The level structure of ${}_{}{}^{199}{}_{}{}^{}\mathrm{Au}$ was investigated via the ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$(t,p) reaction induced with a 17 MeV triton beam. Essentially all of the $L=0\mathrm{}$ transfer strength is observed in the ground state transition. The distribution of $L=4\mathrm{}$ transfer strength follows the systematic behavior observed previously in the Pt(t,p) reactions.

NUCLEAR REACTIONS ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$(t,p), $E=17\mathrm{}$ MeV; measured energy levels, $\sigma \left(\theta \right)$ in ${}_{}{}^{199}{}_{}{}^{}\mathrm{Au}$; distorted wave Born approximation calculations.

The Feshbach effective Hamiltonian for unsymmetrized rearrangement channels is used to obtain coupled reaction channels equations with effective interactions. Operators are introduced which solve nonorthogonality to all orders. Two representations of the effective Schrödinger equation are obtained with solved nonorthogonality. These equations have unique solutions, even when the basis used is overcomplete. The effective interactions in these equations are compared with those defined by Goldflam and Kowalski. Implications for the coupled reaction channels method are discussed.

NUCLEAR REACTIONS Feshbach formalism for rearrangement channels. Coupled reaction channels. Nonorthogonality and overcomplete bases. Effective interactions.

An optical model analysis of results from a program of neutron time-of-flight measurements of elastic scattering from the $1-p$ shell nuclei is described. Experiments have been carried out at the TUNL FN Tandem van de Graaff facility using the ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(d,n)${}_{}{}^3{}_{}{}^{}\mathrm{He}$ reaction as a neutron source. Experimental methods and past results for neutron scattering from ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$, ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$, and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ are summarized. Data have generally been accumulated at bombarding energies from 7 to 15 MeV in 1-MeV steps, at scattering angles from 25° to 160°. Cross sections are compared to previous work. Much of the neutron scattering data is well described by the spherical optical model, particularly for nuclei in which resonance structure is not prominent. However, spherical optical model parameters for heavier nuclei do not reproduce the data well. Parameter sets for the individual nuclei are presented along with the results of a global spherical optical model search over 45 neutron scattering angular distributions for all $1-p$ shell nuclei. Volume integrals for the real and imaginary wells are compared to recent theoretical predictions. The spherical optical model predictions for proton elastic scattering are compared to the available data for the $T=0\mathrm{}$ nuclei. Coulomb correction terms to the real and imaginary potential well depths are investigated.

NUCLEAR REACTIONS ${}_{}{}^{6,7}{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{10,11}{}_{}{}^{}\mathrm{B}$, ${}_{}{}^{12,13}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$(n,n), measured $\sigma \left(\theta \right)$, $E=7-15\mathrm{}$ MeV, deduced spherical optical model parameters.

The low energy cross section for the ${}_{}{}^7{}_{}{}^{}\mathrm{Be}(\mathrm{p}, \gamma ){}_{}{}^8{}_{}{}^{}\mathrm{B}$ reaction has been measured by detecting the delayed $\alpha$ particles from the ${}_{}{}^8{}_{}{}^{}\mathrm{B}$ beta decay. Detailed discussion is presented of the analysis of the radioactive ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ target including the use of two independent methods to determine the ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ areal density. The direct capture part of the cross section is subtracted from the total cross section to deduce resonance parameters for the $1^{+}$ first excited state in ${}_{}{}^8{}_{}{}^{}\mathrm{B}$. The zero-energy astrophysical $S$ factor inferred from the present experiment is compared with previous values. The effect on the ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$ solar neutrino capture rate, predicted by the standard solar model, is also discussed.

The transverse polarization transfer coefficient $K_y^{y^{\prime }}$ has been measured for the reaction ${}_{}{}^1{}_{}{}^{}\mathrm{H}(\overrightarrow{\mathrm{d}}, \overrightarrow{\mathrm{n}})\mathrm{pp}$ at 0° for $E_{\mathrm{d}}=42.8\mathrm{}$ MeV as a function of breakup neutron energy. For the high-energy neutrons ($E_{\mathrm{n}}>28\mathrm{}$ MeV) the average value for $K_y^{y^{\prime }}$ is close to 0.6, in conformity with the prediction of a simple stripping or spectator model for polarization transfer in deuteron stripping reactions. Good agreement is found with available Faddeev calculations.

NUCLEAR REACTIONS ${}_{}{}^1{}_{}{}^{}\mathrm{H}(\overrightarrow{\mathrm{d}}, \overrightarrow{\mathrm{n}})\mathrm{pp}$, $E_{\mathrm{d}}=42.8\mathrm{}$ MeV; measured $K_y^{y^{\prime }}$ for ${\theta }_{\mathrm{lab}}=0\mathrm{}°$; stripping model; Faddeev calculations.

Differential cross sections for ${}_{}{}^3{}_{}{}^{}\mathrm{He}(\gamma , \mathrm{d}){}_{}{}^1{}_{}{}^{}\mathrm{H}$ for incident energies between 150 and 350 MeV at center-of-mass proton angles near 60° and 90° have been measured with an absolute uncertainty of less than 6%. The experiment used a single-arm spectrometer, a gas target, and an uncollimated bremsstrahlung beam. The results are in good agreement with new measurements of the time-reversed reaction, ${}_{}{}^2{}_{}{}^{}\mathrm{H}(\mathrm{p}, {}_{}{}^3{}_{}{}^{}\mathrm{He})\gamma$, giving no evidence for a violation of time-reversal invariance. The differential cross sections decrease smoothly with energy and show only a small contribution from the $\Delta \mathrm{}\left(1232\right)\mathrm{}$ resonance.

NUCLEAR REACTIONS ${}_{}{}^3{}_{}{}^{}\mathrm{He}(\gamma , \mathrm{d}){}_{}{}^1{}_{}{}^{}\mathrm{H}$, $E_0=150-350\mathrm{}$ MeV; measured $\frac{d\sigma }{d\Omega }$ at ${\theta }_{\mathrm{p}}(\mathrm{c}.\mathrm{m}.\mathrm{})\cong 60°, 90°$; tested detailed balance and time-reversal invariance.

Neutron elastic and inelastic scattering cross sections have been measured for 60.5 keV neutrons incident on ${}_{}{}^{187,188}{}_{}{}^{}\mathrm{Os}$. For ${}_{}{}^{187}{}_{}{}^{}\mathrm{Os}$ the cross section for elastic scattering is 11 b and for inelastic scattering to the 9.75-keV level it is 1.13 b. These results and other scattering properties are represented in phase shift and scattering potential analyses, which then allow the prediction of neutron capture by ${}_{}{}^{187}{}_{}{}^{}\mathrm{Os}$ nuclei in the 9.75-keV and ground levels. Capture rates thus provided are used in the Re-Os nucleochronology, and lead to a long galactic age, about 18 to 20 Gyr.

NUCLEAR REACTIONS ${}_{}{}^{187,188}{}_{}{}^{}\mathrm{Os}$(n,n) and ${}_{}{}^{187}{}_{}{}^{}\mathrm{Os}$(n,′n), $E_{\mathrm{n}}=60.5\mathrm{}$ keV; measured $\sigma \left(\theta \right)$; phase shift and potential analyses; deduced galactic age of 18 to 20 Gyr.

Excited neutron rotational levels have been observed in ${}_{}{}^{180}{}_{}{}^{}\mathrm{Ta}$ up to an excitation energy of 1 MeV using the ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}$(d,t)${}_{}{}^{180}{}_{}{}^{}\mathrm{Ta}$ reaction. New assignments have been proposed for levels in the ${\frac{7}{2}}^{+}{\mathrm{}\left[404\right]\mathrm{}}_{\pi }\pm {\frac{1}{2}}^{-}{\mathrm{}\left[521\right]\mathrm{}}_{\nu }$ and ${\frac{7}{2}}^{+}\mathrm{}\left[404\right]\mathrm{}\pm {\frac{7}{2}}^{-}\mathrm{}\left[514\right]\mathrm{}$ configurations. Levels in the latter are discussed with regard to configuration mixing between low energy $K^{\pi }=8^{+}$ bands expected in ${}_{}{}^{180}{}_{}{}^{}\mathrm{Ta}$.

NUCLEAR REACTIONS ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}$(d,t)${}_{}{}^{180}{}_{}{}^{}\mathrm{Ta}$ with natural tantalum oxide target; $E_{\mathrm{d}}=17.4\mathrm{}$ MeV; measured $E_{\mathrm{t}}$ and $\sigma \left(\theta \right)$ with QDDD spectrometer; DWBA analysis; deduced levels $I^{\pi }$, $K$.

NUCLEAR STRUCTURE ${}_{}{}^{180}{}_{}{}^{}\mathrm{Ta}$ assigned Nilsson configurations; failure to observe configuration mixing between expected low energy $K^{\pi }=8^{+}$ bands.

Differential cross sections for elastic scattering of neutrons from ${}_{}{}^{54,56}{}_{}{}^{}\mathrm{Fe}$ have been measured at several energies in the 20-26 MeV region. The data have been analyzed both in terms of the standard phenomenological optical model, and in the framework of two different microscopic models based upon nuclear matter calculations using realistic nucleon-nucleon interactions and a local density approximation. Isospin consistency of the microscopic-model calculations was also tested by analyzing proton elastic differential cross section data in the same energy region, as well as both proton and neutron elastic analyzing power data. The microscopic calculations yield quite reasonable agreement with the data, even though they contain no free geometrical parameters. The quality of the results for the analyzing power data is particularly impressive, indicating that the very simple, density- and energy-independent spin-orbit force used in the calculations is sufficient. The differences between the various models are clarified by examining the momentum-space representations of the potentials.

NUCLEAR REACTIONS ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$(n,n) $E_{\mathrm{n}}=20, 22, 24, \mathrm{and} 26$ MeV, ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$(n,n) $E_{\mathrm{n}}=20, 26$ MeV. Measured $\left(\frac{d\sigma }{d\Omega }\right)\left(\theta \right)$. Calculated optical model potentials. Microscopic analysis.

The ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}(\alpha , \mathrm{n}){}_{}{}^{51}{}_{}{}^{}\mathrm{Cr}$ and ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}(\alpha , \mathrm{n}){}_{}{}^{54}{}_{}{}^{}\mathrm{Mn}$ cross sections were measured in the energy range 6-13 MeV to an accuracy of about 3%. The activation method was used for the determination of the reaction yields, and the product of incident flux and target thickness was determined from measurements of Rutherford scattering. Using known information on the competing charged-particle emission and extensive statistical model calculations, the total reaction cross sections for $\alpha$ particles on ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}$ and ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}$ could be derived with similar accuracy. Especially at lower energies our results are considerably smaller than the predictions of the widely-used Huizenga-Igo optical potential and support the potential of McFadden and Satchler.

NUCLEAR REACTIONS ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}(\alpha , \mathrm{n})$, $E_{\alpha }=6\mathrm{} \mathrm{to} 13$ MeV; ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}(\alpha , \mathrm{n})$, $E_{\alpha }=6.5\mathrm{} \mathrm{to} 12$ MeV; measured yield of residual nuclides; deduced total $\alpha$-reaction cross sections. Comparison with optical model calculations.

A large body of photonuclear-reaction data has been compared with predictions of the hybrid-plus-evaporation model. The data are for monoenergetic photons of energy from 25 to 132 MeV on ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, Sn, Ce, Ta, and Pb targets, measured by the Saclay group. A quasideuteron absorption mechanism was assumed to give the primary excitation, and the hybrid-plus-evaporation model was used to predict the excitation functions, the neutron-emission widths and multiplicities, and the number of fast neutrons and protons emitted per absorbed photon versus photon energy for Sn, Ce, Ta, and Pb. The parameters used in the calculations were the global set recently selected for nucleon-induced reactions. The calculated results are in excellent agreement with the experimental data over the entire energy range. Additional experiments are suggested in order to make possible stricter tests of the precompound-decay models to provide further information on the details of the primary excitation process.

NUCLEAR REACTIONS Photonuclear yield data for ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, Sn, Ce, Ta, Pb targets, 25- to 132-MeV photons, analyzed using hybrid precompound-plus-evaporation model assuming quasideuteron absorption mechanism.

Differential cross sections $\sigma (Z, A, E, \theta )$ for the quasielastic projectilelike reaction products from the bombardment of ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$ on ${}_{}{}^{58,64}{}_{}{}^{}\mathrm{Ni}$ and ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}$ at 5.9 and 8.5 MeV/nucleon have been measured with a channel-plate time-of-flight telescope followed by a $\Delta E-E$ gas-ionization chamber. Angular intervals of 10°-15° centered at the grazing angles were covered. The differential cross sections for one-proton transfer with $Q$ values near zero were analyzed using the distorted-wave Born approximation, which can account for the shape of the angular distributions and, to better than a factor of 5, for the absolute cross sections. At $Q$ values more negative than -10 MeV the measured angular distributions begin to deviate from the distorted-wave Born approximation predictions. Substructures were observed in the energy spectra near $Q=-25\mathrm{}$ MeV. A model for unfolding the effects of particle evaporation from the reaction products is developed. It is shown that, within the limitations of the model, the observed substructures cannot be accounted for by evaporation effects alone but must be present in the primary energy spectra. Finally the optimum $Q$ values are analyzed with a one-body dissipation model. The model is reasonably successful if the concept of a local Fermi momentum is introduced.

NUCLEAR REACTIONS Heavy ions ${}_{}{}^{58,64}{}_{}{}^{}\mathrm{Ni}$, ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}({}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}, X)$, $E=320, 460$ MeV; measured $\sigma (Z, A, Q, \theta )$. Substructures in energy spectra, DWBA analysis, evaporation analysis, $Q_{\mathrm{opt}}$ values, transfer-induced energy loss.

It is shown that a spin-orbit potential in heavy ion scattering damps a pronounced oscillation of angular distributions of the backward angle anomaly. The angular distributions with the damped oscillation at back angles in ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$ + ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ scattering are analyzed with a parity dependent optical model by introducing a spin-orbit potential, and fairly good agreement with the data is obtained.

Characteristic resonancelike peaks recently observed in the angle-integrated inelastic cross sections for the ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$-${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ system are understood in terms of the Landau-Zener excitation mechanism at energy level crossings. Angle-integrated inelastic cross sections estimated with the Landau-Zener formula show a series of resonancelike peaks as a function of incident energy, of which is associated with a grazing angular momentum of the relative motion between nuclei. Simple expressions are given for resonance energies and "widths" of new "resonances." This resonance mechanism is a new one, which has not been known in nuclear reactions nor in atomic collisions, although it is based on the well-known Landau-Zener promotion mechanism.

NUCLEAR REACTIONS ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$-${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ inelastic scattering. New Heavy-ion resonance mechanism. Nuclear Landau-Zener excitation mechanism at level crossings. Molecular single-particle effects.

Branching ratios in heavy ion reactions can be quantitatively predicted using the procedure of maximal entropy subject to the constraints that determine the energy distribution. Including the two constraints required to quantitatively determine the energy distribution accounts very well for the branching fractions for all the reactions examined. The branching ratio amongst two ejectiles is given as the ratio of two nuclear partition functions. Including only the single dominant constraint on the energy distribution provides a near quantitative description of the branching ratios. In this latter case, the branching fractions can be computed directly from the optimal $Q$ value. The exact procedure for doing so is described. An approximation to the order of magnitude of the branching fraction into a given exit channel is $\ln P=\beta (Q_{\mathrm{gg}}-〈Q〉)$, where $\beta$ is the temperature of the residual nucleus, $Q_{\mathrm{gg}}$ is the ground-state to ground-state $Q$ value, and $〈Q〉$ is the mean value. In general, both $\beta$ and $〈Q〉$ differ for different exit channels, less so, however, within a given family of isotopes.

NUCLEAR REACTIONS Heavy ions, ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}({}_{}{}^{16}{}_{}{}^{}\mathrm{O}, X)$, $X={}_{}{}^{9,10}{}_{}{}^{}\mathrm{Be}, {}_{}{}^{11-13}{}_{}{}^{}\mathrm{B}, {}_{}{}^{12-15}{}_{}{}^{}\mathrm{C}, {}_{}{}^{15-17}{}_{}{}^{}\mathrm{N}, {}_{}{}^{18,19}{}_{}{}^{}\mathrm{O}$, $E=105\mathrm{}$ MeV at $\theta =70\mathrm{}°$, $X={}_{}{}^{10}{}_{}{}^{}\mathrm{Be}, {}_{}{}^{11}{}_{}{}^{}\mathrm{B}, {}_{}{}^{12-14}{}_{}{}^{}\mathrm{C}, {}_{}{}^{15}{}_{}{}^{}\mathrm{N}$, $E=105\mathrm{}$ MeV at $\theta =50\mathrm{}°, 60°$, $E=125\mathrm{}$ MeV at $\theta =50\mathrm{}°, 60°$. ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}({}_{}{}^{15}{}_{}{}^{}\mathrm{N}, X)$, $X={}_{}{}^{9,10}{}_{}{}^{}\mathrm{Be}, {}_{}{}^{11-13}{}_{}{}^{}\mathrm{B}, {}_{}{}^{12-15}{}_{}{}^{}\mathrm{C}$, $E=86\mathrm{}$ MeV at $\theta =60\mathrm{}°$, $X={}_{}{}^{9-11}{}_{}{}^{}\mathrm{Be}, {}_{}{}^{11-13}{}_{}{}^{}\mathrm{B}, {}_{}{}^{12-15}{}_{}{}^{}\mathrm{C}$, $E=95\mathrm{}$ MeV at $\theta =70\mathrm{}°$. ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}({}_{}{}^{35}{}_{}{}^{}\mathrm{Cl}, X)$, $X={}_{}{}^{30,31}{}_{}{}^{}\mathrm{Si}, {}_{}{}^{31-33}{}_{}{}^{}\mathrm{P}, {}_{}{}^{33-35}{}_{}{}^{}\mathrm{S}, {}_{}{}^{36,37}{}_{}{}^{}\mathrm{Cl}$, $E=205\mathrm{}$ MeV at $\theta =70\mathrm{}°$. ${}_{}{}^{53}{}_{}{}^{}\mathrm{Cr}({}_{}{}^{14}{}_{}{}^{}\mathrm{N}, X)$, $X={}_{}{}^{6,7}{}_{}{}^{}\mathrm{Li}, {}_{}{}^{7,9,10}{}_{}{}^{}\mathrm{Be}, {}_{}{}^{10-12}{}_{}{}^{}\mathrm{B}, {}_{}{}^{12,13}{}_{}{}^{}\mathrm{C}$, $E=90\mathrm{}$ MeV at $\theta =16\mathrm{}°$. Branching fractions and energy distribution of ejectiles. Maximal entropy subject to constraints. Nuclear partition functions.

In this work, we present a theory involving bound states embedded in the continuum in order to explain the observed structures in heavy ion fusion data. As opposed to the continuum-continuum coupling considered in the standard coupled channel calculations, we examine here the effects of interaction of bound states among themselves as well as coupling of the continuum channels with these interacting bound states. By making reasonable approximations within the context of bound states embedded in the continuum, we show that the $S$ matrix for each partial wave can be expressed as a sum of a smooth background term and a resonance term. For the case of a single bound state only, the resonant part of the $S$ matrix is shown to reduce to the Breit-Wigner form. The background part of the $S$ matrix is calculated by using a parabolic barrier in the presence of the Coulomb interaction. The theory is then applied to analyze the fusion excitation functions for the reactions ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$+${}_{}{}^{28,29,30}{}_{}{}^{}\mathrm{Si}$ and is found to account for the structures in the data quite well.

NUCLEAR REACTIONS Heavy ion fusion; coupled channel calculation; bound states embedded in the continua; resonant structures; application to ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$+${}_{}{}^{28,29,30}{}_{}{}^{}\mathrm{Si}$ systems.

High spin states in ${}_{}{}^{97}{}_{}{}^{}\mathrm{Rh}$ and ${}_{}{}^{103}{}_{}{}^{}\mathrm{Rh}$ have been studied via the ${}_{}{}^{94,100}{}_{}{}^{}\mathrm{Mo}({}_{}{}^6{}_{}{}^{}\mathrm{Li}, 3\mathrm{n}\gamma )$ reaction using inbeam gamma ray spectroscopy techniques. Two cascades based on the ${\mathrm{½}}^{-}$ ground state and the lowest ${\frac{9}{2}}^{+}$ state are attributed to ${}_{}{}^{103}{}_{}{}^{}\mathrm{Rh}$. Two cascades based on a proposed ${\frac{13}{2}}^{+}$ level are attributed to ${}_{}{}^{97}{}_{}{}^{}\mathrm{Rh}$. Excitation function and angular distribution measurements are used to assign spin values to many of the levels.

NUCLEAR REACTIONS ${}_{}{}^{94,100}{}_{}{}^{}\mathrm{Mo}({}_{}{}^6{}_{}{}^{}\mathrm{Li}, 3\mathrm{n}\gamma ){}_{}{}^{97,103}{}_{}{}^{}\mathrm{Rh}$, $E=22-34\mathrm{}$ MeV. Measured $E_{\gamma }$, $\gamma -\gamma$ coincidences, $\gamma$-ray angular distributions. ${}_{}{}^{97}{}_{}{}^{}\mathrm{Rh}$, ${}_{}{}^{103}{}_{}{}^{}\mathrm{Rh}$ deduced levels, $J^{\pi }$; enriched targets, Ge(Li) detectors.

Deexcitation $\gamma$ rays of ${}_{}{}^{30}{}_{}{}^{}\mathrm{Al}$ following the ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$(${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$,pn)${}_{}{}^{30}{}_{}{}^{}\mathrm{Al}$ fusion-evaporation reaction have been observed in singles, in coincidence with the evaporated protons, and in coincidence with other $\gamma$ rays in cascade. Gamma-ray yield curves were measured over the ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ beam energy range 15-35 MeV. Angular distributions of $\gamma$ rays observed in coincidence with protons at 0° were measured for four transitions. Limits on level lifetimes were determined, and no evidence for a long-lived isomeric transition was found. Excitation energies deduced are, in keV: 0, 243.90(8), 687.53(12), 991.0(9), 1118.7(7), and 1245.6(8). Corresponding spins and parities are $3^{+}$, ${\mathrm{}(1,2)\mathrm{}}^{\pm }$, $1^{+}$, ${\mathrm{}(2,3,4)\mathrm{}}^{\pm }$, ${\mathrm{}(1,2,3)\mathrm{}}^{\pm }$, and ${\mathrm{}\left(4\right)\mathrm{}}^{\pm }$, respectively. The results are compared to recent shell model calculations.

NUCLEAR REACTIONS ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}({}_{}{}^{18}{}_{}{}^{}\mathrm{O}, \mathrm{pn}\gamma ){}_{}{}^{30}{}_{}{}^{}\mathrm{Al}$, $E\left({}_{}{}^{18}{}_{}{}^{}\mathrm{O}\right)=15-35\mathrm{}$ MeV; measured $I_{\gamma }(E, \theta )$, $E_{\gamma }$; $\mathrm{p}\gamma$ coin; $\gamma \gamma$ coin; deduced decay scheme, limits on $\tau$, probable $J$.

Intranuclear cascade calculations and fluid dynamical predictions of the kinetic energy flow are compared for collisions of ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ + ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ + ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$. The aspect ratio, $R_{13}$, as obtained from the global analysis, is independent of the bombarding energy for the intranuclear cascade model. Fluid dynamics, on the other hand, predicts a dramatic increase of $R_{13}$ at medium energies $E_{\mathrm{lab}}\lesssim 200$ MeV/nucleon. In fact, $R_{13}\left(E_{\mathrm{lab}}\right)$ directly reflects the incompressibility of the nuclear matter and can be used to extract the nuclear equation of stat at high densities. Distortions of the flow tensor due to few nucleon scattering are analyzed. Possible procedures to remove this background from experimental data are discussed.

The NN scattering Bethe-Salpeter equation is solved for $T=1\mathrm{}$ partial wave amplitudes up to 1 GeV lab energy. Coupling to $\mathrm{N}\Delta$ intermediate states is included by $\pi$ and $\rho$ exchange, while NN ↔ NN interactions are due to combined $\pi$, $\rho$, $\eta$, $\epsilon$, $\delta$, and $\omega$ mesons. Inclusion of $\rho$ exchange improves agreement with phase shift analysis in a systematic way.

NUCLEAR REACTIONS Bethe-Salpeter equation, coupled NN-$\mathrm{N}\Delta$ scattering, $\rho$ exchange, NN $T=1\mathrm{}$ phase shifts.