On the Level Scheme of ²¹⁴Bi and the α Decay of ²¹⁸At

Abstract

A decay scheme of 214 Pb has been developed on the basis of gamma-gamma coincidence and summing coincidence measurements. New levels are proposed at 62.69,104.2 and 377.04 keV.The ground state, the 62.69 and the 102.4 levels of 214 Bi are fed in the alpha decay of 218 At.

Fine structure in the α decay of At218

“…This value is closest to the calculated value α tot,calc (M1) = 11.99 (17) and much lower than α tot,calc (E 2) = 127.5(18) [24], confirming the near-pure M1 assignment of previous studies [11][12][13][14][15][16].…”

“…1(b) and 1(c). The 63 keV level was originally inferred from high-statistics γ -γ coincidence data and assigned a most probable J π = (3 − ) [15,16]. The nonobservation of this γ decay was explained in Ref.…”

“…In Ref. [15], the 6694 and 6655 keV α decays were assigned to feed directly to the 63 keV level and a 102 keV excited states in 214 Bi, respectively, based on their difference in Q α with the 6756 keV decay cited in Ref. [9].…”

“…Published information on the daughter nucleus 214 Bi comes from a series of β-decay studies of 214 Pb → 214 Bi [11][12][13][14][15][16] and 214 Bi → 214 Po [17]. Together, these studies firmly established J π ( 214 Bi g ) = 1 − , with a most probable π 1h 9/2 ⊗ ν2g 9/2 configuration.…”

“…Furthermore and of importance to the present work, two low-lying, negative-parity states at excitation energies of 53 and 63 keV were deduced. These states were suggested to be members of the same π 1h 9/2 ⊗ ν2g 9/2 multiplet, with most probable spins and parities of J π = (2) − and (3 − ), respectively [15,16].…”