J. Davidson

High-spin states in sup 166 Lu

High-spin states belonging to {sup 166}Lu have been studied through the {sup 159}Tb({sup 12}C,5{ital n}) fusion-evaporation reaction in the energy range {ital E}({sup 12}C)=75--90 MeV. In-beam and activity singles spectra and {gamma}-{gamma}-{ital t} coincidences have been measured. A completely new level scheme is proposed. Each rotational band is interpreted on the basis of coupling scheme systematics. {ital g}-{ital S} crossing frequencies and alignments have been extracted. {ital B}({ital M}1)/{ital B}({ital E}2) reduced transition probability ratios have been calculated using a semiclassical method and compared to the experimental values.

Pseudo-spin flip in doubly decoupled structures and identical bands

Abstract Unfavored components of doubly decoupled bands are reported for the first time. They can be interpreted as having the pseudo-spin flipped relative to the orientation in the favored components, i.e. antialigned with respect to the rotation axis. In addition, the differences in consecutive transition energies along the favored and unfavored sequences are strikingly similar among them up to Iπ = 15+and 14+ respectively. This feature arises from a cancellation of differences in alignments and moments of inertia.

Radiographic Technique for Densitometric Studies Using Heavy Ion Microbeams

Different analytical techniques are typically used to perform multi‐elemental and densitometric analysis by means of particle beams with micrometric space resolution. Usually, those analyses are respectively performed by PIXE and STIM. Traditionally, to characterize the trace element concentrations in a specimen two different experiments are required with differences in setups and types of detectors employed, as well as in the necessary ion current intensities. In this work, we discuss the latest results in the development of a new technique that synthesizes both analyses in just a single one, by means of heavy ion induced x‐ray emission. This technique, implemented for the first time at the Tandar Laboratory, employs a second target in addition to the sample under study. The multi‐elemental information of the specimen is provided by its PIXE signal and its densitometric information is supplied by the PIXE signal of the secondary target, which is placed immediately behind the sample under analysis. These PIXE signals are produced and acquired during the same experiment, allowing the analysis of both features (composition and density) at the same time. The X‐rays originated in the secondary target are attenuated when traversing the specimen in the direction of the detector and consequently a radiographic image of the specimen is obtained. In this case, the characteristic X‐rays of the secondary target act like a monochromatic secondary source. In the present work, a method to estimate the thickness of specimens is introduced and compared with estimations performed by the STIM method.Different analytical techniques are typically used to perform multi‐elemental and densitometric analysis by means of particle beams with micrometric space resolution. Usually, those analyses are respectively performed by PIXE and STIM. Traditionally, to characterize the trace element concentrations in a specimen two different experiments are required with differences in setups and types of detectors employed, as well as in the necessary ion current intensities. In this work, we discuss the latest results in the development of a new technique that synthesizes both analyses in just a single one, by means of heavy ion induced x‐ray emission. This technique, implemented for the first time at the Tandar Laboratory, employs a second target in addition to the sample under study. The multi‐elemental information of the specimen is provided by its PIXE signal and its densitometric information is supplied by the PIXE signal of the secondary target, which is placed immediately behind the sample under analysis. These ...

High-spin states in odd-odd 168Tm

High‐spin states in 168Tm were investigated by means of γ‐ray spectroscopy techniques using the GASP multidetector array. Rotational bands have been established and identified in terms of their configurations.

Doubly decoupled bands in176, 178Re

High spin states in176, 178Re have been studied using in-beam γ and e− spectroscopy techniques through heavy ion induced fusion reactions. A ΔI=2 rotational band of doubly decoupled type has been identified in each isotope.