Gamma-ray angular correlations have been measured for the 316-469, 413-263, 393-263, and 875-469 keV cascades in ${}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}$ following the decay of ${}_{}{}^{105}{}_{}{}^{}\mathrm{Ru}$. Spin-parity assignments in ${}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}$ are established as ${3/2}^{+}$ for the 469-keV level and ${5/2}^{-}$ for the 786-keV level, and the present data are consistent with ${3/2}^{+}$ assignments for both the 806- and 1345-keV levels. Based on these assignments we find the $\frac{E2\mathrm{}}{M1\mathrm{}}$ mixing rations to be $\delta \mathrm{}\left(263\right)=-0.27\mathrm{}\pm 0.04$, $\delta \mathrm{}\left(393\right)=-0.30\mathrm{}\pm 0.02$, and $\delta \mathrm{}\left(875\right)={+1.3\mathrm{}}_{-0.4\mathrm{}}^{+0.6\mathrm{}}$.

RADIOACTIVITY ${}_{}{}^{105}{}_{}{}^{}\mathrm{Ru}$ [from ${}_{}{}^{104}{}_{}{}^{}\mathrm{Ru}(n,\gamma )$]; measured $\gamma \gamma \left(\theta \right)$; deduced ${}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}$ spin assignments $I^{\pi }$ for 469-, 786-, 806-, and 1345-keV levels; deduced ${}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}$ $\gamma$-ray mixing ratios $\delta \mathrm{}\left(263\right)\mathrm{}$, $\delta \mathrm{}\left(393\right)\mathrm{}$, $\delta \mathrm{}\left(875\right)\mathrm{}$.

The decay of ($J^{\pi }$ in parentheses) ${}_{}{}^{52}{}_{}{}^{}\mathrm{V}$($3^{+}$), ${}_{}{}^{52}{}_{}{}^{}\mathrm{Mn}_{}^m{}_{}{}^{}\left(2^{+}\right)$, and ${}_{}{}^{52}{}_{}{}^{}\mathrm{Mn}_{}^g{}_{}{}^{}\left(6^{+}\right)$ has been studied in order to clarify the number and nature of levels in ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$ below 5 MeV. The levels of ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$ that are populated in these $\beta$ decays are ($J^{\pi }$ in parentheses) ground state ($0^{+}$), 1434.08 ($2^{+}$), 2369.60 ($4^{+}$), 2767.68 ($4^{+}$), 2964.77 ($2^{+}$), 3113.82 ($6^{+}$), 3161.63 ($2^{+}$), 3415.27 ($4^{+}$), 3472.2 ($3^{+}$), 3615.84 ($5^{+}$), 3771.8 ($2^{+}$), 3951 (($1^{+}$)), 4015.42 ($5^{+}$), (4208 (-)), 4563 ($3^{-}$), 4627.1 ($5^{+}$), and 4815.7 keV ($2^{+}$). A single level at 3472.2 keV ($3^{+}$) replaces the previously proposed doublet at 3469 and 3473 keV.

RADIOACTIVITY Chemically separated sources; measured $E_{\gamma }$, $I_{\gamma }$, deduced ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$ levels $J$, $\pi$; Compton suppression.

Directional correlations and polarization-directional correlations have been measured for several $\gamma -\gamma$ cascades in ${}_{}{}^{94}{}_{}{}^{}\mathrm{Mo}$ populated from the decay of ${}_{}{}^{94}{}_{}{}^{}\mathrm{Tc}_{}^g{}_{}{}^{}$. NaI(Tl)-Ge(Li) detectors were used in both experiments. Combination of the results of those measurements gives unique spin-parity assignments of $6^{+}$ for both the 2872.5 and 3339.5 keV levels. The determined $\frac{E2\mathrm{}}{M1\mathrm{}}$ mixing ratios are $\delta \mathrm{}\left(449\right)={-0.04\mathrm{}}_{-0.04\mathrm{}}^{+0.08\mathrm{}}$, $\delta \mathrm{}\left(742\right)=0.65\mathrm{}\pm 0.15$, and $\delta \mathrm{}\left(916\right)=-0.04\mathrm{}\pm 0.04$.

RADIOACTIVITY ${}_{}{}^{94}{}_{}{}^{}\mathrm{Tc}$ from ${}_{}{}^{93}{}_{}{}^{}\mathrm{Nb}(\alpha ,3n)$; measured $\gamma \gamma \mathrm{}\left(0\right)\mathrm{}$ and $\gamma \gamma \left(90\mathrm{} \mathrm{LP}\right)$ (Linearpolarization correlation). Deduced $J^{\pi }$ $\delta \left(\frac{E2\mathrm{}}{M1\mathrm{}}\right)$. Ge(Li) and NaI(Tl) detectors.

In-beam time-sorted measurements of internal-conversion electrons, $\gamma$ rays, and $\gamma -\gamma$ coincidence are reported for ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$. The range of measurable kinetic energies of electrons was ∼40-1600keV with powder targets using the reaction ${}_{}{}^{204}{}_{}{}^{}\mathrm{Hg}(\alpha ,2\mathrm{}n){}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$. The results confirm the yrast 12+, 10+, and 9- levels in ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$ which, based on partial evidence, were tentatively proposed by the group in Stockholm. The effective quadrupole charge of the $i_{\frac{13}{2}}$ neutron is (0.89 ± 0.05)e. Conversion coefficients and multipolarities of 10 transitions in ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$ are reported.

NUCLEAR REACTIONS ${}_{}{}^{204}{}_{}{}^{}\mathrm{Hg}(\alpha ,2\mathrm{}n)$, $E_{\alpha }=30\mathrm{}$ MeV; measured 40-1600 keV internal conversion electron spectra, $\gamma$ spectra, and $\gamma -\gamma$ coincidence spectra in eight time bands after beam burst. Deduced levels, $J$, $\pi$, ICC. Si(Li) and Ge(Li) detectors.

We have measured the $g$ factor of the ${3/2}^{+}$ hole state in ${}_{}{}^{43}{}_{}{}^{}\mathrm{Sc}$. This state, which has an excitation energy of 152 keV and a mean life of 632 μs, has $g=+0.232\mathrm{}\pm 0.004$. The result is consistent with an earlier mesurement for a similar state in ${}_{}{}^{47}{}_{}{}^{}\mathrm{Sc}$ and requires modification of a model earlier developed to explain the large inhibition in the decay of these states.

NUCLEAR MOMENTS ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}(\alpha ,p)$, $E_{\alpha }=20\mathrm{}$ MeV, pulsed beam, measured $I_{\gamma }(\theta ,B,t)$ for $E_{\gamma }=152\mathrm{}$ keV, spin rotation; deduced $g$, relaxation time.

On the assumption that the most important configurations in the description of the ${3/2}^{+}$-hole states in ${}_{}{}^{43}{}_{}{}^{}\mathrm{Sc}$ and ${}_{}{}^{47}{}_{}{}^{}\mathrm{Sc}$ are ${[{\left(\pi d_{\frac{3}{2}}\right)}^{-1\mathrm{}}\times {}_{}{}^{A+1}{}_{}{}^{}\mathrm{Ti}\mathrm{}(I\left)\right]}_{\left(\frac{3}{2}\right)m}(I=0^{+} \mathrm{and} 2^{+})$ and ${[{\left(\pi s_{\frac{1}{2}}\right)}^{-1\mathrm{}}\times {}_{}{}^{A+1}{}_{}{}^{}\mathrm{Ti}(2^{+}\left)\right]}_{\left(\frac{3}{2}\right)m}$ empirical wave functions are deduced that fit both the magnetic moments and the severely inhibited $M2\mathrm{}$ decays of the states. The data require a 10-15% admixture of the $\pi s_{\frac{1}{2}}$ hole. The fitted wave functions are compared with the shell-model eigenfunctions that are obtained when the model space consists of nucleons in the $1f_{\frac{7}{2}}$ shell and a single hole in either the $1d_{\frac{3}{2}}$ or $2s_{\frac{1}{2}}$ orbits. Although the shell-model wave functions are very similar to the empirical ones [the probability ${\left|〈\psi \right(\mathrm{fit}\left)\right|\psi \mathrm{}\left(\mathrm{sm}\right)\mathrm{}〉|}^2$ is at least 0.94], the experimental data are not extremely well reproduced with these wave functions. The implications of this result are discussed in detail. Considering the fact that the values of the quantities to be described are anomalously small we conclude that this model space provides an adequate description of the ${3/2}^{+}$ states in question. The magnetic moment of the $d_{\frac{3}{2}}$ hole state in ${}_{}{}^{45}{}_{}{}^{}\mathrm{Ti}$ is calculated on the basis of the shell model and shown to be in agreement with a recent experiment.

NUCLEAR STRUCTURE Shell-model calculation for magnetic moments and $M2\mathrm{}$ decays of the ${\frac{3}{2}}^{+}$-hole states in ${}_{}{}^{43}{}_{}{}^{}\mathrm{Sc}$, ${}_{}{}^{47}{}_{}{}^{}\mathrm{Sc}$, and ${}_{}{}^{45}{}_{}{}^{}\mathrm{Ti}$.

The pairing-vibration model with isospin is extended to include $\alpha$-transfer reactions. Selection rules and expressions for transition strengths are derived and compared with experimental results for $A=40\mathrm{}-66$ nuclei. The selection rules are found to be followed quite well in the examples studied. The systematics of ground-state transition strengths are qualitatively quite well reproduced although the quantitative agreement is poor. When the changing nature of the pairing quanta is incorporated using two-particle transfer data the agreement becomes quantitatively good. Evidence is presented for clustering other than that due to pairing in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{44}{}_{}{}^{}\mathrm{Ti}$.

NUCLEAR STRUCTURE Extension of pairing-vibration model to four-particle transfer reactions and comparison with experimental results for $f-p$ shell nuclei.

A collective model which incorporates vibrations and rotations of a permanently deformed nucleus is applied to ${}_{}{}^{102}{}_{}{}^{}\mathrm{Pd}$, ${}_{}{}^{104}{}_{}{}^{}\mathrm{Pd}$, ${}_{}{}^{106}{}_{}{}^{}\mathrm{Pd}$, ${}_{}{}^{108}{}_{}{}^{}\mathrm{Pd}$, ${}_{}{}^{110}{}_{}{}^{}\mathrm{Pd}$, ${}_{}{}^{112}{}_{}{}^{}\mathrm{Pd}$, and ${}_{}{}^{114}{}_{}{}^{}\mathrm{Pd}$. Theoretical energy levels are compared with those from experiment and remarkably good agreement is found. The model wave functions are further tested via $B\left(E2\right)$ ratios and agreement with experiment is very good. An unidentified extra degree of freedom is treated essentially by ansatz but a discussion of the possible origin of that degree of freedom is given. Trends in the model parameters are shown and the conclusion drawn that to a good approximation the states of these even-mass Pd isotopes are well described as those of collective rotations and vibrations.

NUCLEAR STRUCTURE ${}_{}{}^{102,104,106,108,110,112,114}{}_{}{}^{}\mathrm{Pd}$. Theory, collective rotational and vibrational motion; calculated energy levels. $B\left(E2\right)$ ratios.

The exact norms of the multiphonon states built upon a $K^{\pi }=0^{+}$ collective deformed phonon are derived. Comparison with various approximations are carefully analyzed and the role of the Pauli principle is emphasized.

NUCLEAR STRUCTURE Norms of multiphonon $K^{\pi }=0^{+}$ states in deformed nuclei. Exact and approximate expressions.

Generalized Hartree-Fock Overhauser orbitals, corresponding to a (zero pressure) periodic structure of $\alpha$ particles, are shown to have lower energy than homogeneous nuclear matter with a Skyrme interaction, at subnuclear densities.

NUCLEAR STRUCTURE Nuclear matter, Hartree-Fock approximation, cluster models.

A shell model calculation is performed for the $\mathrm{sd}$ shell nuclei with mass numbers $18\le A\le 20$ and $36\le A\le 38$. The energy spectra of the lower and upper $\mathrm{sd}$ shell regions can be well reproduced simultaneously using a mass-dependent single effective interaction.

NUCLEAR STRUCTURE Calculated energy levels and effective interactions, shell model.

We discuss the equation of motion $〈{\psi }_{\hat{B}}\left|\right[H,a_{\alpha }\left]\right|{\psi }_0〉=(E_{\hat{B}}-E_0) 〈{\psi }_{\hat{B}}\left|a_{\alpha }\right|{\psi }_0〉$ in the subspace of states $|{\psi }_{\hat{B}}〉=\Sigma {\alpha }^{}{\beta }_{\alpha }{a}_{\alpha }|{\psi }_0〉$, where $|{\psi }_0〉$ is the correlated ground state of a double magic nucleus. It is shown that this equation can be solved with high accuracy if some low-order correlation functions of the $\exp S$ theory are known. Preliminary results are given for ${}_{}{}^3{}_{}{}^{}\mathrm{H}$ and ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ for four different nucleon-nucleon interactions, i.e., the Reid-soft-core potential with and without the three-body correction of Blatt and McKellar, the Hamada-Johnston potential, and the de Toureill-Sprung supersoft-core potential. The connection with shell model states is discussed.

NUCLEAR STRUCTURE ${}_{}{}^3{}_{}{}^{}\mathrm{H}$, ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$, ${}_{}{}^{15}{}_{}{}^{}\mathrm{O}$ calculated hole states ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$. Centroid energies from microscopic theory.

A new model for the ${}_{}{}^4{}_{}{}^{}\mathrm{H}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{Li}$ nuclei in which structure and reaction aspects are treated on an equal footing is introduced. The internal states are expanded on a basis of properly antisymmetrized translationally invariant harmonic oscillator eigenstates including all states up to $4\hslash \omega$ oscillator excitation. All two-body breakup channels, namely $n+{}_{}{}^3{}_{}{}^{}\mathrm{H}$ or $p+{}_{}{}^3{}_{}{}^{}\mathrm{He}$, are explicitly included. The two-body interaction is based on the Sussex matrix elements. Model widths and positions of the excited states and elastic scattering cross sections are in qualitative agreement with the data. Three- and four-body breakup channels are ignored.

NUCLEAR STRUCTURE Calculated ${}_{}{}^4{}_{}{}^{}\mathrm{H}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{Li}$ level positions and widths.

NUCLEAR REACTIONS Calculated differential cross sections for ${}_{}{}^3{}_{}{}^{}\mathrm{H}\mathrm{}(n,n)\mathrm{}$ and ${}_{}{}^3{}_{}{}^{}\mathrm{He}\mathrm{}(p,p)\mathrm{}$ for $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=5.1\mathrm{}-8.1$ MeV.

Clarifications have been provided regarding the remarks made by Gibson and Lehman concerning our results on the $\Lambda$ separation energy ($B_{\Lambda }$) in ${}_{\Lambda }{}^3{}_{}{}^{}\mathrm{H}$.

NUCLEAR STRUCTURE ${}_{\Lambda }{}^3{}_{}{}^{}\mathrm{H}$, $Y-N$ potentials, separable potential three-body calculation, $B_{\Lambda }$.

It is pointed out that the conclusions of the preceding comment are in error.

NUCLEAR STRUCTURE ${}_{\Lambda }{}^3{}_{}{}^{}\mathrm{H}$, $Y-N$ potentials, separable-potential three-body calculations, $B_{\Lambda }$.

The use of incident polarized protons to distinghish between different models for backward inclusive proton production from nuclei is discussed.

NUCLEAR REACTIONS Polarized protons, inclusive scattering from nuclei.

The half-life of ${}_{}{}^{52}{}_{}{}^{}\mathrm{Mn}$ has been measured to be 5.59 ± 0.01 days.

RADIOACTIVITY ${}_{}{}^{52}{}_{}{}^{}\mathrm{Mn}_{}^g{}_{}{}^{}$; measured $T_{\frac{1}{2}}$.

Levels of ${}_{}{}^{16}{}_{}{}^{}\mathrm{F}$ have been investigated by means of the ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$(${}_{}{}^3{}_{}{}^{}\mathrm{He}$, ${}_{}{}^6{}_{}{}^{}\mathrm{He}$) reaction at 70 MeV bombarding energy and the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}({}_{}{}^3{}_{}{}^{}\mathrm{He},t)$ reaction at 35 MeV. Three new states at 4.71, 6.05, and 6.93 MeV have been found.

NUCLEAR REACTIONS ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$(${}_{}{}^3{}_{}{}^{}\mathrm{He}$, ${}_{}{}^6{}_{}{}^{}\mathrm{He}$), $E_{{}_{}{}^3{}_{}{}^{}\mathrm{He}}=70\mathrm{}$ MeV, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}({}_{}{}^3{}_{}{}^{}\mathrm{He},t)$, $E_{{}_{}{}^3{}_{}{}^{}\mathrm{He}}=35\mathrm{}$ MeV. ${}_{}{}^{16}{}_{}{}^{}\mathrm{F}$ deduced levels.

Model-dependent deformation parameters, ${\beta }_{20}$ and ${\beta }_{40}$ are extracted from measured $E2\mathrm{}$ and $E4\mathrm{}$ transition moments for a distribution of nuclear charge represented by a three-parameter deformed Fermi distribution with a parabolic center depression. For the thorium and uranium nuclei this shape of the charge distribution reduces the extracted values of ${\beta }_{20}$ by 5-10% and ${\beta }_{40}$ by 10-15% from the values obtained with a two-parameter deformed Fermi distribution.

NUCLEAR STRUCTURE Extracted model-dependent deformation parameters ${\beta }_{20}$ and ${\beta }_{40}$.

A new resonance peak has been found at 14.7 ± 0.2 MeV in spectra of inelastic electrons scattered from ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}$. The peak exhausts a significant part of the $E0\mathrm{}$ sum rule and is characterized by a narrow width of about 2.1 MeV. The giant quadrupole resonances splits into two peaks at 9.5 ± 0.2 and 11.3 ± 0.2 MeV which deplete (29 ± 5)% and (63 ± 8)% of the isoscalar $E2\mathrm{}$ energy-weighted sum rule, respectively.

NUCLEAR REACTIONS ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}(e,e^{\prime })$, measured ($E_{e^{\prime }},{\theta }_{e^{\prime }}$), $E_x=0\mathrm{}-30$ MeV, reduced $B\left(E0\mathrm{}\right)\mathrm{}$, $B\left(E2\mathrm{}\right)\mathrm{}$ for giant resonances.