The decay of 203Hg, 203Pb and 201Pb

Abstract

Synopsis 203Hg and 203Pb have been studied with scintillation- and β-ray spectrometers. The transitions to the 203Tl ground states are absent in both; both decay to a 279 ± 1 keV state in 203Tl(αK = 0.141 ± 0.015, K/L = 3.30 ± 0.10, L/(M + N) = 3.45 ± 0.3; E2 + M1). In 203Pb 5.1% of the nuclei decay to a 679 ± 2 keV state in 203Tl, which emits for 4.3% a 400 ± 2 keV γ-ray (αK = 0.118 ± 0.015, K/L = 6.0 ± 0.4, L/(M + N) = 4.5 ± 0.7; E2 + M1) and for 0.8% a 678 ± 3 keV γ-ray (αK = 0.009 ± 0.003, E2). The maximum energy of the 203Hg β-spectrum is 219 ± 10 keV. In 201Pb a 325 keV transition (K/(L + M) = 5 ± 1.5) and a 583 keV transition were found; the halflife was 8.4 ± 1 h.