Irradiation of enriched ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}$ with 14.8-MeV neutrons was found to produce a new radioactivity with a half-life of 1.5 ± 0.3 sec which was assigned to an isomer of ${}_{}{}^{122}{}_{}{}^{}\mathrm{In}$. The decay of the 7.5-sec ${}_{}{}^{122}{}_{}{}^{}\mathrm{In}$ isomer was also studied and a new half-life of 10.0 ± 0.5 sec determined.

Internal ionization in the $K$ shell during nuclear $\beta$ decay has been studied experimentally as well as theoretically. The subsequent $K$ x rays were measured in coincidence with emitted electrons for various segments of the $\beta$ spectra of ${}_{}{}^{147}{}_{}{}^{}\mathrm{Pm}$ and ${}_{}{}^{63}{}_{}{}^{}\mathrm{Ni}$, using $4\pi$ detection geometry for these electrons; the sources were mounted in the electron detectors. The energy-dependent ionization probability $P_K\left(E_{\beta }^0\right)$ was measured as a function of $E_{\beta }^0$, where the parameter $E_{\beta }^0$ is defined as a sum of energies of the $\beta$ particle and emitted $K$ electron plus the $K$-shell binding energy of the daughter atom. This energy-dependent and the simultaneously measured total ionization probabilities have been found to be in fairly good agreement with theoretical values calculated by the theory developed based on a relativistic one-step treatment of electron shakeoff. From this result it has been established that electron shakeoff is the predominant mechanism even for electrons ($\beta$ particles and $K$ electrons) emitted with very low energies. As to the total ionization probability, it is pointed out that the theoretical values calculated by the simple wave-function-overlap theory using self-consistent-field wave functions should be improved by multiplying by a correction factor, a function of $B_K$ and $E_0$, where $B_K$ is the $K$-shell binding energy of the daughter atom and $E_0$ is the ordinary maximum kinetic energy of $\beta$ rays. The theoretical treatment of the phenomenon and future fruitful experiments to be hoped for are also discussed.

The ${}_{}{}^{92}{}_{}{}^{}\mathrm{Mo}({}_{}{}^3{}_{}{}^{}\mathrm{He},d){}_{}{}^{93}{}_{}{}^{}\mathrm{Tc}$ reaction has been studied at 35-MeV bombarding energy. Several $T_{<}$ levels are observed below 6-MeV excitation energy, and evidence is presented for sizable $p_{\frac{3}{2}}^{}{}_{}{}^{-2\mathrm{}}$ and $f_{\frac{5}{2}}^{}{}_{}{}^{-2\mathrm{}}$ components in the ${}_{}{}^{92}{}_{}{}^{}\mathrm{Mo}$ proton configuration. Four deuteron groups, corresponding to $T_{>}=\frac{9}{2}$ analogs of low-lying levels in ${}_{}{}^{93}{}_{}{}^{}\mathrm{Mo}$ are also observed. Distorted-wave Born-approximation calculations were performed, using form factors calculated for a proton quasibound by the Coulomb and centrifugal barrier for the proton-unstable levels (≥4.08-MeV excitation energy). The data are well described by the calculations, and reasonable spectroscopic factors are obtained for both $T_{<}$ and $T_{>}$ levels.

$\gamma$-ray singles and coincidence measurements have been carried out on the decay of ${}_{}{}^{156}{}_{}{}^{}\mathrm{Tb}$ with Ge(Li) detectors to study levels of ${}_{}{}^{156}{}_{}{}^{}\mathrm{Gd}$. A total of 102 transitions were observed, of which 52 were previously unreported. Of these 78 were placed in the decay scheme with levels at: 88.967, $2^{+}$0; 288.16, $4^{+}$0; 584.74, $6^{+}$0; 1129.52, $2^{+}$0; 1154.23, $2^{+}$2; 1242.5, $1^{-}$(0); 1248.08, $3^{+}$2; 1258.4, $2^{+}$0; 1276.22, $3^{-}$(0); 1297.7, $4^{+}$0; 1319.69, $2^{-}$(1); 1355.52, $4^{+}$2; 1366.6, $1^{-}$(1); 1462.4, $4^{+}$0; 1468.5, ($4^{-}$1); 1510.67, $4^{+}$(4); 1539.0, ($3^{-}$1); 1622.64, $5^{+}$(4); 1852.09, $3^{-}$(2); 1943.41, $3^{-}$; 2045.04, $4^{-}$(4); 2103.49, $3^{-}$; 2175.6, 2181.5, and 2232.9 keV. The spin, parity, and $K$ assignments are given where known after each level. 12 of these levels are reported in this decay for the first time.

The decay of ${}_{}{}^{125}{}_{}{}^{}\mathrm{Sb}$ to levels of ${}_{}{}^{125}{}_{}{}^{}\mathrm{Te}$ has been investigated using low-temperature nuclear orientation achieved by dilution refrigeration and adiabatic demagnetization. Angular distributions of eight $\gamma$ rays were observed using Ge(Li) detectors. The values of the $\frac{E2\mathrm{}}{M1\mathrm{}}$ $\gamma$-transition multipole mixing ratios deduced were (energies in keV): $\delta \mathrm{}\left(636\right)={+0.341\mathrm{}}_{-0.006\mathrm{}}^{+0.005\mathrm{}}$; $\delta \mathrm{}\left(428\right)=-0.542\mathrm{}\pm 0.016$; $-1.7\mathrm{}\le \delta \mathrm{}\left(177\right)\mathrm{}\le -0.5\mathrm{}$. In addition, mixing amplitudes of angular momentum components in the $\beta$-radiation fields were extracted.

The dynamic model of asymmetric fission used in calculating the mass and kinetic energy distributions of the fragments from thermal-neutron-induced fission of ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}$ is employed here to calculate these distributions for fission at higher excitation energies and for other heavy nuclei at low excitation energies. The model itself is investigated with respect to the semiphenomenological shell correction. It is found that the mass distribution of the fragments in the reaction ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}\mathrm{}(n,f)\mathrm{}$, which for thermal neutrons is strongly peaked at the heavy-fragment mass 132, goes over into a symmetric mass distribution at a compound-nuclear temperature of about 6 MeV.

The nuclear structure of the $N=82\mathrm{}$ isotones ${\mathrm{Ba}}^{138}$, ${\mathrm{La}}^{139}$, ${\mathrm{Ce}}^{140}$, ${\mathrm{Pr}}^{141}$, and ${\mathrm{Nd}}^{142}$ has been studied using the single-proton-transfer reactions (${\mathrm{He}}^3,d$) and ($d,{\mathrm{He}}^3$) on ${\mathrm{La}}^{139}$, ${\mathrm{Ce}}^{140}$, and ${\mathrm{Pr}}^{141}$ targets. Distorted-wave analysis of the angular distributions has been used to determine angular momentum transfers and spectroscopic factors for states up to about 3-MeV excitation. The experimental data are compared with recent shell-model calculations, and in particular with the results of calculations using a new simplifying coupling scheme, the pseudo spin-orbit coupling scheme.

A direct measurement of the $\frac{P_M}{P_L}$ electron-capture ratio has been made by means of internal-source scintillation-counter techniques. The ${\mathrm{Cs}}_2$Pt${\mathrm{}\left(\mathrm{CN}\right)\mathrm{}}_4$${\mathrm{H}}_2$O scintillator crystal was synthesized from a Pt compound containing ${}_{}{}^{193}{}_{}{}^{}\mathrm{Pt}$ activity, so that the activity occupied lattice positions in the scintillator. The $\frac{P_M}{P_L}$ capture ratio was found to be 0.386 ± 0.014. From this, the exchange correction for the $\frac{P_M}{P_L}$ capture ratio of Pt could be evaluated to be 1.11 ± 0.04, and from the specific activity of the sample it was possible to re-determine the partial half-life for $L$ capture; the result 73 ± 9 yr corresponds to a $log\mathrm{ft}$ of 7.2±0.1 and a total half-life of 50±9 yr.

The $L$-electron-capture half-life of ${}_{}{}^{193}{}_{}{}^{}\mathrm{Pt}$ has been remeasured and found to be 94 ± 30 yr. The corresponding $log\mathrm{ft}$ is calculated to be 7.3 ± 0.1.

The neutron spectra produced by the ${}_{}{}^{89}{}_{}{}^{}Y\mathrm{}(p,n)\mathrm{}{}_{}{}^{89}{}_{}{}^{}\mathrm{Zr}$, ${}_{}{}^{93}{}_{}{}^{}\mathrm{Nb}\mathrm{}(p,n)\mathrm{}{}_{}{}^{93}{}_{}{}^{}\mathrm{Mo}$, and ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}\mathrm{}(p,n)\mathrm{}{}_{}{}^{181}{}_{}{}^{}\mathrm{W}$ reactions have been measured at five angles between 15 and 135° for proton energies between 7.8 and 14.8 MeV. It is concluded that the data at low bombarding energies are consistent with a compound-nuclear-reaction mechanism. A constant-temperature level density for energies below the neutron binding energy is found to be appropriate for the residual nuclei ${}_{}{}^{89}{}_{}{}^{}\mathrm{Zr}$, ${}_{}{}^{93}{}_{}{}^{}\mathrm{Mo}$, and ${}_{}{}^{181}{}_{}{}^{}\mathrm{W}$, with nuclear temperatures $\theta =0.70, 0.68, \mathrm{and} 0.54$ MeV, respectively.

For bombarding energies above 10 MeV contributions from noncompound processes appear and at 14.8 MeV these are comparable in magnitude to those produced by compound-nuclear ($p,n$) reactions. On the basis of the angular distributions and the bombarding-energy dependence the relative fraction of the noncompound cross section due to direct and to pre-equilibrium reaction mechanisms is estimated.

The extracted average doorway-state width varies from 350 keV near $A=90\mathrm{}$ to about 1 MeV for $A\sim 180$.

The technique of optical pumping has been used to determine the nuclear magnetic dipole moment of spin-$\frac{3}{2}$, $4-\mathrm{h}{}_{}{}^{193}{}_{}{}^{}\mathrm{Hg}$, and the spin-$\frac{13}{2}$ isomers, $10-\mathrm{h}{}_{}{}^{193m}{}_{}{}^{}\mathrm{Hg}$, $40-\mathrm{h}{}_{}{}^{195m}{}_{}{}^{}\mathrm{Hg}$, and $24-\mathrm{h}{}_{}{}^{197m}{}_{}{}^{}\mathrm{Hg}$. Nuclear magnetic resonance was observed following orientation of the $6s^2{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$ ground state. The results are $\left|{}_{}{}^{193}{}_{}{}^{}\mu \mathrm{}\right|=0.61763\left(18\mathrm{}\right)\mathrm{}{\mu }_N$, $\left|{}_{}{}^{193m}{}_{}{}^{}\mu \mathrm{}\right|=1.0416\left(3\mathrm{}\right)\mathrm{}{\mu }_N$, $\left|{}_{}{}^{195m}{}_{}{}^{}\mu \mathrm{}\right|=1.0280\left(2\mathrm{}\right)\mathrm{}{\mu }_N$, and $\left|{}_{}{}^{197m}{}_{}{}^{}\mu \mathrm{}\right|=1.0112\left(3\mathrm{}\right)\mathrm{}{\mu }_N$, all without diamagnetic correction. Differential hfs anomalies, $\Delta$, have been calculated with respect to stable ${}_{}{}^{199}{}_{}{}^{}\mathrm{Hg}$ with the use of the previously determined values of the magnetic dipole hfs interaction constants for the $6s6p{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ level. We obtain ${}_{}{}^{193}{}_{}{}^{}\Delta _{}^{199}{}_{}{}^{}=0.0054\mathrm{}\left(27\right)\mathrm{}$, ${}_{}{}^{193m}{}_{}{}^{}\Delta _{}^{199}{}_{}{}^{}=0.0108\mathrm{}\left(3\right)\mathrm{}$, ${}_{}{}^{195m}{}_{}{}^{}\Delta _{}^{199}{}_{}{}^{}=0.0106\mathrm{}\left(2\right)\mathrm{}$, and ${}_{}{}^{197m}{}_{}{}^{}\Delta _{}^{199}{}_{}{}^{}=0.0105\mathrm{}\left(6\right)\mathrm{}$.

Six isotopes of element 103, with mass numbers 255 through 260, have been studied by means of $\alpha$-particle spectroscopy. The half-lives of the nuclides, and the energies and the intensities of their main $\alpha$-particle groups were observed to be:

A large number of target-projectile combinations were used in synthesizing the lawrencium isotopes. Representative excitation curves for producing the nuclides are displayed. Upper limits for decay by electron capture have been determined. $\alpha$-decay hindrance factors have been calculated using the spin-independent equations of Preston. The $\alpha$-decay energy systematics of the heaviest elements is discussed.

The half-life of ${}_{}{}^{162}{}_{}{}^{}\mathrm{Tm}$ was determined to be 21.77 ± 0.26 min. Eight $\gamma$ rays in addition to the Er $K$ x rays and the annihilation radiation were observed in the decay of ${}_{}{}^{162}{}_{}{}^{}\mathrm{Tm}$. Based on the energies and intensities of these $\gamma$ rays and the level schemes of the even-mass erbium isotopes, a tentative decay scheme of ${}_{}{}^{162}{}_{}{}^{}\mathrm{Tm}$ is proposed. The $K$-capture-to-positron ratio in the decay of ${}_{}{}^{162}{}_{}{}^{}\mathrm{Tm}$ was found to be 12. The maximum positron energy estimated from this ratio and from other results in this work is in gross disagreement with the calculated decay energy of ${}_{}{}^{162}{}_{}{}^{}\mathrm{Tm}$.

$\gamma$ radiation following the decay of ${}_{}{}^{143}{}_{}{}^{}\mathrm{Ce}$ to levels in ${}_{}{}^{143}{}_{}{}^{}\mathrm{Pr}$ has been studied with curved-crystal and Ge(Li) spectrometers. Coincidence spectra were taken with a Ge(Li)-Ge(Li) combination and with a Ge(Li)-NaI(Tl) combination. 28 transitions were observed, including a transition at 891 keV which was previously unreported. The 891-keV transition has been placed in the decay scheme on the basis of coincidence data. The 557-keV $\gamma$ ray known to be associated with the decay of ${}_{}{}^{143}{}_{}{}^{}\mathrm{Ce}$ has been observed in coincidence spectra for the first time.

The partial-wave calculation of the quadrupole effect of polarized target nuclei on the elastic scattering of charged particles at low incident energies is carried out. It is shown that the second-order quadrupole effect can easily dominate the first-order effect. The case in which muons are projectiles is exceptional.

Systematics of the effective neutron-proton interactions in mirror nuclei are discussed. Magic- and submagic-number effects are clearly indicated. Behavior of the charge-exchange part of the effective neutron-proton interaction is shown.

The nature of the ${\mathrm{½}}^{+}$ ground states of the light isotopes of cesium is discussed in the framework of the unified model. These states are well reproduced by the Nilsson model for oblate shapes, as well as by the intermediate-coupling version of the unified model.

The non-normal-parity states for the five-nucleon system are obtained in the shell-model with particle-hole interactions. The residual force used is the separable smooth potential due to Tabakin. Coupling of the shell-model wave functions to deuteron and single-particle channels is calculated semiquantitatively, and the results are used in an $R$-matrix calculation of the cross section for photocapture of deuterons by tritons. A broad peak in the cross section at about 21-MeV excited energy due to capture through a ${\frac{5}{2}}^{+}$ state is predicted.

A new experimental setup for measuring particle-particle angular correlations with a position sensitive detector is presented. The method was investigated using the reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}({}_{}{}^{12}{}_{}{}^{}\mathrm{C},{\alpha }_1){}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}\left({\alpha }_2\right){}_{}{}^{16}{}_{}{}^{}\mathrm{O}$. The first $\alpha$ particle was detected in a telescope located at 0°, whereas the second one was measured in a 55-mm-long position-sensitive detector covering angles between 30 and 110°. From the measured correlation functions the spins of the intermediate ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ states can be determined uniquely. A new $J^{\pi }=7^{-}$ state was found at an excitation energy of 16.5 ± 0.3 MeV.

The effective interactions between inequivalent nucleons in the $1p$ and $2s$, $1d$ shells are investigated from an exact shell-model calculation via a least-squares fit of the experimental energy spectra of the non-normal-parity states in oxygen isotopes.