Distorted-wave calculations using the Johnson and Soper adiabatic deuteron potential have been carried out for the reaction ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}\mathrm{}(p,d)\mathrm{}{}_{}{}^{15}{}_{}{}^{}\mathrm{O}$ at 31.82, 38.63, and 45.34 MeV. The calculated angular distributions describe the data well with no need for a lower radial cutoff. The resultant spectroscopic factors are plausible and relatively independent of energy. Various modifications of the distorted-wave calculations and the sensitivity to different proton and deuteron potentials are investigated.

The $g$ factor of the ${\frac{19}{2}}^{-}$ state in ${}_{}{}^{43}{}_{}{}^{}\mathrm{Sc}$ is discussed within the framework of the conventional shell model. An inert ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ core is assumed. The effective interaction derived for this mass region by Kuo and Brown is used. It is shown that the $g$ factor can be well explained with a small configuration mixing. The $g$ factor of the $6^{+}$ state in ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ca}$ is also discussed.

The neutron total cross sections of natural Be, C, N, O, Mg, Al, and Si have been measured at a number of energies between 24 and 60 MeV. The over-all precision is better than 1% and the energies have been determined to 100 keV. Smooth variations of the cross sections with energy are found.

Interactions of neutrons with aluminum have been studied by measuring $\gamma$-ray-production cross sections. Spectra were obtained for incident mean neutron energies $E_n=5.35, 5.85, 6.4, 6.9, 7.45, 7.95, 8.5, \mathrm{and} 9.0$ MeV. The $\gamma$ rays were detected using a coaxial Ge(Li) detector of 30-${\mathrm{cm}}^3$ active volume. Data were obtained for $\gamma$-ray scattering angles of 55° for all $E_n$, 90° for all $E_n$ except 5.35 MeV, and 75° for $E_n=6.4\mathrm{} \mathrm{and} 7.45$ MeV. Time of flight was used with the detector to discriminate against pulses due to neutrons and background radiation. Absolute cross sections for production of $\gamma$ rays were obtained for the incident neutron energies quoted above. The cross sections have been compared, where possible, with previous measurements with good agreement. The spectra were studied for $\gamma$ rays which could be associated with deexcitation of nuclear levels having unknown decay modes. $\gamma$ rays were found having energies appropriate for ground-state decay of levels at excitation energies $E_x=5.155, 5.414, 5.434, 6.514, 6.821, 6.956, 7.920, 7.411, 7.471, 7.56 \left(\mathrm{doublet}\right), 7.655, 8.148, \mathrm{and} 8.184$ MeV.

Levels of ${}_{}{}^{31}{}_{}{}^{}\mathrm{S}$ above $E_x=4.5\mathrm{}$ MeV have been studied with 18-MeV ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ ions via the neutron-pickup reaction ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}({}_{}{}^3{}_{}{}^{}\mathrm{He},\alpha ){}_{}{}^{31}{}_{}{}^{}\mathrm{S}$. The $\alpha$ particles were detected by position-sensitive counters placed along the focal plane of the spectrograph. The experimental energy resolution was 13-18 keV full width at half maximum and permitted the resolution of some multiplets that previously had been interpreted as single states. Strongly structured angular distributions for nine well-resolved $\alpha$-particle groups were obtained over the angular range $7.5\le \theta \le 45°$. The $l$ values and spectroscopic factors for the transferred neutrons were extracted by comparison with distorted-wave calculations. The apparent absence of the bulk of the $1p$ neutron-pickup strength is discussed.

The ground state and first four excited states of ${}_{}{}^{85}{}_{}{}^{}\mathrm{Br}$ observed in the reaction ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}(d,{}_{}{}^3{}_{}{}^{}\mathrm{He}){}_{}{}^{85}{}_{}{}^{}\mathrm{Br}$ at 0.0, 0.348, 1.169, 1.792, and 2.310 MeV have been assigned spins and parities of ${\frac{3}{2}}^{-}$, ${\frac{5}{2}}^{-}$, ${\left(\frac{3}{2}\right)}^{-}$, ${\left(\frac{1}{2}\right)}^{-}$, and (${\frac{9}{2}}^{+}$), respectively.

We calculate the photodisintegration integrated (${\sigma }_{\mathrm{int}}$) and bremsstrahlung-weighted (${\sigma }_{\mathrm{b}}$) cross sections of the trinucleons (${\mathrm{H}}^3$ and ${\mathrm{He}}^3$) by applying the sum rules of Levinger and Bethe. The ground state of the trinucleon is assumed to be a mixture of symmetric $S$ state, the mixed symmetric $S^{\prime }$ state, and the $D$ states; the radial dependence of all these states being (a) Gaussian and (b) Irving. We obtain the parameters of the radial part of these wave functions from a variational calculation of the binding energy of the triton using the velocity-dependent potential of Nestor et al. Our results for ${\sigma }_{\mathrm{int}}$ show good agreement with experiments.

A comparison with similar calculations using hard-core potentials shows the inability of ${\sigma }_{\mathrm{int}}$ calculations to distinguish between hard-core and velocity-dependent potentials. This feature of ${\sigma }_{\mathrm{int}}$ calculations, which is common at least to all the nuclei in the 1s shell, is explained in terms of the well-known range-depth relationship for the two-body potentials.

Magnetic transitions in ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}$ have been investigated by 180° electron scattering from an isotopically enriched gaseous target at energies of 39 and 56 MeV. As in the case of ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$, considerable fragmentation of the magnetic dipole strength is evident. Magnetic dipole transitions are observed at 10.05 and 11.25 MeV with ground-state transition widths of 6.2 and 8.9 eV, respectively. A magnetic quadrupole transition is observed at 8.44 MeV with a ground-state transition width of 10.6 × ${10}^{-3\mathrm{}}$ eV. Two possible magnetic quadrupole transitions and one possible magnetic dipole transition are observed at 7.46, 11.58, and 12.09 MeV, respectively. Ambiguous results were obtained as to the multipolarity of two transitions at 9.27 and 10.55 MeV. The experimental results are discussed in terms of the theory of Kurath.

Elastic electron scattering from the stable even-even Zn isotopes was measured in the region of the first diffraction minimum ($0.3\le q\le 1.1$ ${\mathrm{fm}}^{-\mathrm{t}}$). The cross-section ratios for each pair of isotopes were used to determine the change in the rms radius. The rms radius follows an $A^{\frac{1}{3}}$ law between ${}_{}{}^{64}{}_{}{}^{}\mathrm{Zn}$ and ${}_{}{}^{66}{}_{}{}^{}\mathrm{Zn}$ and between ${}_{}{}^{68}{}_{}{}^{}\mathrm{Zn}$ and ${}_{}{}^{70}{}_{}{}^{}\mathrm{Zn}$: whereas, between ${}_{}{}^{66}{}_{}{}^{}\mathrm{Zn}$ and ${}_{}{}^{68}{}_{}{}^{}\mathrm{Zn}$ the rms radius decreases significantly.

The ${\beta }^{-}$ decay of ${\mathrm{Cl}}^{39}$ to states of ${\mathrm{Ar}}^{39}$ has been studied using a Ge(Li) detector. ${\mathrm{Cl}}^{39}$ was produced in the reaction ${\mathrm{Cl}}^{37}\mathrm{}(t,p)\mathrm{}{\mathrm{Cl}}^{39}$ at $E_t=3.0\mathrm{}$ MeV by bombarding Ba${\mathrm{Cl}}_2$ targets enriched to 96.1% in ${\mathrm{Cl}}^{37}$. The half-life was measured to be 56.2 ± 0.6 min. Ten $\gamma$-ray transitions were observed including seven $\gamma$ rays not seen previously in the ${\mathrm{Cl}}^{39}$ decay. Ge(Li) versus NaI(Tl) coincidence measurements were used to determine the placement of these $\gamma$-ray transitions in the ${\mathrm{Ar}}^{39}$ level scheme. The measured $\gamma$-ray intensities determine new $\beta$-ray branches of ≤0.08%, (2.61 ± 0.11)%, (2.29 ± 0.12)%, and (0.60 ± 0.05)% to ${\mathrm{Ar}}^{39}$ levels at 2093, 2358, 2503, and 2829 keV with $\mathrm{lof}\mathrm{ft}$ values of ≥8.03, 6.14 ± 0.04, 5.96 ± 0.04, and 5.84 ± 0.06, respectively. The latter two $log\mathrm{ft}$ values lead to spin restrictions of $\frac{1}{2}$, $\frac{3}{2}$, or $\frac{5}{2}$ for the 2305- and 2829-keV ${\mathrm{Ar}}^{39}$ levels and strongly suggest even parity for both states. Other previously observed $\beta$-ray branches have been confirmed. Accurate excitation energies with errors between 0.05 and 1.0 keV have been obtained for the ${\mathrm{Ar}}^{39}$ states involved.

The decay scheme of the ground state of ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$ has been reexamined by measurement of its $\gamma$-ray spectrum with Ge(Li) detectors. The $\gamma$-ray spectrum shows very strong positron annihilation radiation, a strong peak at 1808.65 ± 0.07 keV, a weak peak at 1129.67 ± 0.10 keV, and a very weak peak at 2938 keV. These $\gamma$-ray energies correspond to transitions from the first and second excited states of ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$, which have been determined more accurately in this experiment. The ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$ branching ratios, calculated from the $\gamma$-ray relative intensities, are (82.1 ± 2.5)% positron emission to the 1809-keV level, (15.2 ± 2.5)% electron capture to that same level, and (2.7 ± 0.2)% electron capture to the 2938-keV level of ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$. The 2938-keV state decays (10.2 ± 2.0)% directly to the ground state and (89.8 ± 2.0)% by cascade. These branching ratios combine with previous results to give a half-life of (7.16 ± 0.32) × ${10}^5$ yr for the ground state of ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$.

A self-consistent procedure is outlined in which the interaction radius $R$ of the surface $\delta$ interaction (SDI) is determined self-consistently from the spherical Hartree-Fock-Bogoliubov (HFB) field it produces. It is shown that if the surface $R$ is determined this way, the Woods-Saxon single-particle wave functions are more or less equal in magnitude at $R$, as assumed in earlier works. The procedure is also shown to give numerical results for quasiparticle energies in Ni isotopes in agreement with experimental indications. Thus, the SDI model provides us with an example where the effective interaction is self-consistently determined with the field it produces.

Levels of ${}_{}{}^{50}{}_{}{}^{}\mathrm{Mn}$ were observed via the ${}_{}{}^{50}{}_{}{}^{}\mathrm{Cr}({}_{}{}^3{}_{}{}^{}\mathrm{He},t){}_{}{}^{50}{}_{}{}^{}\mathrm{Mn}$ reaction at 39.45-MeV bombarding energy, using the broad-range magnetic spectrograph at the Oak Ridge isochronous cyclotron. Differential cross sections were measured in the angular range from 4 to 56° in 4° intervals. A total of 29 states below 4-MeV excitation in ${}_{}{}^{50}{}_{}{}^{}\mathrm{Mn}$ were identified. A microscopic distortedwave Born-approximation analysis, including a tensor force and assuming pure $f_{\frac{7}{2}}$ configurations, was used to obtain $J^{\pi }$ assignments for nine levels below 2-MeV excitation. Anomalies reported in previous (${}_{}{}^3{}_{}{}^{}\mathrm{He},t$) studies were observed: (1) The interaction strengths required to normalize the fits for natural-parity states increased with $J$; and (2) for the highspin $T_{<}$ states, angular shifts between the theoretical and experimental angular distributions were observed. The energy level scheme is compared with results of ${}_{}{}^{50}{}_{}{}^{}\mathrm{Cr}\mathrm{}(p,n)\mathrm{}{}_{}{}^{50}{}_{}{}^{}\mathrm{Mn}$ and ${}_{}{}^{50}{}_{}{}^{}\mathrm{Cr}(p,n\gamma ){}_{}{}^{50}{}_{}{}^{}\mathrm{Mn}$ experiments, as well as with a theoretical level scheme from shell-model calculations.

Hartree-Fock-Bogoliubov (HFB) calculations are done for some even-even nuclei in the $p-f$ shell taking ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ as a doubly closed core. It is observed that the nuclear shape changes from a prolate to oblate shape, and the pairing correlations increase in the neutron states and decrease in the proton states as one goes from the Ti to the Zn and Ge isotopes. Whether the $f_{\frac{7}{2}}$ shell-closure approximation in which ${}_{}{}^{56}{}_{}{}^{}\mathrm{Ni}$ is taken as a closed core is valid or not is discussed by comparing the calculated occupation probabilities of the $f_{\frac{7}{2}}$ shell and the break in the pair separation energy at ${}_{}{}^{56}{}_{}{}^{}\mathrm{Ni}$ with the experimental values. Projected HFB spectra have been obtained for ${}_{}{}^{64}{}_{}{}^{}\mathrm{Zn}$, ${}_{}{}^{66}{}_{}{}^{}\mathrm{Zn}$, and ${}_{}{}^{70}{}_{}{}^{}\mathrm{Ge}$. Reasonable agreement with the experimental spectra is obtained for ${}_{}{}^{66}{}_{}{}^{}\mathrm{Zn}$ and ${}_{}{}^{70}{}_{}{}^{}\mathrm{Ge}$. The reasons for the failure of the present method in ${}_{}{}^{64}{}_{}{}^{}\mathrm{Zn}$ are discussed.

Differential cross sections for quasielastic ($p,n$) scattering from 17-20-MeV bombarding energies have been measured for Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Se, Zr, and Nb in either 7.5 or 15° steps between 3 and 157.5°. A complex isospin-dependent potential, whose strengths and form factors are deduced from the Becchetti and Greenless global neutron and proton optical potentials, gave a good over-all description of the average behavior for the 17-20-MeV quasielastic ($p,n$) data. In particular, volume real and surface imaginary isospin form factors with strengths of 96 and 48 MeV, respectively, yielded a reasonable fit to both the shape and magnitude of the Fe and Nb quasielastic ($p,n$) data. On the other hand, using a purely real isospin potential requires a surface interaction of strength 126 MeV for Fe and a volume interaction of strength 107 MeV for Nb. The calculations have been extended to 30- and 50-MeV bombarding energy and have been compared with the measurements of Batty et al. At 30 MeV there is good agreement as regards both shape and magnitude; at 50 MeV the shapes are reasonably well described, but the calculated magnitudes are uniformly higher for most of the targets investigated. It is suggested that the 50-MeV data are consistent with a 30% decrease in the isospin strength in going from 30 to 50 MeV.

Low-lying states of ${}_{}{}^{96}{}_{}{}^{}\mathrm{Nb}$ have been studied via the ${}_{}{}^{96}{}_{}{}^{}\mathrm{Zr}(p,n\gamma ){}_{}{}^{96}{}_{}{}^{}\mathrm{Nb}$ reaction. Ge(Li)$\gamma$ spectra were measured in coincidence with neutrons at proton bombarding energies of 3.5 and 4.5 MeV. Five $\gamma$ rays were observed in these spectra and had energies to ± 1 keV of 99, 181, 307, 326, and 450 keV. Two additional $\gamma$ rays with energies of 38 and 43 keV were observed with a Si(Li) detector at $E_p=3.5\mathrm{}$ MeV. $\gamma -\gamma$ coincidence measurements were made with two Ge(Li) detectors to identify the ${}_{}{}^{96}{}_{}{}^{}\mathrm{Nb}$ decay scheme. These measurements suggest that the 38-, 43-, 99-, 181-, 326-, and 450-keV $\gamma$ rays correspond to transitions between the 180→142-, 43 →0-, 142→43-, 687→506-, 506→180-, and 630→180-keV levels in ${}_{}{}^{96}{}_{}{}^{}\mathrm{Nb}$, respectively. $\gamma$ - neutron and $\gamma -\gamma$ timing measurement yielded the following upper limits for mean lifetimes: $\tau (142\mathrm{}-\mathrm{keV}\mathrm{level})<\mathrm{}1.1\mathrm{}$ nsec, $\tau \mathrm{}\left(180\right)<1.1\mathrm{}$ nsec, $\tau \mathrm{}\left(506\right)<0.6\mathrm{}$ nsec, $\tau \mathrm{}\left(630\right)<2\mathrm{}$ nsec, and $\tau \mathrm{}\left(687\right)<2\mathrm{}$ nsec. On the basis of the observed $\gamma$ transitions and their strengths, spin assignments have been made to the previously identified $\left(\pi g_{\frac{9}{2}}\right){\left(\nu d_{\frac{5}{2}}\right)}^{-1\mathrm{}}$ multiplet in ${}_{}{}^{96}{}_{}{}^{}\mathrm{Nb}$. The 0-, 43-, 142-, 180-, and 630-keV states are assigned $J^{\pi }$ values of $6^{+}$, $5^{+}$, $4^{+}$, $3^{+}$, and $2^{+}$, respectively, which leaves the 233-keV state as the $7^{+}$ member; these assignments are based on an assumed $\left(\pi g_{\frac{9}{2}}\right){\left(\nu d_{\frac{5}{2}}\right)}^{-1\mathrm{}}$ structure. These $J^{\pi }$ values are in accord with the tentative spin assignments made in the ${}_{}{}^3{}_{}{}^{}\mathrm{He},t$ study by Comfort et al. These results also agree with those predicted by the Pandya transformation from the known $\left(\pi g_{\frac{9}{2}}\right)\left(\nu d_{\frac{5}{2}}\right)$ multiplet in ${}_{}{}^{92}{}_{}{}^{}\mathrm{Nb}$.

Measurements of the cross sections for the reactions ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}\mathrm{}(p,p)\mathrm{}{}_{}{}^{14}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}(p,{\alpha }_0){}_{}{}^{11}{}_{}{}^{}\mathrm{B}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}(p,n_0){}_{}{}^{14}{}_{}{}^{}\mathrm{N}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}(p,n_1){}_{}{}^{14}{}_{}{}^{}\mathrm{N}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}(p,{\gamma }_0){}_{}{}^{15}{}_{}{}^{}\mathrm{N}$, and ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}(\alpha ,\alpha ){}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ have been made for incident particle energies of 2 to 4 MeV. Preliminary Legendre-polynomial analyses of measured angular distributions were used to guide a multilevel multichannel $R$-matrix analysis. In the $R$-matrix formulation a set of level parameters for eight resonances has been found which can account for the observed cross sections in all of the channels. The level at $E_x=13.42\mathrm{}$ MeV in ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ has been identified as the isobaric analog of the second excited state in ${}_{}{}^{15}{}_{}{}^{}\mathrm{C}$. The reduced widths of this level in the various channels indicate that it contains at least a 10% admixture of $T=\frac{1}{2}$. A series of strong $\alpha$-particle levels has been found which fit into the $\alpha$-particle core-excited threshold-state model scheme for ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$.

Independent-fission yields of ${\mathrm{Nb}}^{95m+g}$, ${\mathrm{Nb}}^{96}$, ${\mathrm{Tc}}^{99m}$, ${\mathrm{Rh}}^{106}$, ${\mathrm{Ag}}^{112}$, ${\mathrm{In}}^{115m}$, ${\mathrm{Cs}}^{134m}$, and ${\mathrm{Cs}}^{135m}$, and fission yields of four mass chains in the symmetric region $A=111\mathrm{}-115$ have been determined in the fission of ${\mathrm{Th}}^{232}$ induced by 14.8-MeV neutrons. Various postulates of charge distribution were tested to correlate the experimental data. It was found that the equal-charge-displacement hypothesis agreed well for the fission products produced by the asymmetric mode of fission, and the constant-charge-ratio postulate showed the best correlation for the fission products produced by the symmetric mode of fission. Evidence for 40- and 50-proton shell effects on the fission yields has been found in this work.

The thermal-neutron-capture $\gamma$-ray spectra from natural Pb and enriched ${\mathrm{Pb}}^{207}$ have been studied with a 20-${\mathrm{cm}}^3$ Ge(Li) detector. A careful comparison of these spectra reveals the existence of two weak $\gamma$-ray cascades (intensity ≅ ${10}^{-3\mathrm{}}$ times the intensity of the primary transition to the ${\mathrm{Pb}}^{208}$ ground state) from the neutron-capture state to the ${\mathrm{Pb}}^{208}$ ground state. These cascades have energies 4753.7-2614.0 keV and 3283.3-4086.0 keV and pass through the first excited $3^{-}$ state at 2614.0 keV and a $2^{+}$ state at 4086.0 keV, respectively. The neutron separation energy of ${\mathrm{Pb}}^{208}$ was measured to be 7367.7 ± 0.7 keV.

Differential cross sections for elastic and inelastic scattering of 45-MeV $\alpha$ particles by the $N=82\mathrm{}$ isotones ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}$ and ${}_{}{}^{139}{}_{}{}^{}\mathrm{La}$ have been measured. Both collective- and microscopic-model distorted-wave Born-approximation analyses have been performed to ascertain the collective nature of the levels excited; the wave functions used in the microscopic-model calculations were the eigenfunctions of the pseudo $L-S$ coupling scheme recently developed by Hecht and Adler. The results of the collective-model analysis of the ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}(\alpha ,{\alpha }^{\prime })$ data indicate that none of the levels excited are well described as mass vibrations. The microscopic-model calculations indicate that significant contributions from the core are needed in order to fit the magnitudes of the cross sections for transitions to the first $2^{+}$ (1.597 MeV) and $4^{+}$ (2.084 MeV) states of ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}$. The collective-model analysis of the ${}_{}{}^{139}{}_{}{}^{}\mathrm{La}(\alpha ,{\alpha }^{\prime })$ data permits parity assignments to be made for all levels excited; unfortunately, it is not possible to understand the features of the ($\alpha ,{\alpha }^{\prime }$) spectrum in terms of a weak-coupling model. The microscopic-model calculations for the ${}_{}{}^{139}{}_{}{}^{}\mathrm{La}(\alpha ,{\alpha }^{\prime })$ experiment indicate that transitions which require a "pseudospin flip" are strongly inhibited. The features of the experimental ${}_{}{}^{139}{}_{}{}^{}\mathrm{La}(\alpha ,{\alpha }^{\prime })$ spectrum are consistent with this prediction. The $\Delta B=0\mathrm{}$ selection rule suggested by Hecht and Adler ($B$ is the total pseudospin) is approximately obeyed for both reactions.