2020 Impact factor 3.043
Hadrons and Nuclei
Eur. Phys. J. A 2, 173-177

Direct mass measurements of A=80 isobars

S. Issmer1 - M. Fruneau2 - J.A. Pinston2 - M. Asghar2 - D. Barnéoud2 - J. Genevey2 - Th. Kerscher1 - K.E.G. Löbner1

1 Sektion Physik, Universität München, D-85748 Garching, Germany
2 Institut des Sciences Nucléaires, Université Joseph Fourier, CNRS-IN2P3, F-38026 Grenoble Cedex, France

Received: 22 Juli 1997 / Revised version: 3 February 1998 Communicated by P. Armbruster

Direct mass measurements of A=80 isobars were performed using the second cyclotron of SARA (Système Accélérateur Rhône-Alpes) of the ISN (Institut des Sciences Nucléaires) in Grenoble as a time-of-flight mass spectrometer. Using the 300 MeV $\ ^{58}$Ni +$\ ^{27}$Al reaction, the isobars $^{\rm 80}$Rb, $^{\rm 80}$Sr, $^{\rm 80}$Y, and $^{\rm 80}$Zr (only one event!) were measured. For $^{\rm 80}$Y we found a mass value of 79.934320(180) u, corresponding to a decay energy Q ($^{\rm 80}$Y $\rightarrow$ $^{\rm 80}$Sr) of $(9120 \pm 170)$ keV. Comparing this value to the former experiments of Lister et al. and Della Negra et al. results in a difference of about 2.2 MeV. However, it does agree with the recommended value of Audi and Wapstra, which is derived from systematic trends. For $^{\rm 80}$Zr the single event was identified with a probability of 0.999975 and a mass value of 79.940400(1600) u could be deduced from our experiment.

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