212AT 216FR A DECAY (71 NS) 1996LI37 20NDS 202009
212AT H TYP=FUL$AUT=K. Auranen and E.A. McCutchan$CIT=NDS 168, 117 (2020)$
212AT2 H CUT=1-Aug-2020$
212AT c 1996Li37: {+216}Fr activity was measured in secular equilibrium with
212AT2c {+224}Pa(T{-1/2}=0.8 s) and {+220}Ac(T{-1/2}=26 ms). {+224}Pa was
212AT3c produced by {+209}Bi({+18}O,3n), E=96 MeV. Measured alpha particles,
212AT4c |g rays, |a|g coin, conversion electrons, |a-ce and |a-|g-ce coin.
212AT5c Detectors not given. However, |a- and |g-ray spectra suggest that
212AT6c Si(Au) surface barrier and germanium detectors, respectively, were
212AT7c used.
212AT cA HF$Using r{-0}({+212}At)=1.5522 {I36}, average of
212AT2cA r{-0}({+214}Rn)=1.5655 {I13}, r{-0}({+212}Rn)=1.5433 {I36},
212AT3cA r{-0}({+212}Po)=1.5658 {I59}, and r{-0}({+210}Po)=1.5340 {I25}
212AT4cA (2020Si16).
212AT cL E$From E|g.
212AT cL J,T$From the Adopted Levels
212AT cG M$From the Adopted Gammas. For cases where values are derived from
212AT2cG this dataset, additional support is given in the comments.
212AT D CC$FROM BrIcc v2.3b (16-Dec-2014) 2008Ki07, "Frozen Orbitals" appr.
216FR P 133.3 1 (3-) 71 NS 5 9174 3
212AT N 10 0.1 LT
212AT cN BR$the |a decay branch is evaluated in 2007Wu02 as %|a > 50 based on
212AT2cN an intensity balance from the |a decay of {+220}Ac. The decay
212AT3cN proceeds by a single allowed unhindered 8933|a transition. Such a
212AT4cN large |a decay branch for this short lived isomer leads to HF < 0.24
212AT5cN which is unphysical. The evaluators adopt a conservative %|a < 10 %,
212AT6cN from the requirement that HF be not smaller than one.
212AT7cN If one considers that HF for the
212AT8cN g.s. to g.s. allowed, unhindered transition is HF=1.7 based on
212AT9cN systematics, this would imply %|a |? 6%.
212AT cN NR$intensities are given in 1996Li37 as normalized to 100 total
212AT2cN decays from both the 1-, 0.70 |ms g.s and the 133-keV, 71 ns isomer
212AT3cN measured in equilibrium with the {+220}Ac parent. Gamma-ray
212AT4cN intensities given here are deduced by evaluators from measured
212AT5cN absolute |a intensities and |g feedings; original values from
212AT6cN 1996Li37 given in the comments.
212AT PN 3
212AT L 0.0 (1-) 0.314 S 3
212AT L 55.0 2 (1-,2-)
212AT cL E$a weak transition at 55 keV is observed in coincidence with the
212AT2cL 8933-keV |a peak, however feeding of the 55-keV level could not be
212AT3cL identified. 1996Li37 suggest a possible 105-keV transition between
212AT4cL the 160-keV level and the 55-keV level to account for the imbalance,
212AT5cL however, this transition is not discernable in |a|g coincidence
212AT6cL spectra.
212AT G 55.0 2 (M1) 13.28
212ATS G LC=10.12 18$MC=2.40 5$NC=0.621 11$OC=0.1330 24$PC=0.0184 4
212AT cG E$a weak transition at 55 keV is observed in coincidence with the
212AT2cG 8933-keV |a peak, however feeding of the 55-keV level could not be
212AT3cG identified.
212AT cG RI$|? 0.03 normalized to 100 total decays from both the 0.70 |ms
212AT2cG g.s and the 133-keV, 71 ns isomer measured in secular equilibrium
212AT3cG with the {+220}Ac parent (1996Li37)
212AT L 160.3 1 (2-)
212AT G 160.3 1 2.4 5 M1 3.16
212ATS G KC=2.56 4$LC=0.457 7$MC=0.1083 16$NC=0.0281 4$OC=0.00601 9$
212ATS G PC=0.000830 12
212AT cG M$I(K| x ray)=3.0 {I5} in |a-K| x ray coin is consistent with M1
212AT2cG multipolarity. Also K| x ray/I|g(160.3|g)=3 {I1} suggests M1.
212AT cG RI$1.0 {I2} normalized to 100 total decays from both the 0.70 |ms
212AT2cG g.s and the 133-keV, 71 ns isomer measured in secular equilibrium
212AT3cG with the {+220}Ac parent (1996Li37)
212AT L 205.3 2 (3-)
212AT G 45.0 1 0.40 1 M1 24.0
212ATS G LC=18.2 3$MC=4.32 7$NC=1.120 18$OC=0.240 4$PC=0.0331 6
212AT cG M$transition-intensity balance at 160-keV level requires |a|?25, thus
212AT2cG the 45-keV |g ray is predominately M1.
212AT cG RI$0.15 {I5} normalized to 100 total decays from both the 0.70
212AT2cG |ms g.s and the 133-keV, 71 ns isomer measured in secular equilibrium
212AT3cG with the {+220}Ac parent (1996Li37)
212AT A 8933 8 100 1 GT
212AT cA $Observed in coincidence with 45.0|g.