The α decays of naturally occurring platinum isotopes, which are accompanied by the emission of γ quanta, have been searched for deep underground (3600 m water equivalent) at the Gran Sasso National Laboratories of the INFN (Italy). A sample of Pt with a mass of 42.5 g and a natural isotopic composition has been measured with a low background HP Ge detector (468 cm3) during 1815 h. The α decay of 190Pt to the first excited level of 186Os (Jπ=2+, Eexc=137.2 keV) has been observed for the first time, with the half-life determined as T1/2=2.6-0.3+0.4(stat.)±0.6(syst.)×1014 yr. The T1/2 limits for the α decays of other Pt isotopes have been determined at the level of T1/2≃1016–1020 yr. These limits have been set for the first time or they are better than those known from earlier experiments.
Belli, P., Bernabei, R., Cappella, F., Cerulli, R., Danevich, F., Incicchitti, A., et al. (2011). First observation of α decay of 190Pt to the first excited level (E_exc = 137.2 keV) of 186Os. PHYSICAL REVIEW. C, NUCLEAR PHYSICS, 83, 034603-034609 [10.1103/PhysRevC.83.034603].
First observation of α decay of 190Pt to the first excited level (E_exc = 137.2 keV) of 186Os
BERNABEI, RITA;
2011-01-01
Abstract
The α decays of naturally occurring platinum isotopes, which are accompanied by the emission of γ quanta, have been searched for deep underground (3600 m water equivalent) at the Gran Sasso National Laboratories of the INFN (Italy). A sample of Pt with a mass of 42.5 g and a natural isotopic composition has been measured with a low background HP Ge detector (468 cm3) during 1815 h. The α decay of 190Pt to the first excited level of 186Os (Jπ=2+, Eexc=137.2 keV) has been observed for the first time, with the half-life determined as T1/2=2.6-0.3+0.4(stat.)±0.6(syst.)×1014 yr. The T1/2 limits for the α decays of other Pt isotopes have been determined at the level of T1/2≃1016–1020 yr. These limits have been set for the first time or they are better than those known from earlier experiments.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
