M. E. Debray

Heavy ion induced X-ray emission work at the TANDAR laboratory in Buenos Aires

Abstract The PIXE technique, using heavy ions beams, has been implemented at the TANDAR tandem facility in Buenos Aires. Mainly 16O beams in the bombarding energy range E = 30−50 MeV have been used and a systematic measurement of X-ray production cross sections has been performed. The technique has been applied to a variety of subjects, including environmental, biomedical and industrial problems.

K X-ray production induced by 12C on several elements

Abstract K X-ray production cross sections, photopeak energy shifts and I(Kβ)/I(Kα) intensity ratios are measured for 12C projectiles, in the 14–50 MeV bombarding energy range, on several elements (Al, Si, S, Cl, K, Ca, Ti, Cr, Fe and Cu), using high resolution Si(Li) X-ray spectroscopy. A comparison is made with calculated ECPSSR cross-section values corrected by multiple ionization of K, L and M target subshells and electron capture into the partially empty K-shell of the projectile. The main application for these measurements is multielement trace analysis through particle induced X-ray emission.

PIXE analysis of heavy water from a nuclear power plant

Abstract The PIXE technique, using heavy ion beams, has been applied to the analysis of heavy water samples from the moderator of a power reactor. Different samples have been measured, coming from the moderator itself and from unused heavy water. Both types of samples contain Fe, Cu and Zn in variable concentrations. In those taken from the moderator, Tc and Xe were also detected. The PIXE technique, used with preconcentrated water, leads to a very high sensitivity below the parts-per-billion limit.

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.

High spin states in48Cr

The ground state band of48Cr has been extended to high spins through the reaction24Mg(32S,2α). The assignment of the transitions was based onγ-γ-γ andγ-γ-particle(E, ΔE) - coincidences. The data confirm theoretical predictions based on fullfp spherical shell model calculations.

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.

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.