[en] We predict a rotational shape isomeric band in ³²S, and propose as 0⁺, 2⁺, 4⁺ candidates the already known levels at 8.507, 9.065 and 10.276 MeV. (orig.)

[en] The impact parameter (b) dependence of the K-shell excitation probabilites (Psub(K)(b)) in the Ar on Ar collision system at 4.5, 8, 12 and 20 MeV impact energy have been measured over a wide b range (from the kinematic peak to far outside the adiabatic peak) for different projectile charge states. In agreement with the data of Lutz et al. and Nolte et al. a very strong increase of Psub(K)(b) towards very small b values (corresponding to scattering angles up to 40sup(o)) has been observed. From the measured b and projectile charge state dependences it has been derived for the systems investigated here the 2pπ-2psigma rotational coupling mechanism gives the dominant contribution to the K-shell excitation as well at the very small b (kinematic peak regime) as at the very large b (adiabatic peak regime). The analysis of the data shows that in disagreement with the general assumption of a b independent 2pπ vacancy probability P₂sub(p)sub(π), the probability P₂sub(p)sub(π) increases towards smaller b. At the high projectile energy the data confirm the results of Nolte et al. of large dynamically produced probability P₂sub(p)sub(π)sup(d) and of strong contributions of direct 2psigma and 1ssigma excitation to the measured Psub(K)(b) at small impact parameters. (orig.)

No abstract available

[en] A high resoltuion electron impact threshold spectrocscopy technique was used to examine the excitation of Cl₂ in the 2-14 eV region. This study complements previous photon absorption and emission measurements, because it is capable of detecting transitions which are optically forbidden. In the region up to 7.5 eV, broad dissociative structures are correlated with optically active valence states, although relative intensities in the threshold spectrum differ considerably and indicate a substantial contribution from the optically forbidden transition. At 7.46 eV a series of 5 equidistant sharp peaks is detected and intepreted as arising from the ²PIsub(g) Feshback resonance, which differs from the ground state positive ion Cl₂⁺ by a pair of Rydberg electrons: (4ssigma)². The decay channels responsible for the appearance of the resonance in a threshold spectrum are discussed and it is suggested that they include several valence states of the (2431) and (2341) configurations, whose potential energy curves cross the Cl₂^-, ²PIsub(g) curve in the region of energy at which the resonance state is formed. At higher incident electron energies and up to ionisation. Rydberg states predominate, starting with (2430) 4s ³sup(,)¹PIsub(g) states detected for the first time. The absence of broad peaks above 8 eV and the irregular appearance of Rydberg bands is consistent with the strong Rydberg-valence configuration mixing proposed by Peyerimhoff and Buenker. Where our resolution permits comparison, good general agreement is found with recent synchroton radiation absorption measurements of optically allowed transitions. (orig.)

[en] ν⁺-ray endpoint energies for mass-separated samples of neutron deficient Rare-Earth isotopes have been measured using intrinsic germanium detector. Qsub(EC) values have been obtained and new isomeric states have been identified for the first time. (orig.)

[en] A perturbative semiclassical approximation for the elastic s-matrix is used to derive simple and accurate formulae describing the effects of a nuclear quadrupole deformation on the elastic scattering of aligned nuclei. Expressions are derived for the second rank tensor components of the analysing power, the ratios of which turn out to be simple trigonometric functions of the scattering angle in agreement with experimental observations. The approximations are discussed in some detail and higher order corrections are derived. In an appendix we derive a semiclassical first-order perturbation formula describing the effect of a non-central complex perturbation in the presence of a non-perturbatively treated central term. Our formula is in agreement with some earlier published formulae which fail to treat the real part of the perturbation correctly. (orig.)

[en] ¹⁰²In, [T(1/2) = (24 +- 4)s], has been identified for the first time using an on-line mass isotopic separator operating on nuclear reactions induced by heavy ions. Gamma-rays observed both in ¹⁰²In → ¹⁰²Cd decay and in-beam measurements allow to build a partial level scheme for ¹⁰²Cd. Systematics of the two first excited states of even cadmium isotopes shows the special behaviour of the lightest one. (orig.)

[en] Spectroscopical investigations of ⁸⁹Br and ⁹⁰Br have been performed, utilizing the formation of the molecular ion AlBr⁺ in the ion-source of an isotope separator on-line a reactor. Detailed level schemes have been constructed for ⁸⁹Kr and ⁹⁰Kr, and the β-strength function of ⁸⁹Br and ⁹⁰Br below the neutron binding energy is presented. The total decay energy of 89,90Br, as well as of ⁸⁹Kr, have been measured by means of β γ-coincidences, and the population of excited states in ⁸⁹Kr via ⁹⁰Br delayed neutrons has been deduced. (orig.)

[en] A fully quantum-mechanical analysis is presented of the process in which an incident proton excites both a nuclear resonance and, by electron emission, also a hole in the K-shell which then decays by X-ray emission. The ratio of the intensities of the X-rays emitted before and after compound-nucleus decay is calculated (a) for the case of an isolated nuclear resonance, and (b) for strongly overlapping resonances. We show that in both cases the measured quantity is a branching ratio. The influence of the energy-resolution of the detectors, of energy spread of the incident beam, and of the structure of the wave packets describing the individual particles in the incident beam is discussed. (orig.)

[en] We apply correlation function techniques to the calculation of nuclear friction within the framework of a linear response theory. We make use of the fluctuation dissipation theorem to relate the response function to the correlation function which is evaluated by exploiting projection operator techniques. We go beyond the one-body dissipation approximation in the sense that we have taken into account the decay of particle-hole excitations into more complicated configurations. A rather simple formula for the frequency and temperature dependence of the friction coefficient is derived which we have applied to the high energy fission of ²³⁸U. The friction coefficients for deformations around the first and second minima of the fission barrier have been calculated using this approach. (orig.)