216PO    220RN A DECAY                 1977Ku15                  26NDS    202603
216PO  H TYP=FUL$AUT=C. Morse$CIT=NDS 209, 409 (2026)$CUT=5-Aug-2025$
216PO c  1977Ku15: {+220}Rn activity from decay chain of {+232}U; E|g, I|g
216PO2c  measured;  Ge(Li) detectors.
216PO c  1989Po03: {+220}Rn activity from decay chain of {+228}Th; measured
216PO2c  E|g, I|g, |a|g-coin. |g(|q); POLYTESSA array, 24 Compton suppressed
216PO3c  Ge(Li) detectors.
216PO c  2024Pi01: {+220}Rn produced from {+224}Ra source at NIST and NPL.
216PO2c  Measured absolute I{-|g} using HPGe detectors, deduced absolute
216PO3c  I{-|a}.
216PO cL J$From Adopted Levels
216PO cL SEQ(A)$Yrast sequence
216PO cA HF$The nuclear radius parameter r{-0}({+216}Po)=1.55513 {I25} is
216PO2cA deduced from assumed HF=1.0 for the ground-state to ground-state
216PO3cA alpha decay branch
216PO cA IA$From 2024Pi01, calculated from absolute intensity of the 549-keV
216PO2cA |g ray.
216PO dA HF$Hindrance Factor is calculated by AlphaHF (version 16-Dec-2025)
216PO DG CC$FROM BrIcc v2.3e (17-Jun-2020) 2008Ki07, "Frozen Orbitals" appr.
220RN  P 0            0+                56.0 S    3              6404.74  10
220RN cP T$Unweighted average of 56.3 s {I2} (1961Ro14), 56.6 s {I8}
220RN2cP (1961Ro14), 55.30 s {I15} (1963Gi17), and 55.61 s {I4} (1966Hu20).
220RN3cP Others: |?60 s (1900Ru01), 51.2 s (1904Le01), 54 s (1905Br01), 53.3 s
220RN4cP (quoted in 1963Gi17 from a 1905 publication), 54.3 s (1912Le01),
220RN5cP 54.530 s {I41} (1914Pe01), 54.50 s {I3} (quoted in 1963Gi17 from a
220RN6cP 1917 publication), 51.5 s {I10} (1955Sc81, but appears discrepant),
220RN7cP 61 s {I+10-8} (2003Da24), 64 s {I+19-12} (2012Be14), 58 s {I4}
220RN8cP (2018Ba44), 56.5 s {I110} (2025Gu12).
220RN cP T$Despite the relatively large number of {+220}Rn half-life
220RN2cP measurements, most are discrepant with one another.  Measurements
220RN3cP from the early 20{+th} century generally did not report
220RN4cP uncertainties, while values from the mid-twentieth century report
220RN5cP uncertainties which are generally smaller than the scatter in the
220RN6cP data points and may be slightly larger than prior reports.  The few
220RN7cP values published in the 21{+st} century report much larger
220RN8cP uncertainties, but with a possible bias towards even longer
220RN9cP half-lives.  The unweighted average of the mid-twentieth century
220RNacP values has been taken as the half-life.
220RN cP QP$From 2021Wa16
216PO  N 1.0                    1.0
216PO PN                                                                     4
216PO  L 0            0+                                                    A
216PO  A 6288.08   1099.8766 351.0
216PO cA E$from 1991Ry01 based on measurement by 1971Gr17
216PO  L 549.73    5  2+                                                    A
216PO cL E$from E|g
216PO  G 549.73    5  0.1200 34 (E2)                    0.02574
216POX G %IG=0.1200 34
216POS G KC=0.01826 26$LC=0.00561 8$MC=0.001399 20$NC=0.000359 5$OC=7.21E-5 10$
216POS G PC=8.05E-6 11
216PO cG E$from 1977Ku15
216PO cG RI$Weighted average of 0.1206 {I45} and 0.1193 {I52} reported in
216PO2cG 2024Pi01.  Other: 0.114 {I17} recommended by 1986LoZT based on
216PO3cG measurements by 1984Ge07, 1977Ku15
216PO cG M$Q from |a|g(|q) (|a decay of J|p=0+ parent), with A{-2}=1.22 {I71}
216PO2cG and A{-4}=-0.91 {I128} (1989Po03). |p from level scheme.
216PO  A 5747        0.1234  352.92    9
216PO cA E$from 1962Wa28; other: 5.75 MeV (1989Po03)