Nuclear Data Sheets for A = 202

Spectroscopy of the proton drip-line nucleus203Fr

“…Based on the α-particle and conversion-electron yields, a branching ratio of 20(4)% for the α decay of the 1/2 + isomer was obtained. Additionally, a reduced α-emission width of 51 keV was extracted for this decay using the method developed by Rasmussen [44], resulting in a hindrance factor of 1.1 as compared with the ground-state α decay of 202 Rn [45]. This is a sign of a favored α decay between states of equal spin and parity.…”

Combined high-resolution laser spectroscopy and nuclear decay spectroscopy for the study of the low-lying states inFr206,At202, andLynch1, Cocolios2, Billowes3 et al. 2016Phys. Rev. C

“…In the study of the 3 (+) and 7 (+) states in 206 Fr, the α-decay events at 6792 keV are compared to those resulting from the α decay of 206 Rn at 6259 keV [37], whereby 206 Rn is populated from the β decay of 206 Fr. Using beams of 206 Fr separated by CRIS, the beam purity is guaranteed by putting the first laser on resonance with one particular hyperfine transition, thus a single state is delivered to the DSS.…”

High-resolution study of excited0+states in200Hg and202Hg

“…Three of these 0 + states were known as 0 + states previously [17]. The state at 2599 keV has not been reported before and shows the typical L = 0 transfer signature with R(5/17.5) = 4.25(39).…”

“…Out of the five states, only the state at 2127-keV excitation energy was observed before and was assigned spin J = (2 + ) [17]. For firm assignments, more statistics is needed so we can only assign tentative spin J = (0 + ) for these states, being well aware that these tentative assignments might simply be caused by the low statistics for these states.…”

“…For each nucleus, the experimental runs were normalized to the integrated beam current measured in a Faraday cup behind the target. The measured triton spectra were calibrated using well-known level energies of 200 Hg and 202 Hg compiled in the Nuclear Data Sheets [16,17]. Contaminants stemming from target impurities were identified by using the known Q values of the corresponding (p, t) transfer reaction [18].…”