The neutron inelastic scattering excitation function of the 3120-keV level in ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$ has been determined from $\gamma$-ray production cross-section measurements. The best agreement between experiment and theory was obtained with a $0^{+}$ spin and parity assignment for this level.

Angular distributions at 40 MeV and backward-angle excitation functions in the energy range 25-45 MeV have been measured for ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ elastic scattering on ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$. The ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ + ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ excitation function measured in this experiment shows no indication of the marked structure observed in earlier experiments and predicted by angular-momentum-dependent optical-model calculations. The experimental data are discussed by means of both the standard and the $L$-dependent optical models.

Excitation functions for the ${}_{}{}^{96}{}_{}{}^{}\mathrm{Mo}\mathrm{}(p,xn)\mathrm{}{}_{}{}^{97-x}{}_{}{}^{}\mathrm{Tc}$ reactions have been measured for proton bombarding energies from 10-80 MeV. These experimental results have been compared to excitation functions calculated using the most recent version of intranuclear cascade model, that known as VPOT, as well as the older STEP. The two models are compared, particularly with reference to improvements in the newer, more sophisticated VPOT. This model provides substantially better agreement with experiment than STEP, although it is also found to introduce new problems.

The $\gamma$-ray decay of the levels of ${}_{}{}^{20}{}_{}{}^{}\mathrm{F}$ at 1824, 1843, and 3176 keV has been studied. Results indicate that each of these levels has only one mode of decay. For the 1824-keV level this finding is consistent with the $L=4\mathrm{}$ transfer reported by Fortune and Crozier. Together with previous angular-correlation results this determines the probable assignments $J^{\pi }=5^{+}$ for the 1824-keV level and $J=4\mathrm{}$ for the 823-keV level. This and other recent experimental developments are in good agreement with published calculated ${}_{}{}^{20}{}_{}{}^{}\mathrm{F}$ structure by Halbert, McGrory, Wildenthal, and Pandya.

${}_{}{}^{35}{}_{}{}^{}\mathrm{P}$ has been produced via the ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}+{}_{}{}^{19}{}_{}{}^{}\mathrm{F}\to {}_{}{}^{35}{}_{}{}^{}\mathrm{P}+2p$ reaction using 42-46-MeV ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$ ions, and by the ${}_{}{}^{36}{}_{}{}^{}\mathrm{S}(t,\alpha ){}_{}{}^{35}{}_{}{}^{}\mathrm{P}$ reaction using 3.4-MeV tritons. Identification is made from the observed $\beta$-delayed $\gamma$ ray of 1572.41 ± 0.25 keV. By means of the ${}_{}{}^{34}{}_{}{}^{}\mathrm{S}(d,p\gamma ){}_{}{}^{35}{}_{}{}^{}\mathrm{S}$ reaction, the $\gamma$ ray from the first excited state of ${}_{}{}^{35}{}_{}{}^{}\mathrm{S}$ has been measured as 1572.24 ± 0.15 keV, in disagreement with previous measurements. The average of the half-lives for ${}_{}{}^{35}{}_{}{}^{}\mathrm{P}$ as measured by the first two reactions is 48.1 ± 1.4 sec. Upper limits were obtained for $\beta$-ray transitions to other excited states in ${}_{}{}^{35}{}_{}{}^{}\mathrm{S}$. No information was obtained on a possible $\beta$ transition to the ${}_{}{}^{35}{}_{}{}^{}\mathrm{S}$ ground state. The $\beta$-ray spectrum measured in coincidence with the 1572-keV $\gamma$ ray has an end point of 2337 ± 75 keV, establishing a mass excess of -24 936 ± 75 keV for ${}_{}{}^{35}{}_{}{}^{}\mathrm{P}$. These results are consistent with the expected mass and spin-parity (${\frac{1}{2}}^{+}$) of the ${}_{}{}^{35}{}_{}{}^{}\mathrm{P}$ ground state. Comparison of these results with shell-model calculations is presented.

The mass of ${}_{}{}^{33}{}_{}{}^{}\mathrm{Si}$ has been determined by forming this 6.3-sec activity in the ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}({}_{}{}^{18}{}_{}{}^{}\mathrm{O},2p+n){}_{}{}^{33}{}_{}{}^{}\mathrm{Si}$ reaction with 50-MeV ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ ions and by measuring the spectrum of $\beta$ rays in coincidence with 1848-keV $\gamma$ rays. An end-point energy of ${3980}_{-200\mathrm{}}^{+250\mathrm{}}$ keV is found for the coincident $\beta$ rays which establishes the mass excess of ${}_{}{}^{33}{}_{}{}^{}\mathrm{Si}$ as ${-20509\mathrm{}}_{-200\mathrm{}}^{+250\mathrm{}}$ keV. This result differs from the previously estimated mass by ${560}_{-200\mathrm{}}^{+250\mathrm{}}$ keV. $\mathrm{Log}\mathrm{ft}$ values for the decay of ${}_{}{}^{33}{}_{}{}^{}\mathrm{Si}$ are presented and compared with shell-model calculations. Several heavy-ion compound reactions which might be used to produce other neutron-rich nuclei in the $s-d$ shell are listed.

Evidence for the presence of twelve $3^{-}$ states in ${}_{}{}^{50}{}_{}{}^{}\mathrm{Cr}$ is presented from the angular distributions observed for the inelastic scattering of protons, deuterons, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$, and ${}_{}{}^4{}_{}{}^{}\mathrm{He}$. The nuclear transition rates are found not to depend upon the spin or isospin of the projectile, but rather upon whether or not it is strongly absorbed by the target nucleus.

In 90° scattering of 14.4-keV $\gamma$ rays from ${\mathrm{Fe}}^{57}$, we have observed several percent difference in the intensities of the conjugate lines in the six-line hyperfine spectrum depending on the vectorial relations between the wave vectors for the incident $\gamma$ ray ${\overrightarrow{\mathrm{k}}}_i$, the outgoing wave vectors ${\overrightarrow{\mathrm{k}}}_f$, and the magnetic induction field $\overrightarrow{\mathrm{B}}$. The intensity of the line corresponding to the $m=\frac{1}{2}\to \frac{3}{2}\to \frac{1}{2}$ transition differs from that of the conjugate transition $m=-\frac{1}{2}\to -\frac{3}{2}\to -\frac{1}{2}$, by +6.8 ± 2.4%. Intensity differences are also found between the $m=\frac{1}{2}\to -\frac{1}{2}\to (\frac{1}{2},-\frac{1}{2})$ line and its conjugate transition (-6.0 ± 3.5%). The sign of these asymmetries depends on whether ${\overrightarrow{\mathrm{k}}}_i\times {\overrightarrow{\mathrm{k}}}_f$ is parallel or antiparallel to the internal magnetic field $\overrightarrow{\mathrm{B}}$. It is likely that these asymmetries result from interference between electronic (Rayleigh) scattering and nuclear resonant scattering. The signs and the calculated values for the asymmetries based on theory agree with the observed values.

The $\beta$ decay of ${}_{}{}^{35}{}_{}{}^{}\mathrm{P}$ to levels of ${}_{}{}^{35}{}_{}{}^{}\mathrm{S}$ has been studied with a large-volume Ge(Li) detector and a gas-flow proportional counter. The ${}_{}{}^{35}{}_{}{}^{}\mathrm{P}$ was produced via the ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}(t,\alpha p){}_{}{}^{35}{}_{}{}^{}\mathrm{P}$ reaction by bombardment of NaCl and LiCl targets with 16-MeV tritons, and was chemically separated by conversion to phosphate ion and adsorption on a selective polyvalent anion exchanger. The half-life was measured to be 47.4 ± 0.8 sec. Only one $\gamma$ transition was observed, at 1572.2 ± 0.4 keV. The ${}_{}{}^{35}{}_{}{}^{}\mathrm{P}$ decays ${99}_{-7\mathrm{}}^{+10\mathrm{}}$% ($logft=4.1\mathrm{}\pm 0.1$) to the 1572-keV ${\frac{1}{2}}^{+}$ first excited level of ${}_{}{}^{35}{}_{}{}^{}\mathrm{S}$ and <9% ($log\mathrm{ft}>\mathrm{}6.1\mathrm{}$) to the ${\frac{3}{2}}^{+}$ ground state, whence its spin-parity is deduced to be ${\frac{1}{2}}^{+}$. Less than 0.45% of the $\beta$ transitions proceed to any of the other known ${}_{}{}^{35}{}_{}{}^{}\mathrm{S}$ levels. The results are compared with the predictions of a recent shell-model treatment.

Five levels in ${}_{}{}^{23}{}_{}{}^{}\mathrm{Na}$ were studied using nuclear resonance fluorescence. A previously reported level at 3.91 MeV was identified as a doublet with levels at 3914.0 ± 1.8 and 3916.3 ± 1.8 keV. Levels of 5375.8 ± 2.7, 5742.7 ± 2.9, and 5768.3 ± 2.9 keV have widths ($g\Gamma$) of ${2.45}_{-0.41\mathrm{}}^{+0.48\mathrm{}}$, ${1.29}_{-0.09\mathrm{}}^{+0.10\mathrm{}}$, and ${0.62}_{-0.04\mathrm{}}^{+0.05\mathrm{}}$ eV, respectively, as measured by self-absorption experiments. The $\gamma$-ray branching ratios for these levels were measured with a 40-${\mathrm{cm}}^3$ Ge(Li) spectrometer.

The ${\mathrm{Ca}}^{44}({\mathrm{He}}^3,t){\mathrm{Sc}}^{44}$ reaction has been studied, at in incident energy of $E_{{\mathrm{He}}^{3++}}=25\mathrm{}$ MeV, with a magnetic spectrograph. A total of 52 levels in ${\mathrm{Sc}}^{44}$ have been identified below an excitation energy of 3.35 MeV. 10 of the observed levels have not been previously reported. Angular distributions have been measured for most of the levels and analyzed by means of the distorted-wave Born approximation. Definite $L$-transfer values and spin assignments have been made to many levels. As a result, eight states predicted by a recent ${\mathrm{}\left(\mathrm{fp}\right)\mathrm{}}^4$ calculation have been identified. In addition, four of the states predicted by a calculation with a single $d_{\frac{3}{2}}$ hole have been tentatively identified. The isobaric analog of the ${\mathrm{Ca}}^{44}$ ground state was located at an excitation energy of 2781 ± 5 keV, in good agreement with previous results.

Irradiation of enriched ${}_{}{}^{160}{}_{}{}^{}\mathrm{Gd}$ with fast neutrons was found to produce a new radioactivity which was assigned to the ($n,\alpha$) product ${}_{}{}^{157}{}_{}{}^{}\mathrm{Sm}$. The following radiation characteristics were observed to belong to ${}_{}{}^{157}{}_{}{}^{}\mathrm{Sm}$: half-life 83 ± 2 sec, $\gamma$-ray energy 121.5 ± 0.5 keV, and maximum ${\beta }^{-}$-ray energy 2.83 ± 0.05 MeV.

The generator-coordinate method based on projection from constrained Hartree-Fock states is applied to obtain the $T=0\mathrm{}$ energy levels of ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$. The results obtained with the strength of the external quadrupole field as a generator coordinate compare very well with those of exact shell-model calculations.

The excitation function for the positron decay following the ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}\mathrm{}(p,n)\mathrm{}{}_{}{}^{36}{}_{}{}^{}\mathrm{K}$ reaction has been measured from 15-30 MeV using chopped proton beams from the Triangle Universities Nuclear Laboratory Cyclo-Graaff accelerator. These data were also used to measure the ${}_{}{}^{36}{}_{}{}^{}\mathrm{K}$ half-life, giving a value of 341 ± 6 msec. Examination of the data at proton energies above the predicted ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}\mathrm{}(p,2n)\mathrm{}{}_{}{}^{35}{}_{}{}^{}\mathrm{K}$ reaction threshold revealed no positron activity which could be attributed to the decay of the as yet unobserved nuclide ${}_{}{}^{35}{}_{}{}^{}\mathrm{K}$. An 80-${\mathrm{cm}}^3$ Ge(Li) detector was used to study γ transitions in ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}$ arising from the decay of ${}_{}{}^{36}{}_{}{}^{}\mathrm{K}$. The relative intensities of nine $\gamma$ rays with energies of 1969.8 ± 0.5, 2171.5 ± 0.9, 2208.3 ± 0.4, 2433.7 ± 0.4, 2472.0 ± 0.8, 4180.4 ± 1.0, 4441.7 ± 0.6, 4643.7 ± 1.4, and 6612.7 ± 0.8 keV were used to deduce positron branching ratios of 46, 11, and 43% to ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}$ levels located at 1969.9 ± 0.5, 4442.0 ± 0.5, and 6613.3 ± 0.6 keV, respectively.

The recoil-distance-Doppler-shift method has been used to measure the lifetimes of the 2815- and 3598-keV levels of ${}_{}{}^{39}{}_{}{}^{}\mathrm{K}$. These excited states were populated by the reaction ${}_{}{}^6{}_{}{}^{}\mathrm{Li}({}_{}{}^{35}{}_{}{}^{}\mathrm{Cl},d){}_{}{}^{39}{}_{}{}^{}\mathrm{K}$ using 68-MeV ${}_{}{}^{35}{}_{}{}^{}\mathrm{Cl}$ ions. The energies of the $\gamma$ rays from these two levels were determined with a 55-${\mathrm{cm}}^3$ Ge(Li) detector to be 783(±1), 2815(±1), and 3598(±1) keV. The mean lifetime of the 2815-keV level was measured as 79(±8) psec, and that of the 3598-keV level as 59(±4) psec. The corresponding $E3\mathrm{}$ strengths of 6.0(±0.1) and 25.5(±1.5) Weisskopf units are in very good agreement with the phonon-hole model calculations of Goode and Zambick.

$\gamma -\gamma$ angular correlation and time-integral perturbed-angular-correlation measurements involving low-lying levels of ${}_{}{}^{28}{}_{}{}^{}\mathrm{Al}$ have been performed. The 1343-30-keV, 943-30-keV, and 400-943-keV $\gamma -\gamma$ angular correlations were studied simultaneously. The results conclusively establish the spin and parity assignments for the ground, 30-, 973-, and 1373-keV states to be $3^{+}$, $2^{+}$, $0^{+}$, and $1^{+}$, respectively. Analysis of the data indicates that the mixing amplitude for the $2^{+}$ → $3^{+}$ transition is $\delta \left(\frac{E2\mathrm{}}{M1\mathrm{}}\right)=-0.004\mathrm{}\pm 0.006$ and for the $1^{+}$ → $2^{+}$ transition $\delta \left(\frac{E2\mathrm{}}{M1\mathrm{}}\right)=+0.35\mathrm{}\pm 0.10$. The moment of the $2^{+}$ state was determined by time-integral perturbed angular correlations to be $(+4.27\mathrm{}\pm 0.40){\mu }_N$. The implications of this value for the systematics of magnetic moments in the vicinity of $A=28\mathrm{}$ are discussed particularly in relation to the theory of weak magnetism in $\beta$ decay.

The ${}_{}{}^{21}{}_{}{}^{}\mathrm{Ne}\mathrm{}(d,p)\mathrm{}{}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ reaction has been studied at 12-MeV incident energy. Angular distributions of protons have been extracted for 31 transitions leading to levels in ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ up to 9.10-MeV excitation energy. Angular momentum transfers have been identified and spectroscopic factors extracted for 27 levels by comparison with distorted-wave Born-approximation predictions. Experimental spectroscopic factors for the low-lying states have been compared with the predictions of the unified rotational model. The results of the present study indicate that the ground-state rotational band of ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ is formed by placing an additional neutron in Nilsson orbit No. 7 (${\frac{3}{2}}^{+}\mathrm{}\left[211\right]\mathrm{}$). Several states have been identified which belong to $K^{\pi }=1^{+} \mathrm{and} 4^{+}$ bands formed by stripping a neutron to Nilsson orbit No. 5 (${\frac{5}{2}}^{+}\mathrm{}\left[202\right]\mathrm{}$) and to $K^{\pi }=1^{+} \mathrm{and} 2^{+}$ bands formed by stripping to orbit No. 9 (${\frac{1}{2}}^{+}\mathrm{}\left[211\right]\mathrm{}$).

The ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}({}_{}{}^7{}_{}{}^{}\mathrm{Li},t){}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ reaction has been studied at 12-MeV incident energy. Angular distributions have been extracted for 22 triton groups leading to states in ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ up to 8.59 MeV in excitation energy. The experimental angular distributions have been compared with the predictions of the Coulomb-distorted plane-wave model. $L$ values have been assigned and relative $\alpha$-cluster widths have been extracted for the strong transitions. Significant $\alpha$ clustering has been observed for 10 states in ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ between 6.24- and 8.59-MeV excitation energy. Spin and parity assignments have been made to these states from the combined results of the ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}({}_{}{}^7{}_{}{}^{}\mathrm{Li},t){}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ and ${}_{}{}^{21}{}_{}{}^{}\mathrm{Ne}\mathrm{}(d,p)\mathrm{}{}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ reaction. The classification of the $\alpha$-cluster states into rotational bands has been discussed within the framework of the SU(3) model.

The effects of weak particle-hole admixtures on magnetic multipole properties of ${}_{}{}^{38}{}_{}{}^{}\mathrm{Cl}$ and ${}_{}{}^{40}{}_{}{}^{}\mathrm{K}$ are investigated and the results are compared with experiment, with particular emphasis on $M1\mathrm{}$ transitions between members of the lower quartet of states in each nucleus. In ${}_{}{}^{40}{}_{}{}^{}\mathrm{K}$, the admixtures tend to decrease the differences between theoretical and experimental values except for the magnetic moment. However, the same procedure leads to larger discrepancies with experiment in ${}_{}{}^{38}{}_{}{}^{}\mathrm{Cl}$. In addition, in the latter nucleus the abnormally large $M1\mathrm{}$ transition strength from the second $3^{-}$ level to the first $4^{-}$ state cannot be understood if only weak-configuration mixing is assumed. On the other hand, one can account for the experimentally observed strongly inhibited $M3\mathrm{}$ transition between the $5^{-}$ and $2^{-}$ states of ${}_{}{}^{38}{}_{}{}^{}\mathrm{Cl}$. Our prime interest is in exhibiting the effects of the separate particle-hole admixtures in order to isolate the source of the discrepancies.

Employing the central Yukawa interaction, and renormalized matrix elements for the Hamada-Johnston and Tabakin potentials, self-consistent Hartree-Fock, Hartree-Fock-Bogoliubov (HFB), and spherical BCS calculations for even calcium and nickel isotopes are carried out. The existence of spherical ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{56}{}_{}{}^{}\mathrm{Ni}$ cores is assumed and the calcium and nickel isotopes are treated within the framework of single-closed-shell structure. It is found that for a given isotope and interaction the HFB and spherical BCS approximations always correspond to the same actual minimum energy solution. This feature is observed for all the isotopes and interactions considered here, though the quasiparticle energies and the occupation numbers are found to differ. For Ca isotopes the BCS results are also compared with the shell-model calculations of McGrory, Wildenthal, and Halbert, and are found to approximate the ground-state properties of all the even isotopes rather well.