Accession Number : AD0613439

Title :   ISOTOPE SHIFT IN THE ARC SPECTRUM OF NICKEL,

Corporate Author : WISCONSIN UNIV MADISON

Personal Author(s) : Schroeder,Daniel J. ; Mack,J. E.

Report Date : 19 SEP 1960

Pagination or Media Count : 6

Abstract : The isotope shift in 31 spectral lines in the nickel arc spectrum has been determined by the use of a FabryPerot interferometer. The normal mass shifts were calculated (=+0.0251/cm between Ni58 and Ni64) and substracted from the observed isotope shifts. The differences were attributed to the specific mass and field effects. The relative shifts of levels of four configurations were deduced from the observed line shifts, these being the 'complex' configurations 3d84s2 and 3d84s4p and the two-electron configurations 3d94s and 3d94p. It was shown that the shifts due to the specific mass effect are a significant part of the observed shifts. Perturbations due to interconfigurations interactions were postulated to explain some of the observed shifts. The isotope shift to be expected between Ni58 and Ni64 on the basis of field effect calculations is about -0.021/cm for a single 4s electron, while the shifts observed are as large as +0.1901/cm. A large fraction of this shift must therefore be attributed to the specific mass effect. By noting the deviations of the relative shifts between adjacent pairs of even isotopes from those predicted by mass effect theory, it was possible to deduce the relative field effect. Within the experimental error the level shift of the Ni61 relative to the neighboring even isotopes is such that there is no odd-even staggering of the levels. (Author)

Descriptors :   (*NICKEL, ISOTOPES), (*ISOTOPES, NUCLEAR RADIATION SPECTROSCOPY), NUCLEAR SHELL MODELS, PERTURBATION THEORY, ELECTRIC FIELDS, NUCLEAR ENERGY LEVELS, MASS NUMBER

Distribution Statement : APPROVED FOR PUBLIC RELEASE