New measurement of (7)Be half-life in different metallic environments

(7)Be decays via electron capture and therefore its half-life is expected to depend on the electron density at the nucleus. We measured the (7)Be half-life in palladium, tungsten, zirconium and tantalum metals, in order to investigate the influence of the quasi-free electrons in metals on the probability of electron capture. The (7)Be samples were obtained implanting a 4.85 MeV pure radioactive (7)Be ion beam. The (7)Be half-life was determined measuring the 478 keV gamma decay following the electron capture by means of HPGe detectors. In order to reduce systematic errors, we planned to perform independent measurements in three different laboratories: Naples (Italy), Bochum (Germany) and Debrecen (Hungary). On the basis of the first results, we do not find a (7)Be half-life change within the experimental errors of 0.4%. RI Fulop, Zsolt/B-2262-200