Direct mass measurements of A=80 isobars were performed using the
second cyclotron of SARA (Système Accéléra teur Rhône-Alpes) of the
ISN (Institut des Sciences Nucléaires) in Grenoble as a time-of-flight mass
Using the 300 MeV 58Ni27Al reaction, the isobars
80Rb, 80Sr, 80Y, and 80Zr (only one event!)
For 80Y we found a mass value of 79.934320(180) u,
corresponding to a decay energy Q (80Y →80Sr) of
(9120±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 80Zr 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