With semiconductor detectors and time-of-flight equipment, measurements, similar to those made in a previous study of uranium fission, have been made on members of fragment pairs resulting from fission of bismuth induced by 2.9-GeV protons. Fragment-pair angular correlation and fragment energies were measured in addition to velocity of one fragment; single-fragment mass spectra were thus determined. It was inferred from the mean fragment masses that the distribution of cascade deposition energies associated with bismuth fission is narrower than it is for uranium fission; neither low deposition energies nor very high deposition energies contribute appreciably to bismuth fission, although they are both important in uranium fission. The mean fragment velocity is found to be identical with that for uranium fission. It is concluded that the mechanism of high-energy bismuth fission is essentially indistinguishable from that operative in fission at low excitation energies generally.

Cross sections for the production of the light elements lithium, beryllium, and boron by proton bombardment of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ were measured for proton energies between 21.7 and 44.0 MeV. Time-of-flight methods were used to identify the masses of ions recoiling from a thin target into a semiconductor detector. The results are related to current models on the origin of these light elements, and are consistent with a suggestion that the ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$/${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ isotopic ratio has remained unaltered at its formation value.

Levels of the nucleus ${\mathrm{U}}^{235}$, populated in the reactions ${\mathrm{U}}^{234}(d, p){\mathrm{U}}^{235}$ and ${\mathrm{U}}^{236}(d, t){\mathrm{U}}^{235}$ induced by 12-MeV deuterons from the Argonne tandem Van de Graaff, were analyzed with a magnetic spectrograph. Most of the observed levels were identified as members of rotational bands built on the single-particle states of a deformed central field. The level assignments were made on the basis of relative populations of presumed members of each rotational band, ratios of the cross sections at 90° and 140°, and $\frac{(d, p)}{(d, t)}$ cross-section ratios. Pairing effects were calculated for the observed spectrum, and a single-particle scheme was extracted from the data. This single-particle scheme was compared with the calculations of Nilsson and Rost. Levels not predicted on the basis of the single-particle models were observed at excitations as low as 700 keV. Some of these levels, presumably vibrational excitations, were found to have cross sections comparable to those of single-particle states.

Calculations of the binding energies of $p$-shell hypernuclei have been carried out treating all the nucleons and the $\Lambda$ self-consistently. The Tabakin potential is used for the $\mathrm{NN}$ interaction and a simple central force which fits $\Lambda N$ scattering is used for the $\Lambda -N$ system. The binding energies obtained exceed those observed. The dynamical aspects of the hypernuclear system are also discussed, as well as various correction terms. Finally, a comparison is made with other hypernuclear calculations.

Isomeric states of Po isotopes from $A=204\mathrm{}$ to $A=211\mathrm{}$ have been investigated by means of the nanosecond time analysis of $\mathrm{Pb}(\alpha , xn)$ $\gamma$ rays produced in natural beam bunches of a cyclotron. In addition to those already reported, new isomeric states have been revealed systematically. The following half-lives have been measured: ${}_{}{}^{204}{}_{}{}^{}\mathrm{Po}$: 190±20 nsec; ${}_{}{}^{206}{}_{}{}^{}\mathrm{Po}$: 160±40 nsec; ${}_{}{}^{208}{}_{}{}^{}\mathrm{Po}$: 380±100 nsec; and ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$: 110±10 nsec. The possibility that such half-lives are associated with the expected 8+ state of predominant configuration ${h_{\frac{9}{2}}}^2\mathrm{}\left(p\right)\mathrm{}$ is discussed. Another half-life (24 nsec) found in ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$ was assigned as a ($h_{\frac{9}{2}}{i}_{\frac{13}{2}}$) 11 - isomeric state. Odd isotopes show three-particle isomeric states in addition to the $i_{\frac{13}{2}}\mathrm{}\left(n\right)\mathrm{}$ isomeric state. Several characteristic features revealed in this study are discussed.

Lifetimes, nuclear $g$ factors, and $\frac{E2\mathrm{}}{M1\mathrm{}}$ mixing ratios have been determined in ${\mathrm{Os}}^{192}$ and ${\mathrm{Pt}}^{192}$, and some previous determinations reevaluated. The following values have been established. For ${\mathrm{Os}}^{192}$: $g_2=+0.29\mathrm{}\pm 0.05$; $\delta \mathrm{}\left(484\right)=+{{7.6}_{-1.3\mathrm{}}}^{+2.4\mathrm{}}$. For ${\mathrm{Pt}}^{192}$: ${\tau }_2=50.0\mathrm{}\pm 3.4$ psec; ${{\tau }_2}^{\prime }=29\mathrm{}\pm 3$ psec; $g_2=+0.296\mathrm{}\pm 0.022$; ${g_2}^{\prime }=+0.29\mathrm{}\pm 0.05$; $\delta \mathrm{}\left(604\right)=+2.5\mathrm{}\pm 0.2$; $\delta \mathrm{}\left(308\right)=-{{6.3}_{-0.6\mathrm{}}}^{+0.5\mathrm{}}$. Nuclear magnetic moments are analyzed in terms of Greiner's vibrational-rotational model, transition probabilities and $\frac{E2\mathrm{}}{M1\mathrm{}}$ mixing ratios are compared to the theoretical predictions of Kumar and Baranger's model.

Independent fission yields of ${}_{}{}^{95}{}_{}{}^{}\mathrm{Zr}$ from thermal neutron fission of ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}$ and ${}_{}{}^{233}{}_{}{}^{}\mathrm{U}$ have been determined to be 0.004±0.002 and 0.034±0.006, respectively. From the values obtained, together with previously measured yields, the width of the charge dispersion for mass-95 fission products in ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}$ fission was found to be 0.53±0.03 in terms of the width parameter $\sigma$ of the normal Gaussian curve. An upper limit of 0.56 for $\sigma$ in the case of mass-95 products from ${}_{}{}^{233}{}_{}{}^{}\mathrm{U}$ fission indicates that charge dispersion in this system is similar to that for ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}$.

Independent yields of ${}_{}{}^{132}{}_{}{}^{}\mathrm{I}$, ${}_{}{}^{133}{}_{}{}^{}\mathrm{I}$, and ${}_{}{}^{134}{}_{}{}^{}\mathrm{I}$ have been measured from thermal-neutron-induced fission of ${}_{}{}^{233}{}_{}{}^{}\mathrm{U}$. The yields, each expressed as the ratio of iodine independent yield to iodine cumulative yield, are 0.06±0.03, 0.21±0.03, and 0.370±0.013 for ${}_{}{}^{132}{}_{}{}^{}\mathrm{I}$, ${}_{}{}^{133}{}_{}{}^{}\mathrm{I}$, and ${}_{}{}^{134}{}_{}{}^{}\mathrm{I}$, respectively. Values of $Z_p$ estimated from these yields with the assumption that charge distribution can be represented by a Gaussian curve with standard deviation $\sigma$ of 0.59±0.06 are ${51.58}_{-0.30\mathrm{}}^{+0.21\mathrm{}}$, ${52.02}_{-0.12\mathrm{}}^{+0.10\mathrm{}}$, and 52.33±0.03 for ${}_{}{}^{132}{}_{}{}^{}\mathrm{I}$, ${}_{}{}^{133}{}_{}{}^{}\mathrm{I}$, and ${}_{}{}^{134}{}_{}{}^{}\mathrm{I}$, respectively. The values of $Z_p$ are consistent with those previously reported for other chains in this mass region.

We report recoil angular distribution measurements from (${\mathrm{C}}^{12}$, $\mathrm{xn}$) compound-nucleus reactions with ${\mathrm{Sn}}^{118}$, ${\mathrm{Sn}}^{119}$, ${\mathrm{Sn}}^{120}$, and ${\mathrm{Sn}}^{122}$. In each case, the final product investigated was ${\mathrm{Ba}}^{126}$, corresponding to reactions in which 4, 5, 6, and 8 neutrons are emitted. The data have been analyzed to yield information on the average total energies of neutrons and photons emitted in the deexcitation of the compound nuclei. Evidence is presented for significant competition between neutron evaporation and $\gamma$-ray deexcitation processes, particularly for the $4n$ and $5n$ reactions. At the higher bombarding energies, the total energy dissipated as $\gamma$ radiation is an appreciable fraction of the available decay energy.

The ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}({}_{}{}^3{}_{}{}^{}\mathrm{He}, d){}_{}{}^{237}{}_{}{}^{}\mathrm{Np}$ and ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}(\alpha , t){}_{}{}^{237}{}_{}{}^{}\mathrm{Np}$ reactions were studied with 30-MeV ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ beams. Rotational bands built upon the following Nilsson proton configurations in ${}_{}{}^{237}{}_{}{}^{}\mathrm{Np}$ were identified: ${\frac{5}{2}}^{+}\mathrm{}\left[642\right]\mathrm{}$ (0 keV), ${\frac{5}{2}}^{-}\mathrm{}\left[523\right]\mathrm{}$ (60 keV), ${\mathrm{½}}^{-}$[530] (268 keV), ${\frac{3}{2}}^{-}\mathrm{}\left[521\right]\mathrm{}$ (514 keV). Experimental spectroscopic factors are compared with theoretical ones computed for Woods-Saxon and harmonic-oscillator-type nuclear potentials. A strong $l$ dependence of the cross-section ratio $\frac{d\sigma (\alpha , t)}{d\sigma ({}_{}{}^3{}_{}{}^{}\mathrm{He}, d)}$ has been observed.

${}_{}{}^{113m}{}_{}{}^{}\mathrm{In}$ is known to decay with a 99-min half-life predominantly by an $M4\mathrm{}$ transition of 393 keV to ${}_{}{}^{113}{}_{}{}^{}\mathrm{In}$. We find that it also decays by a weak $K$-capture branch of (0.07±0.01)% to ${}_{}{}^{113}{}_{}{}^{}\mathrm{Cd}$. Using a high-resolution Ge(Li) detector (600 eV for the ${}_{}{}^{55}{}_{}{}^{}\mathrm{Fe}$ $K$ x ray) and ${}_{}{}^{113m}{}_{}{}^{}\mathrm{In}$ sources we have carried out careful experiments which reveal the presence of Cd $K$ x rays with an intensity of 0.0024 relative to In $K$ x rays. Supporting evidence comes from the $\frac{\left(\mathrm{Cd}K\alpha \right)}{\left(\mathrm{Cd}K\beta \right)}$ ratio of 4±2, the half-life, and the observation that chemical treatment to remove Cd impurity that might be fluorescence-excited by the In $K\beta$ x rays did not affect the Cd $K$ x-ray intensity. The measured intensity corresponds to a $log\mathrm{ft}$ of 5.1±0.3. This is rather low but not unusual for a first-forbidden transition. Analysis of the effects of backscattering and collimation was crucial to the success of the experiment. The significance of the result lies in the fact that the inverse reaction ${}_{}{}^{113}{}_{}{}^{}\mathrm{Cd}+\nu \to {}_{}{}^{113m}{}_{}{}^{}\mathrm{In}+e^{-}\to {}_{}{}^{113}{}_{}{}^{}\mathrm{In}+393\mathrm{} \mathrm{keV}+e^{-}$ could serve as a possible low-threshold detector for low-energy neutrinos (<100 keV).

Excitation functions were measured for elastic and inelastic scattering of protons on a ${}_{}{}^{92}{}_{}{}^{}\mathrm{Zr}$ target in the bombarding energy range of 6.0-10.0 MeV. Inelastic groups were detected from the $2^{+}$ (0.93-MeV), $0^{+}$ (1.38-MeV), $2^{+}$ (1.85-MeV), $2^{+}$ (2.07-MeV), and $3^{-}$ (2.33-MeV) levels of ${}_{}{}^{92}{}_{}{}^{}\mathrm{Zr}$. Angular distributions taken on inelastic scattering resonances were used to identify the total angular momenta of the inelastically scattered protons. Partial widths were extracted for elastic and inelastic scattering resonances and spectroscopic factors calculated. From these, weak-coupling wave functions for several levels in ${}_{}{}^{93}{}_{}{}^{}\mathrm{Zr}$ were obtained for neutrons coupled to the various excited states of ${}_{}{}^{92}{}_{}{}^{}\mathrm{Zr}$.

Elastic and inelastic proton scattering on ${}_{}{}^{98}{}_{}{}^{}\mathrm{Mo}$ was performed over the region of excitation of isobaric analog resonances to investigate the nature of the first two excited states of ${}_{}{}^{98}{}_{}{}^{}\mathrm{Mo}$ at 0.736 MeV ($0^{+}$) and 0.787 MeV ($2^{+}$). The experiment allowed the determination of spectroscopic factors for states in ${}_{}{}^{99}{}_{}{}^{}\mathrm{Mo}$ relative to these two excited core states in ${}_{}{}^{98}{}_{}{}^{}\mathrm{Mo}$. Spectroscopic factors extracted from the elastic data are appreciably smaller than the corresponding ($d, p$) spectroscopic factors. Angular distributions taken on the inelastic scattering resonances are used to determine the $j$ value in the exit channel. The 0.736-MeV ($0^{+}$) and 0.787-MeV ($2^{+}$) states of ${}_{}{}^{98}{}_{}{}^{}\mathrm{Mo}$ are not found to be "good" core states for weak coupling.

The nucleus ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$, together with its first excited state ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$*, is treated as a three-body problem consisting of an $\alpha$ particle, a proton, and a neutron, interacting through separable potentials in pairs. The $N-N$ potential includes a tensor force in addition to a central ($S$-wave) term of the Yamaguchi type. The $p$-wave part of the $\alpha -N$ potential is parametrized in terms of the sum of a central and a small spin-orbit term which fits the experimental $P_{\frac{3}{2}}$ and $P_{\frac{1}{2}}\alpha -N$ phase shifts quite accurately. The smallness of the spin-orbit part justifies its omission from the full three-body equations. The binding energies and the wave functions for the ground ($J^P=1^{+}$) and excited ($J^P=0^{+}$) states of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ are calculated by solving the coupled Faddeev equations numerically. The calculated binding energy for the $1^{+}$ state is a little higher than, and that for the $0^{+}$ state a little lower than, the corresponding experimental values, corrected for Coulomb effects.

Activation cross sections for the ($n, 2n$) reaction in the region of $Z=40-60\mathrm{}$ at 14.4±0.3 MeV have been measured by using the mixed-powder method and Ge(Li) $\gamma$-ray detection. The total cross sections ($m+g$) measured are (in mb) ${\mathrm{Zr}}^{90}$, 652±31; ${\mathrm{Zr}}^{96}$, 1456±80; ${\mathrm{Mo}}^{92}$, 217±18; ${\mathrm{Mo}}^{100}$, 1389±84; ${\mathrm{Ru}}^{96}$, 569±30; ${\mathrm{Ru}}^{98}$, 1168±96; ${\mathrm{Ru}}^{104}$, 1440±80; ${\mathrm{Rh}}^{103}$, 957±57; ${\mathrm{Pd}}^{102}$, 637±45; ${\mathrm{Pd}}^{110}$, 1416±150; ${\mathrm{Cd}}^{108}$, 865±100; ${\mathrm{Cd}}^{110}$, 1221±150; ${\mathrm{Cd}}^{116}$, 1389±71; ${\mathrm{Sn}}^{114}$, 1239±130; ${\mathrm{Sb}}^{121}$, 1615±63; ${\mathrm{Sb}}^{123}$, 1542±80; ${\mathrm{Te}}^{122}$, 1615±110; ${\mathrm{Te}}^{128}$, 1661±161; ${\mathrm{Te}}^{130}$, 1455±55; ${\mathrm{I}}^{127}$, 1649±80; ${\mathrm{Cs}}^{133}$, 1542±75; ${\mathrm{Ba}}^{132}$, 1574±100; ${\mathrm{Ce}}^{136}$, 1318±90; ${\mathrm{Ce}}^{140}$, 1593±130; and ${\mathrm{Ce}}^{141}$, 1730±170. Some partial ($n, 2n$) cross sections also are reported. The measured values are compared with the semiempirical predictions of Pearlstein and of Gardner. No significant shell effects are seen, and the data suggest that 14-MeV ($n, 2n$) reactions are governed predominantly by the statistical model of the compound nucleus. An empirical fit for the ratio of neutron emission to all modes of compound-nucleus decay, $\frac{{\sigma }_{n,M}}{{\sigma }_{\mathrm{ne}}}$, is deduced from the present results.

The following activation cross sections (in mb) for the ($n, p$), [$(n, np)+(n, pn)+(n, d)$] and ($n, \alpha$) reactions in the region of $Z=40-58\mathrm{}$ have been determined at 14.4±0.3 MeV by using the mixed powder method with Ge(Li) $\gamma$-ray detection: ${\mathrm{Zr}}^{90}(n, p){\mathrm{Y}}^{90m}$ (3.1 h), 12.9±1.0; ${\mathrm{Zr}}^{91}(n, p){\mathrm{Y}}^{91m}$ (50.3 min), 18.6±1.9; ${\mathrm{Zr}}^{92}(n, p){\mathrm{Y}}^{92}$ (3.53 h), 18.5±2.7; ${\mathrm{Mo}}^{92}(n, p){\mathrm{Mb}}^{92m}$ (10.1 day), 62.5±4.0; ${\mathrm{Mo}}^{96}(n, p){\mathrm{Nb}}^{96}$ (23.35 h), 21.3±1.5; ${\mathrm{Mo}}^{97}(n, p){\mathrm{Nb}}^{97m}$ (1 min), 7.4±0.8; ${\mathrm{Mo}}^{97}(n, p){\mathrm{Nb}}^{97g}$ (72 min), 8.5±1.0; ${\mathrm{Mo}}^{98}(n, p){\mathrm{Nb}}^{98g}$ (51 min), 4.1±0.5; ${\mathrm{Ru}}^{96}(n, p){\mathrm{Tc}}^{96}$ (4.35 day), 146±7; ${\mathrm{Rh}}^{103}(n, p){\mathrm{Ru}}^{103}$ (39.5 day), 16.9±1.5; ${\mathrm{Pd}}^{105}(n, p){\mathrm{Rh}}^{105}$ (35.9 h), 37.6±2.0; ${\mathrm{Pd}}^{106}(n, p){\mathrm{Rh}}^{106m}$ (130 min), 6.0±0.4; ${\mathrm{Pd}}^{106}(n, p){\mathrm{Ru}}^{106g}$ (30 sec), 18±4; ${\mathrm{Pd}}^{108}(n, p){\mathrm{Rh}}^{108}$ (16.8 sec), 8.3±1.5; ${\mathrm{Cd}}^{112}(n, p){\mathrm{Ag}}^{112}$ (3.14 h), 15.0±1.3; ${\mathrm{Sn}}^{116}(n, p){\mathrm{In}}^{116m}$ (54 min), 7.9±0.8; ${\mathrm{Sn}}^{117}(n, p){\mathrm{In}}^{117m}$ (1.93h), 5.7±1.5; ${\mathrm{Sn}}^{117}(n, p){\mathrm{In}}^{117g}$ (45 min), 9.8±1.6; ${\mathrm{Ba}}^{138}(n, p){\mathrm{Cs}}^{138}$ (32.2 min), 3.8±0.6; ${\mathrm{Ce}}^{140}(n, p){\mathrm{La}}^{140}$ (40.22 h), 6.3±0.5; ${\mathrm{Zr}}^{94}(n, \alpha ){\mathrm{Sr}}^{91}$ (9.67 h), 5.0±1.0; ${\mathrm{Nb}}^{93}(n, \alpha ){\mathrm{Y}}^{90m}$ (3.1 h), 5.3±0.5; ${\mathrm{Mo}}^{92}(n, \alpha ){\mathrm{Zr}}^{89m}$ (4.18 min), 9.4±0.9; ${\mathrm{Mo}}^{92}(n, \alpha ){\mathrm{Zr}}^{89g}$ (78.4 h), 18.7±1.5; ${\mathrm{Mo}}^{98}(n, \alpha ){\mathrm{Zr}}^{95}$ (65.5 day), 8.1±1.0; ${\mathrm{Pd}}^{106}(n, \alpha ){\mathrm{Ru}}^{103}$ (39.5 day), 5.6±0.7; ${\mathrm{Pd}}^{108}(n, \alpha ){\mathrm{Ru}}^{105}$ (4.44 h), 2.7±0.3; ${\mathrm{Cs}}^{133}(n, \alpha ){\mathrm{I}}^{130}$ (12.3 h), 1.96±0.15; ${\mathrm{Ba}}^{138}(n, \alpha ){\mathrm{Xe}}^{135m}$ (15.6 min), 0.55±0.05; ${\mathrm{Ba}}^{138}(n, \alpha ){\mathrm{Xe}}^{135g}$ (9.14 h), 2.0±0.2; ${\mathrm{Ce}}^{142}(n, \alpha ){\mathrm{Ba}}^{139}$ (82.9 min), 6.0±1.0; ${\mathrm{Ru}}^{96}\left[\right(n, np)+(n, pn)+(n,d\left)\right]{\mathrm{Tc}}^{95m}$ (61.0 day), 52±10; and ${\mathrm{Ru}}^{96}\left[\right(n, np)+(n, pn)+(n, d\left)\right]{\mathrm{Tc}}^{95g}$ (20 h), 483±50. The total ($n, p$) cross sections are compared with Levkovskii's predictions and show good agreement. The relative ($n, p$) cross sections of Mo and Pd also are compared with Gardner's predictions.

Assuming isospin conservation, we perform an analysis of the two-nucleon transfer reactions ($p, t$) and ($p$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$) on a target with isospin $T_i$ going to analog final states with $T_f=T_i$. Formulas for the relevant cross sections are given which explicitly show the isospin dependence of the transferred pair. When restricted to $T=1\mathrm{}$ pair transfer, our result is more general than that recently derived by Hardy, Brunnader, and Cerny.

The single-particle energy states of neutrons calculated for several finite nuclei are found in good agreement with the experimental data. An effective velocity-dependent nucleon-nuclear potential based upon the $N-N$ interaction has been employed in the independent-particle model, and the spin-orbit effect has been studied.