the basis of an integrodifferential equation which was derived in a previous work for the $T$ matrix of nuclear reaction theory, we have developed a general formalism to treat large perturbations in both the Hamiltonian and the boundary conditions of a quantum mechanical system. As a result of this formalism, a set of first order differential equations, in terms of any of the physical parameters of the system, is given for the widths and poles of the collision $U$ matrix. The technique is illustrated by the conversion of a set of $R$ -matrix resonance parameters into its equivalent set of $U$ -matrix widths and poles, which corresponds to the passage from the $R$ -matrix boundary conditions to the complex, momentum-dependent boundary conditions associated with the Kapur-Peierls reaction formalism. The case of large perturbations of the Hamiltonian is illustrated by the calculation of the elastic and inelastic scattering cross sections in a strongly coupled two-channel system which was proposed by Tobocman and has been widely used as testing grounds for reaction theories.

Parametrization of $σ_{tot}$ , $σ (θ)$ , and $P (θ)$ for 25-100 MeV $n p$ elastic scattering

Judith Binstock

Phys. Rev. C 10, 19 (1974) - Published 1 July, 1974

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We present a parametrization of the ${}^{1}H (n, n) {}^{1}H$ total cross section, differential cross section, and polarization, for the neutron lab kinetic energy range 25-100 MeV. The observables we parametrized are computed from the phase shifts of the Bryan-Gersten potential-model constrained fit to all of the available 0-450 MeV $n p$ and $p p$ elastic scattering data. We find our parametrization of $σ (θ)$ to differ significantly from the Gammel formula, in that for all energies 25-100 MeV we have higher $\frac{σ (180 °)}{σ (90 °)}$ ratios, as well as $σ (θ)$ shapes which are nonsymmetric about 90° c.m. Our total cross sections begin to differ from the Gammel formula at neutron energies above 50 MeV, where the Gammel formula was never meant to apply anyway.

NUCLEAR REACTIONS ${}^{1}H (n, n)$ , $E = 25 - 100$ MeV; parametrized $σ (E)$ , $σ (E; θ)$ , $P (E, θ)$ .

Fission and complete-fusion probabilities as a function of angular momentum for ${}^{170}{Yb}$ compound nuclei excited to 107 MeV

A. M. Zebelman, L. Kowalski, J. Miller, K. Beg, Y. Eyal, G. Jaffe, A. Kandil, and D. Logan

Phys. Rev. C 10, 200 (1974) - Published 1 July, 1974

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Fission and complete-fusion cross sections are presented for four entrance channels leading to ${}^{170}{Yb}$ compound nuclei excited to 107 MeV: ${}^{11}B$ + ${}^{159}{Tb}$ , ${}^{12}C$ + ${}^{158}{Gd}$ , ${}^{16}O$ + ${}^{154}{Sm}$ , and ${}^{20}{Ne}$ + ${}^{150}{Nd}$ . The measured fission cross sections are 5.9 ± 0.6, 16. ± 2., 40. ± 4., and 89. ± 9. mb for the ${}^{11}B$ , ${}^{12}C$ , ${}^{16}O$ , and ${}^{20}{Ne}$ entrance channels, respectively. The completefusion cross sections for these same entrance channels are 980 ± 150, 1100 ± 160, 1260 ± 190, and 1450 ± 220 mb. The data are combined using a technique which yields the dependence of fission probability over three relatively narrow ranges of angular momentum. The results of the analysis just described are compared to a calculation based on the Bohr-Wheeler formalism for fission widths and the Weisskopf formalism for neutron and charged-particle widths. The calculations include the effects of multiple chance fission but assume that second and higher chance fission is nonnegligible only if preceded by neutron emission rather than charged particle emission. Agreement between the experimental results and the theoretical calculations is found for a ratio of level density parameters for the compound nucleus and the saddle point equal to 1.2 ± 0.1. Fission-fragment angular distributions for the four entrance channels are presented and compared to calculations

NUCLEAR REACTIONS, COMPLETE FUSION, FISSION ${}^{159}{Tb}$ ( ${}^{11}B$ , ${}^{170}{Yb}$ *), $E = 115$ MeV; ${}^{158}{Gd}$ ( ${}^{12}C$ , ${}^{170}{Yb}$ *), $E = 126$ MeV; ${}^{154}{Sm}$ ( ${}^{16}O$ , ${}^{170}{Yb}$ *), $E = 137$ MeV; ${}^{150}{Nd}$ ( ${}^{20}{Ne}$ , ${}^{170}{Yb}$ *), $E = 144$ MeV; measured $σ (θ)$ for evaporation residues and fission fragments, deduced $J_{CRIT}$ , $Γ_{f}$ .

Measurement of the ${}^{11}B$ + ${}^{159}{Tb}$ complete-fusion cross section

R. L. Kozub, D. Logan, J. M. Miller, and A. M. Zebelman

Phys. Rev. C 10, 214 (1974) - Published 1 July, 1974

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The complete-fusion cross section for the ${}^{170}{Yb}$ compound system, formed in the reaction of 115 MeV ${}^{11}B$ with ${}^{159}{Tb}$ , has been measured using a counter telescope containing a thin gas proportional counter and a Si surface-barrier detector. The result is in excellent agreement with that obtained using mica track detectors.

NUCLEAR REACTIONS Complete fusion ${}^{159}{Tb}$ ( ${}^{11}B$ , ${}^{170}{Yb}$ *), $E = 115$ MeV; measured $σ (θ)$ for evaporation residues.

Accurate elastic scattering cross sections for 17-MeV deuterons

J. D. Childs, W. W. Daehnick, and M. J. Spisak

Phys. Rev. C 10, 217 (1974) - Published 1 July, 1974

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Angular distributions for 17.0-MeV ( $d, d$ ) scattering on 23 isotopically pure targets ( ${}^{27}{Al}$ , ${}^{48}{Ca}$ , ${}^{51}V$ , ${}^{52}{Cr}$ , ${}^{54}{Fe}$ , ${}^{56}{Fe}$ , ${}^{59}{Co}$ , ${}^{58}{Ni}$ , ${}^{62}{Ni}$ , ${}^{64}{Ni}$ , ${}^{68}{Zn}$ , ${}^{89}Y$ , ${}^{93}{Nb}$ , ${}^{100}{Mo}$ , ${}^{105}{Pd}$ , ${}^{112}{Cd}$ , ${}^{115}{In}$ , ${}^{112}{Sn}$ , ${}^{120}{Sn}$ ${}^{124}{Sn}$ , ${}^{208}{Pb}$ , ${}^{209}{Bi}$ , ${}^{232}{Th}$ ) have been measured from $θ_{lab} \leq 10 to 165 °$ in 5° steps. Relative experimental errors are always less than 2% and absolute scale errors range from 2 to 5%. Optical model searches have been performed on all angular distributions. Good fits were obtained (with four free parameters) for three values of the real radius parameter $r_{0} = 1.0, 1.1, and 1.2$ fm using starting values of $V_{0} \approx 100$ MeV. The best fit parameters are presented for these searches, as well as for the best over-all nine-parameter fits. The data show some preference for parameter values close to $r_{0} = 1.1$ fm (with $a \approx 0.82$ ) for all targets heavier than ${}^{48}{Ca}$ , although very acceptable fits are also obtained for all three sets with restricted parameters. The searches with nine free parameters resulted in overly perfect fits ( $χ^{2} ≲ 1$ ) indicative of considerable ambiguity for so large a parameter space. Preliminary global fits to our 17-MeV data yielded a formula for generating usable optical model parameters for other near-spherical nuclei of mass $A > 48$ .

NUCLEAR REACTIONS ${}^{27}{Al}$ , ${}^{48}{Ca}$ , ${}^{51}V$ , ${}^{52}{Cr}$ , ${}^{54}{Fe}$ , ${}^{56}{Fe}$ , ${}^{59}{Co}$ , ${}^{58}{Ni}$ , ${}^{62}{Ni}$ , ${}^{64}{Ni}$ , ${}^{68}{Zn}$ , ${}^{89}Y$ , ${}^{93}{Nb}$ , ${}^{100}{Mo}$ , ${}^{105}{Pd}$ , ${}^{112}{Cd}$ , ${}^{115}{In}$ , ${}^{112}{Sn}$ , ${}^{120}{Sn}$ , ${}^{124}{Sn}$ , ${}^{208}{Pb}$ , ${}^{209}{Bi} (d, d)$ , $E = 17.00$ MeV, measured $σ (θ)$ and ${}^{232}{Th} (d, d^{'})$ , $E = 17.00$ MeV, measured $σ (E_{d}, θ)$ optical model analysis, deduced $A$ dependence in optical model parameter prescription. Enriched targets.

Absolute cross sections for proton-induced fission of the uranium isotopes

J. R. Boyce, T. D. Hayward, R. Bass, H. W. Newson, E. G. Bilpuch, F. O. Purser, and H. W. Schmitt

Phys. Rev. C 10, 231 (1974) - Published 1 July, 1974

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Absolute cross sections for proton induced fission have been measured for ${}^{233}U$ , ${}^{234}U$ , ${}^{235}U$ , ${}^{236}U$ , and ${}^{238}U$ for proton energies ranging from 5.0 to 30.0 MeV. Angular distributions have been measured for all isotopes and the fission fragment angular anisotropy determined as a function of excitation energy. Excitation data were accumulated at 250 keV intervals with smaller steps in regions of special interest. Fission probabilities calculated from the data and optical model predictions prominently display effects due to the opening of additional fission channels as excitation energy is increased. A method of analysis is formulated and demonstrated which makes use of the extended energy range and selection of an isotopic sequence of target nuclei to unfold the contributions to the measured cross section from first, second, and third chance fission. Using this method, previously undetermined fission thresholds and $\frac{Γ_{n}}{Γ_{f}}$ ratios are estimated for individual nuclei as functions of excitation energy.

NUCLEAR REACTIONS, FISSION ${}^{233}U (p, x n f)$ , ${}^{234}U (p, x n f)$ , ${}^{235}U (p, x n f)$ , ${}^{236}U (p, x n f)$ , and ${}^{238}U (p, x n f)$ , $E = 5.0 - 30.0$ MeV; measured $σ_{p, x n f} (E_{p}, θ)$ ; deduced $σ_{fT} (E)$ , $\frac{Γ_{n}}{Γ_{f}} (E, A)$ , fission barriers.

Particle configurations of giant $E 1$ states in the ${}^{14}N (γ, p_{2})$ and ${}^{14}N (γ, p_{0})$ processes

J. E. E. Baglin, E. J. Bentz, and R. W. Carr

Phys. Rev. C 10, 24 (1974) - Published 1 July, 1974

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Angular distributions and absolute cross sections have been measured for the ${}^{14}N (γ, p_{2})$ and ${}^{14}N (γ, p_{0})$ reactions, at giant resonance energies. The angular distributions are shown to be consistent with a model in which exclusively ${(p_{\frac{1}{2}})}^{- 1} (2 s 1 d)$ giant dipole states populate the ${}^{13}C$ ground state by proton decay, and predominantly ${(p_{\frac{3}{2}})}^{- 1} (2 s 1 d)$ giant dipole states feed the ${\frac{3}{2}}^{-}$ state of ${}^{13}C$ at 3.68 MeV. Branching calculations based on established spectroscopic factors further support this model. It is inferred that the ${}^{14}N$ dipole states of ${(p_{\frac{3}{2}})}^{- 1} (2 s 1 d)$ character, which carry ∼90% of the $E 1$ strength and which dominate the ( $γ, p_{2}$ ) process studied, do not contribute significantly to the ( $γ, p_{0}$ ) process which has often previously been treated as representative of $E 1$ absorption.

NUCLEAR REACTIONS ${}^{14}N (γ, p_{2})$ , ( $γ, p_{0}$ ), $E_{γ} = 19 - 25$ MeV; measured $σ (E_{γ}; E_{p}; θ)$ . Deduced $E 2$ , $M 1$ excitation strength. Inferred parent $E 1$ configurations.

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Physical Review C

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${}^{28}{Si} (n, n^{'} γ)$ photon production cross sections for $E_{γ} = 1.78$ MeV, $5.0 <~ E_{n} <~ 9.5$ MeV

Erratum: Total neutron yield from the ( $α, n$ ) reaction on ${}^{21, 22}{Ne}$

Separable potential for the $α - α$ interaction

New treatment of the one-particle continuum in nuclear reaction theory

Faddeev approach to pion production and pion-deuteron scattering

Inelastic electron scattering and the structure of shell-model nuclei: The ${}^{40}{Ca}$ case

Analytic solutions in configuration space representation for scattering from a class of separable nonlocal potentials

Nuclear structure of ${}^{46}K$ : Studies with ${}^{48}{Ca} (d, α γ) {}^{46}K$ and deuteron-transfer reactions

Spallation of copper by high-energy alpha particles

Interaction of 28-GeV protons with tantalum: Charge dispersion and mass yields of light rare-earth nuclides

Interaction of ${}^{238}U$ with 300- and 11.5-GeV protons: Cross sections and recoil properties in the $A \sim 130$ mass region

Neutron inelastic scattering from ${}^{91}{Zr}$

One-proton transfer reactions induced by ${}^{16}O$ and ${}^{12}C$ on ${}^{64}{Ni}$

Treatment of large perturbations of the Hamiltonian and the boundary conditions in scattering and reaction calculations

Parametrization of $σ_{tot}$ , $σ (θ)$ , and $P (θ)$ for 25-100 MeV $n p$ elastic scattering

Fission and complete-fusion probabilities as a function of angular momentum for ${}^{170}{Yb}$ compound nuclei excited to 107 MeV

Measurement of the ${}^{11}B$ + ${}^{159}{Tb}$ complete-fusion cross section

Accurate elastic scattering cross sections for 17-MeV deuterons

Absolute cross sections for proton-induced fission of the uranium isotopes

Particle configurations of giant $E 1$ states in the ${}^{14}N (γ, p_{2})$ and ${}^{14}N (γ, p_{0})$ processes

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