Eur. Phys. J. A 11, 257-261 (2001)
Isomeric state of 80Y and its role in the astrophysical rp-process
Yu.N. Novikov1, 2, H. Schatz3, P. Dendooven4, R. Béraud5, Ch. Miehé6, A.V. Popov1, D.M. Seliverstov1, G.K. Vorobjev2, P. Baumann6, M.J.G. Borge7, G. Canchel5, Ph. Desagne6, A. Emsallem5, W. Huang4, J. Huikari4, A. Jokinen4, A. Knipper6, V. Kolhinen4, A. Nieminen4, M. Oinonen8, H. Penttilä4, K. Peräjärvi4, I. Piqueras6, 7, S. Rinta-Antila4, J. Szerypo4, Y. Wang4 and J. Äystö81 St. Petersburg Nuclear Physics Institute, Gatchina, 188350, Russia
2 St. Petersburg State University, St. Petersburg, 198904, Russia
3 Michigan State University, East Lansing, MI 48824, USA
4 Department of Physics, University of Jyväskylä, Jyväskylä, 40351, Finland
5 Institut de Physique Nucléaire de Lyon, CNRS-IN2P3 and Université Claude Bernard, 69622 Villeurbanne Cedex, France
6 Institut de Recherches Subatomiques, UMR7500, CNRS-IN2P3 and Université Louis Pasteur, BP28, 67037 Strasbourg Cedex, France
7 Instituto de Estructura de la Materia, 28006 Madrid, Spain
8 ISOLDE, CERN, CH-1211, Geneva 23, Switzerland
novikov@pnpi.spb.ru
(Received: 14 March 2001 / Revised version: 3 July 2001 Communicated by C. Signorini)
Abstract
A careful investigation of the isomeric transition
of the long-lived
state at 228.5 keV excitation energy in 80Y has been done. The HIGISOL facility at the
Jyväskylä isochronous cyclotron has been used.
We used the electron magnetic
transporter to prepare an appropriate source and to measure the
electron spectra in clean background conditions. The measured
internal conversion coefficient
allows
unambiguous 1- identification for the 228.5 keV first excited isomeric
state in 80Y.
With a "bare" half-life of
s found in this work, this state is
strongly populated in the rp-process during X-ray bursts and has therefore
to be taken into account in X-ray burst model calculations. However,
because of the similarity of the
-decay half-lives of isomeric and
ground states, we find a maximum reduction in the effective
-decay lifetime
of 80Y of only
% . Our results
pave the way for a future investigation of the impact of the isomeric state
on the "effective" 80Y proton capture rate.
21.10.Tg - Lifetimes.
23.20.Nx - Internal conversion and extranuclear effects.
27.50.+e -

© Società Italiana di Fisica, Springer-Verlag 2001