Proton inelastic scattering from ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}$, and ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$ has been measured at 40 MeV. Angular distributions have been obtained from 10 to 80° for states up to 8 MeV of excitation in ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$ and ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$, and to 4.5 MeV in ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}$. The cross sections for exciting the low-lying states that have relatively simple wave functions were analyzed in terms of a microscopic model, using realistic nucleon-nucleon forces. Core polarization is shown to be important, and it is seen that a strength obtained from the bound-state matrix elements of Kuo and Brown is adequate to describe the observed scattering. A macroscopic collective-model analysis of the data is also presented.

The low-lying states of the calcium isotopes ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ca}$ through ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ca}$ are discussed within the framework of the conventional shell model. An inert ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ core is assumed. Calculations are made in several basis-vector spaces involving active $0f_{\frac{7}{2}}$, $1p_{\frac{3}{2}}$, $0f_{\frac{5}{2}}$, $1p_{\frac{1}{2}}$, and $0g_{\frac{9}{2}}$ neutron orbits. In one set of calculations, we use a "realistic" effective interaction derived for this mass region by Kuo and Brown. The shell-model results suggest that, in this effective interaction, the interactions of $f_{\frac{7}{2}}$ neutrons with $p_{\frac{3}{2}}$, $p_{\frac{1}{2}}$, and $f_{\frac{5}{2}}$ neutrons are too strong. In other calculations, with a modified Kuo-Brown interaction, we find the calculated spectra for the low-lying states of the calcium isotopes are in agreement with observed spectra, with several significant exceptions. The exceptions are that the second $0^{+}$ and $2^{+}$ states observed in ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{44}{}_{}{}^{}\mathrm{Ca}$, and ${}_{}{}^{46}{}_{}{}^{}\mathrm{Ca}$ are not accounted for in the calculation. Calculated spectroscopic factors for $f_{\frac{7}{2}}$ transfers are in good agreement with experimental spectroscopic factors, and the observed centroids of the $p_{\frac{3}{2}}$ single-particle strengths are reasonably well reproduced. Our results also indicate that "core-excitation" effects are significant above about 2.5 MeV in ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ca}$ through ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$.

The ground-state threshold for the reaction ${}_{}{}^{39}{}_{}{}^{}\mathrm{K}\mathrm{}(p,n)\mathrm{}{}_{}{}^{39}{}_{}{}^{}\mathrm{Ca}$ has been measured to be 7.492 ±0.006 MeV. The absolute value of the total reaction cross section has been determined from threshold to 10.5-MeV bombarding energy. From the threshold energy, the mass excess of ${}_{}{}^{39}{}_{}{}^{}\mathrm{Ca}$ is calculated to be -27 281 ± 6 keV, which agrees within the error limits with positron end-point results but not with an earlier measurement of this threshold.

Angular correlations of $\gamma$ rays have been measured in coincidence with protons leading to states in ${}_{}{}^{42}{}_{}{}^{}\mathrm{Sc}$ at 0.61, 1.49, 1.51, 1.59 MeV, and one member of a doublet at 1.88 MeV. The measurements imply spin 1 for the 0.61-MeV state and for one member of the 1.88-MeV doublet. The best fit to the correlation for the 1.49-MeV state is obtained for spin 3, but other spins cannot be excluded. The 1.51-MeV state decays 100% to the isomeric $7^{+}$ state at 0.62 MeV. The 1.59-MeV state is measured to have spin 2. The relative populations of the $M=\pm 1$ and $M=0\mathrm{}$ magnetic substates are extracted from the data and compared with a simple direct-reaction model.

We have measured the hfs separation and nuclear magnetic moment of 6.2-day ${}_{}{}^{196}{}_{}{}^{}\mathrm{Au}$. The results we obtain are: $\Delta \nu \left({}_{}{}^{196}{}_{}{}^{}\mathrm{Au}\right)=21\mathrm{}347.2522\left(15\right)\mathrm{}$ MHz and ${\mu }_I({}_{}{}^{196}{}_{}{}^{}\mathrm{Au};\mathrm{uncorr})=+0.5823\mathrm{}\left(14\right)\mathrm{}{\mu }_N$. These values give the hfs anomaly with respect to ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$, ${}_{}{}^{196}{}_{}{}^{}\Delta _{}^{197}{}_{}{}^{}=-8.02\mathrm{}\left(24\right)\%$. These measurements reconfirm the existence of large hfs anomalies in the gold isotopes. They also show that the ground-state nuclear structure of ${}_{}{}^{196}{}_{}{}^{}\mathrm{Au}$ is similar to that of ${}_{}{}^{198}{}_{}{}^{}\mathrm{Au}$.

The atomic-beam magnetic-resonance method has been used to measure the nuclear spin $I$ and the hyperfine structure constants $a$ and $b$ in the ${}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ atomic state of 38-h ${}_{}{}^{69}{}_{}{}^{}\mathrm{Ge}$ and 82-min ${}_{}{}^{75}{}_{}{}^{}\mathrm{Ge}$, and in the ${}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$ atomic state of ${}_{}{}^{75}{}_{}{}^{}\mathrm{Ge}$ and 11-day ${}_{}{}^{71}{}_{}{}^{}\mathrm{Ge}$. From these measurements, the nuclear moments ${\mu }_I$ and $Q$ are deduced. The results are: for ${}_{}{}^{69}{}_{}{}^{}\mathrm{Ge}$, $I=\frac{5}{2}$, $a\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)=\mp 23.40\left(3\right)\mathrm{}$ MHz, $b\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)=\pm 8.28\left(8\right)\mathrm{}$ MHz, ${\mu }_I\left(\mathrm{uncorr}\right)=\pm 0.733\left(7\right)\mathrm{}{\mu }_N$, and $Q\left(\mathrm{uncorr}\right)=\pm 0.028\left(6\right)\mathrm{}$ b; for ${}_{}{}^{71}{}_{}{}^{}\mathrm{Ge}$, $a\left({}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}\right)=+360.53\mathrm{}\left(4\right)\mathrm{}$ MHz; and for ${}_{}{}^{75}{}_{}{}^{}\mathrm{Ge}$, $I=\frac{1}{2}$, $a\left({}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\right)=-81.06\mathrm{}\left(8\right)\mathrm{}$ MHz, $a\left({}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}\right)=+335.94\mathrm{}\left(9\right)\mathrm{}$ MHz, and ${\mu }_I\left(\mathrm{uncorr}\right)=+0.508\mathrm{}\left(5\right)\mathrm{}{\mu }_N$.

The level structure of ${}_{45}{}^{}{}_{}{}^{}\mathrm{Rh}_{}^{105}{}_{}{}^{}$, below 2 MeV in excitation, was studied by ${\mathrm{Ru}}^{104}({\mathrm{He}}^3,d){\mathrm{Rh}}^{105}$ at $E_{{\mathrm{He}}^3}=18\mathrm{}$ MeV, and by ${\mathrm{Pd}}^{108}(p,\alpha ){\mathrm{Rh}}^{105}$ at $E_p=15\mathrm{}$ MeV. An Enge split-pole spectrograph was used for high-resolution analysis of the reaction products. Particle detection for deuterons was achieved with nuclear emulsions, while position-sensitive "triode" counters were used for the $\alpha$ particles. Targets were kept thin enough to permit total experimental resolutions of 12-13 keV. Comparison of 17 measured (${\mathrm{He}}^3,d$) angular distributions with nonlocal, finite-range distorted-wave Born-approximation (DWBA) calculations indicated a predominance of $l=2\mathrm{}$ transfers, and yielded $J^{\pi }$ limits for the more strongly excited states. Differential ${\mathrm{Pd}}^{108}(p,\alpha ){\mathrm{Rh}}^{105}$ cross sections were obtained over the angular range of from 8 to 100° and complement the (${\mathrm{He}}^3,d$) measurements, frequently exciting levels not seen in proton stripping. DWBA triton-cluster transfer calculations reproduce the empirically observed $l=1\mathrm{} j$ dependence. A weaker, but detectable, $j$ dependence is predicted for $l=3\mathrm{}$. The observed ${\mathrm{Rh}}^{105}$ energy-level scheme is compared with weak-coupling-model expectations and the results of earlier $\beta$-decay studies.

$\alpha$-cluster knockout from ${\mathrm{Be}}^9$, ${\mathrm{C}}^{12}$, and ${\mathrm{O}}^{16}$ by 160-MeV protons was investigated. The outgoing proton and $\alpha$ particle were detected in coincidence and their momenta measured with good resolution. Knockout, sequential decay, and spallation reactions were observed. Proton and $\alpha$ detection angles were varied so as to test the plane-wave impulse-approximation (PWIA) model of the knockout reaction over a wide range of the effective $p$-cluster interaction. The method, apparatus, and carbon results are discussed in this paper. Measured values of the fully differential cross section ($\frac{d\sigma }{d{\Omega }_{\alpha }d{\Omega }_{p}d{T}_p}$) are given, and are shown to vary nearly as predicted by the PWIA. The errors due to finite detector sizes (finite momentum resolution) are discussed in some detail. The recoil correction to the usual PWIA expression for the cross section is derived. The branching ratio to the first excited state of the residual ${\mathrm{Be}}^8$ nucleus, as well as the effective number of $\alpha$ clusters in ${\mathrm{C}}^{12}$, are discussed and compared with theoretical predictions.

Elastic and inelastic nuclear resonant scattering of monochromatic photons from ${}_{}{}^{203}{}_{}{}^{}\mathrm{Tl}$ has been studied using a 20-cc Ge(Li) detector. The $\gamma$ source was obtained from thermal-neutron capture in titanium. The scattering isotope was identified by using an isotopically enriched thallium target. The energy of the resonance level in ${}_{}{}^{203}{}_{}{}^{}\mathrm{Tl}$ was found to be 6.418 MeV. Assuming the high-energy lines to be primary transitions deexciting the resonance level, some 14 energy levels were found from the ground state up to 2.9 MeV, 4 of which may be identified with recently reported levels.

By measuring the angular distribution of the scattered radiation, the spin of the 6.418-MeV level was determined to be ½, and thus, based on the assumption of dipole transitions, the spins of several low-lying levels were found to be either ½ or $\frac{3}{2}$. The total radiative width of the resonance level was determined and found to be ${\Gamma }_{\gamma }=0.32\mathrm{}\pm 0.06$ eV and $\frac{{\Gamma }_0}{{\Gamma }_{\gamma }}=0.026\mathrm{}$. The spectral shape of scattered radiation was found to have a strong intensity bump at about 5 MeV; this is discussed in the light of similar bumps obtained in ($n,\gamma$) and ($d,p\gamma$) reactions on nuclei in the same mass region.

The energy distribution of the neutrons emitted in the fission of ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$ and ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ induced by 155-MeV protons was measured at 0 and 90° with respect to the fission fragment direction. The neutron velocity was measured by the time-of-flight method in coincidence with the measurement of the kinetic energy of the two fission fragments. The number of postfission neutrons as a function of the fragment mass and the energy distribution of the postfission neutrons were determined without reference to any theoretical model. The number of prefission neutrons was determined on the assumption of isotropic emission from the excited nucleus. With this assumption we find that 5.8±1.0 prefission neutrons are emitted from U and 6.9±1.0 from Bi. The number of postfission neutrons is 5.1±0.5 for U and 4.2±0.5 for Bi. We compare our experimental results with the results of calculations based on the usual model of a prompt intranuclear cascade followed by neutron evaporation-fission competition with several assumptions for $\frac{{\Gamma }_f}{{\Gamma }_n}$ (ratio of fission width to neutron emission width). We are unable to find a consistent set of parameters which would give good agreement between the calculated results, our experimental results, radiochemical results for spallation residues, and total fission cross-section measurements. Our experimental results indicate that $\frac{{\Gamma }_f}{{\Gamma }_n}$ decreases at high excitation energies. We find that the number of postfission neutrons increases rapidly with increasing fragment mass for both Bi and U. When our results for U are compared with low-energy fission data for this element, it is found that almost all the additional excitation energy available in high-energy fission is concentrated in the heavy fragment.

Simultaneous Mössbauer-effect spectra of the first excited states of ${\mathrm{W}}^{182}$, ${\mathrm{W}}^{184}$, and ${\mathrm{W}}^{186}$ were observed following Coulomb excitation by 6.0-MeV $\alpha$ particles. Tungsten nuclei were in tungsten metal targets at liquid-nitrogen temperature. An absorption spectrum of the first excited state of ${\mathrm{W}}^{183}$ was also observed. Taking the half-life of the first excited state of ${\mathrm{W}}^{182}$ to be 1.377±0.014 nsec, the half-lives of the first excited states of ${\mathrm{W}}^{184}$, ${\mathrm{W}}^{186}$, and ${\mathrm{W}}^{183}$ were determined to be 1.28±0.13, 1.38±0.12, and 0.174±0.006 nsec, respectively. Data were consistent with electric quadrupole interactions in the targets. The Debye temperature of tungsten metal at liquid-nitrogen temperature was determined to be 329±8°K.

The ($d,t$) and ($d,p$) reactions induced by 20.65-MeV deuterons have been used to study the levels of ${}_{}{}^{87}{}_{}{}^{}\mathrm{Sr}$ and ${}_{}{}^{85}{}_{}{}^{}\mathrm{Sr}$ up to an excitation of 3 MeV. The mass defect of ${}_{}{}^{83}{}_{}{}^{}\mathrm{Sr}$ has been determined by the ($d,t$) reaction, and its level structure below 3 MeV has been investigated. The cross sections have been analyzed with the distorted-wave Born approximation (DWBA) to determine the $l$ values of the neutron transfers and the spectroscopic factors. Tentative spin assignments have been made on the basis of sum rules and the $j$ dependence of the cross sections.

The half-life of ${}_{}{}^{169}{}_{}{}^{}\mathrm{Hf}$ was found to be 3.26 ± 0.05 min. Several $\gamma$ rays of ${}_{}{}^{169}{}_{}{}^{}\mathrm{Hf}$ were determined, and a partial decay scheme of ${}_{}{}^{169}{}_{}{}^{}\mathrm{Hf}$ proposed. The previously reported 1.5 h ${}_{}{}^{169}{}_{}{}^{}\mathrm{Hf}$ was found to be in error. The half-lives of ${}_{}{}^{168}{}_{}{}^{}\mathrm{Hf}$, ${}_{}{}^{170}{}_{}{}^{}\mathrm{Hf}$, and ${}_{}{}^{171}{}_{}{}^{}\mathrm{Hf}$ were redetermined to be 25.95 ± 0.20 min, 15.92 ± 0.15 h, and 12.09 ± 0.35 h, respectively. Several new $\gamma$ rays of ${}_{}{}^{168}{}_{}{}^{}\mathrm{Hf}$ were observed. $\gamma$ spectra of ${}_{}{}^{170}{}_{}{}^{}\mathrm{Hf}$ and ${}_{}{}^{171}{}_{}{}^{}\mathrm{Hf}$ were redetermined, and comparisons were made with previous investigations.

In spite of ingenious investigations of the isomeric decay of 253-day ${\mathrm{Ag}}^{110m}$ by several groups of authors, the missing low-energy first excited (2-) state in ${\mathrm{Ag}}^{110}$ has so far escaped detection. High-precision studies of the $\gamma$ rays from the ${\mathrm{Ag}}^{109}(n,\gamma ){\mathrm{Ag}}^{110}$ reaction, as well as coincidence studies, now provide conclusive evidence for this level at an energy of 1.28 ± 0.10 keV.

Recently a high-resolution proton recoil spectrometer was used to measure the neutron spectrum from 20-MeV proton bombardment of ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$. Evidence for levels in ${}_{}{}^9{}_{}{}^{}\mathrm{B}$ at 1.4- and 3.2-MeV excitation was presented. Using time-of-flight techniques, we have remeasured the neutron spectrum and find no evidence for these levels.

The second-order ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ mechanism proposed by Noble can account for the recent observation of fine structure if the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}_{}^{*}{}_{}{}^{}$ and ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$ nuclei are coupled to states of definite $J^{\pi }$.

An exact shell-model framework, used in an earlier paper to interpret the odd-parity ($T=\frac{1}{2}$) states of ${\mathrm{O}}^{17}$ below 8-MeV excitation, is extended to the even-parity ($T=\frac{1}{2}$) states in this range. Good agreement between experimental and theoretical energies is achieved. A negative result is that the lowest ${\frac{3}{2}}^{+}$ state is calculated to have essentially zero single-particle strength.

The pair-distribution coefficients of the ground state of even nickel and tin isotopes are determined using both the standard BCS state and its number-projected component. The comparison of the results shows that a consistent number-conserving determination of the coefficients is, in general, necessary in the framework of the so-called projected quasiparticle Tamm-Dancoff approximations.

A comprehensive investigation of the ${\mathrm{Li}}^6$ + ${\mathrm{C}}^{12}$ reaction has been carried out for particle groups corresponding to the following states of the residual nuclei involved: 0.0, 0.871, 3.058, 3.846, and 4.551 MeV for $0^{17}$; 0.0, 6.05+6.13 (unresolved), 6.92+7.12, and 8.88 MeV for $0^{16}$; 0.0 MeV for $0^{15}$; and 0.0, 3.945, and 4.91 + 5.10 MeV for ${\mathrm{N}}^{14}$. Yield curves were measured for protons, deuterons, and $\alpha$ particles at laboratory angles of 0° and 40°, at ${\mathrm{Li}}^6$ bombarding energies from 5.6 to 14.0 MeV. Angular distributions were measured at 9.0, 10.0, 11.2, 12.0, 13.0, and 14.0 MeV for all of the above groups and from 5.6 to 6.6 MeV at 0.200-MeV intervals for most of the groups.

A comparison has been made of the accumulated $\alpha$-particle data and two-mode plane-wave and single-mode distorted-wave direct-reaction models. The proton, deuteron, and $\alpha$-particle data were also compared with the statistical compound-nucleus model.

Phillips found a linear relation between the triton energy $E_t$ and the doublet $n-d$ scattering length ${}_{}{}^2{}_{}{}^{}a$ for a variety of separable tensor potentials. We have treated many more separable potentials, and also the Tabakin and Mongan rank-two separable potentials. The linear relation holds well for two-body potentials that fit the energies of the two-body triplet bound and singlet antibound states.