(EC + β+) decay of 133Sm and 1.1 s isomer of 133Pr

Abstract

The very neutron-deficient isotope 133 Sm was produced by irradiation of an enriched target of 96 Ru with 40 Ca and studied by using a helium-jet fast tape transport system in combination with X-γ and γ-γ coincidence measurements. A simple (EC + β + ) decay scheme of 133 Sm was proposed for the first time. As a by-product 133 Pr was produced simultaneously because of the 98-102 Ru content of the ruthenium target. The half-life of a 11/2 − low-lying isomeric state in 133 Pr was measured to be 1.1 ± 0.2 s. PACS. 23.40.-s Beta decay; double beta decay; electron and muon capture -21.10.Tg Lifetimes -27.60.+j 90 ≤ A ≤ 149

Reaching the limits of nuclear stability

“…For example, table 4 lists the proton separation energies for neutron-deficient holmium isotopes [105]. The separation energies for [142][143][144][145][146] Ho have to be extracted from mass measurements and extrapolations with uncertainties of hundreds of keV. In contrast, the direct observation of the proton emission of 141 Ho [152] and 140 Ho [139] allows an accurate determination of the separation energy.…”