Low-lying Excited Levels Research Articles

Stereochemistry and the choice between alternative descriptions of oxidation states

In molecules and complex ions without low-lying excited levels and containing N equivalent ligands, the relative plausibility of changes of the central atom oxidation state by 2 N units is a helpful description.

Low-Lying Excited Levels in200Hg

Low-lying excited levels in 200 Hg were investigated with a Ge(Li) gamma-ray spectrometer and with an internal conversion coefficient spectrometer. The spin and parity 2 + of the 1028.7-keV third excited level were confirmed, based on the internal conversion coefficient and K/L ratio of the transition from this level to the first excited 2 + state. Several new lines were found. A revised decay scheme was proposed. The experimental results showed that the nuclear structure of this nucleus can be understood fairly well with a model of two-proton holes coupled to harmonic surface vibrations.

Energy levels of zirconium isotopes

The energies of seven low-lying excited levels of 90Zr, 91Zr, and 92Zr have been measured to within a few tenths of a keV. A high-intensity bremsstrahlung beam from a linear accelerator was used to create the radioactive niobium nuclei, 92Nb, 91Nb, and 90Nb by the (γ, n), (γ,2 n), and (γ,3 n) reactions on 93Nb. After the niobium nuclei decayed to the zirconium isotopes, 92Zr, 91Zr, and 90Zr, the energies of the transition γ-rays from these zirconium isotopes were measured with a high-resolution, lithium-drifted germanium detector and were used to determine the energy levels of the zirconium isotopes. The energy levels determined in this way are, for 90Zr, 2186·3, 2318·8, 3447·6, and 3590·4 keV; for 91Zr, 1205·0 keV; and for 92Zr, 934·3 and 1847·2 keV.

Excitation of low-lying levels of Al27, Cr52, Fe56, and Bi20.9 in the inelastic scattering of 1?4 MeV neutrons

Excitation of low-lying levels of Al27, Cr52, Fe56, and Bi20.9 in the inelastic scattering of 1?4 MeV neutrons

Excitation of low-lying levels in Ca 40 by (p , p') scattering at Ep = 55 MeV

Excitation of low-lying levels in Ca 40 by (p , p') scattering at Ep = 55 MeV

Optical model for cross sections of radiative capture and inelastic neutron scattering

The application of the optical model to the calculation of inelastic scattering with excitation of low-lying levels and radiative capture cross sections is considered. A satisfactory agreement with experiment is obtained.

Intrashell-interaction levels and their excitation by multicharged ions

Abstract On the basis of the shell model of the nucleus one may anticipate the existence of the whole series of hitherto unknown nuclear levels arising from the interaction of nucleons in a given shell. Many of these levels possess angular momenta which strongly differ from those of the ground state, although their energy above the ground state is sufficiently low. The most efficient method of excitation of such levels would seem to be by bombardment of nuclei with multicharge ions. The theory of excitation of low-lying levels by inelastic scattering of complex nuclei is considered. New cases of nuclear isomerism may be produced by low energy E2-transitions between intrashell-interaction levels.

The Absorption Spectra of Europium Ion in Some Hydrated Salts

The absorption spectra of crystalline EuCl3·6H2O, EuBr3·6H2O, and Eu2(SO4)3·8H2O were photographed at various temperatures in the visible and ultraviolet region of the spectra. The salts were found to have low-lying excited levels at about 300 cm-1, 390 cm-1, 938 cm-1, 970 cm-1 and, perhaps, 430 cm-1, which arose from excited electronic, crystal and vibrational frequencies. These levels are discussed in relation to existing theories of specific heat, magnetic susceptibility, etc., of europium.