217RN 221RA A DECAY 1997LI12,2015AH04 18NDS 201802
217RN H TYP=FUL$AUT=E.A. MCCUTCHAN, J. LEE, N. JOVANCEVIC$
217RN2 H CIT=NDS 147, 382 (2018)$CUT=1-DEC-2017$
217RN c 2015Ah04: Parent {+225}Th was produced by |a decay of {+229}U
217RN2c produced via {+229}Th({+4}He,4n) and {+230}Th({+3}He,4n) reactions.
217RN3c The Th targets in milligrams were bombarded with microamp current of
217RN4c {+4}He and {+3}He beams provided by Argonne 152-cm cyclotron. The
217RN5c uranium activity produced in the reactions was chemically separated,
217RN6c followed by mass separation using the Argonne electromagnetic isotope
217RN7c separator. The experiment used both the mass separated as well as
217RN8c non-mass separated sources, the latter for higher statistics, since
217RN9c the activity of mass separated sources was much reduced in the
217RNac separation process. Gamma rays were measured with a LEPs and a
217RNbc coaxial Ge(Li) detector. Measured E|g, I|g
217RN c 1997Li12: 10 g of a Th-Ce alloy were bombarded by a 280-MeV 2 |mA
217RN2c beam of {+3}He at the Orsay Synchrocyclotron. The target constituted
217RN3c the anode of an ion-source arc chamber and was continuously
217RN4c fluorinated by introducing CF{-4} vapor. Using the ISOCELE separator
217RN5c and the selective fluorination method, {+221}Ra was separated as
217RN6c RaF{++}. The resolution of the |a detector was 21 keV. Measured E|a,
217RN7c E|g, |a|g-coin. Deduced levels, J, |p, configuration.
217RN c 1989Ac01: The {+225}Th |a-radioactivity was produced by bombarding a
217RN2c {+226}Ra target with 52 MeV |a-particles from the Bonn cyclotron.
217RN3c |g-rays and conversion-electrons were measured in coincidence with
217RN4c |a-particles, with the beam pulsed on/off with a period of
217RN5c approximately 10 min. Deduced levels, ICC, I|g, |g-multipolarity.
217RN c 1961Ru06: Using a 180|' double-focusing alpha-particle spectrograph
217RN2c and scintillation spectrometers, the alpha and gamma radiations of
217RN3c {+229}U series were investigated. The light-uranium isotopes were
217RN4c produced by bombardment of {+232}Th with the internal helium ion beam
217RN5c of the 184-inch synchrocyclotron. Measured E|a, I|a, E|g, I|g,
217RN6c |a|g-coin. Deduced levels.
217RN c (|a)(|g) coincidences were taken by 1961Ru06, 1989Ac01, 1995Ch74 and
217RN2c 1997Li12, and (|a)(ce) coincidences by 1989Ac01.
217RN c The main decay scheme was first constructed by 1961Ru06, and
217RN2c confirmed by 1989Ac01 and 1997Li12. Additional transitions were
217RN3c observed and placed by 1997Li12 in the decay scheme with additional
217RN4c levels. The decay scheme is presented here as built by 1997Li12.
217RN cG $I(K|a| x ray+K|b| x ray)(Rn)/I(149.2|g)=62 {I8}/100 (1997Li12)
217RN cA E$Except where noted, measurements of 1997Li12 are given. Calibration
217RN2cA energies were not given; therefore, no adjustment for E{-|a}'s has
217RN3cA been made. If the energies were calibrated at E{-|a}(g.s.)=6754, as
217RN4cA measured by 1961Ru06, then they should be increased by 7 keV due to
217RN5cA increase in calibration energies used by 1961Ru06. No uncertainties
217RN6cA were given by 1997Li12. Resolution was 21 keV. Other measurements:
217RN7cA 1951Me10, 1961Ru06. The energies of 1961Ru06 are quoted with an
217RN8cA increased value by 7 keV from their original energies, as recommended
217RN9cA by 1991Ry01.
217RN cA IA$Alpha intensity per 100 alpha decays, measured by 1997Li12, See
217RN2cA also a comment for 6581|a. Uncertainties are assigned by the
217RN3cA evaluators (no uncertainties were given in 1997Li02). Other
217RN4cA measurement: 1961Ru06.
217RN cA HF$r{-0}({+217}Rn)=1.550 {I8}, average of r{-0}({+216}Rn)=1.556 {I6}
217RN2cA and r{-0}({+218}Rn)=1.5446 {I19} (1998Ak04), is used in calculations.
217RN cG E$From 1997Li12, except where noted. Other measurements: 1961Ru06,
217RN2cG 1989Ac01, 2015Ah04. Of the four additional questionable |g's reported
217RN3cG by 1961Ru06, the gammas seen by 1961Ru06 at 219 keV {i10} with I=0.1%,
217RN4cG at 293 keV with I=0.6%, and at 415 {i10} keV with I=0.5%, may be
217RN5cG associated with the 207.9|g, 289.1|g, and 420.6|g, respectively. The
217RN6cG 320-keV gamma, however, was not confirmed by 1989Ac01 or 1997Li12,
217RN7cG therefore, is not given here.
217RN cG RI$Relative photon intensities from 1997Li12 normalized at 149.2|g to
217RN2cG 100, except where noted. The intensities measured by 2015Ah04,
217RN3cG 1989Ac01 and 1961Ru06 are re-normalized by the evaluators to
217RN4cG I(149.2|g)=100.
217RN cG M$From the Adopted Gammas. For cases where the multipolarity arises
217RN2cG from this dataset, supporting evidence is included in the comments.
217RN cL E$From a least-squares fit to E|g, by evaluators, except where noted.
217RN cL J$From the Adopted Levels
217RN cL T(P)$From prompt (|a)(ce)(t) data (1989Ac01)
217RN cL E(a)$Deduced by evaluators using Q|a=6880.4 {I20} (2017Wa10) and
217RN2cL measured E|a.
217RN D CC$FROM BrIcc v2.3b (16-Dec-2014) 2008Ki07, "Frozen Orbitals" appr.
221RA P 0.0 5/2+ 28 S 2 6880.4 20
217RN N 0.125 20 1.0
217RN cN NR$relative photon intensities, normalized at 149.2|g to 100, and
217RN2cN intensities per 100 |a decays were listed by 1997Li12 with
217RN3cN I(149.2|g)=12.5% given. The method of obtaining absolute
217RN4cN intensities was not discussed by the authors.
217RN4cN Uncertainty assumed by evaluators taking similar uncertainty
217RN5cN which was obtained in 1961Ru06. Earlier measurement:
217RN6cN I(149|g)=13% {I2}, obtained by 1961Ru06 by (|a)(|g) coincidences.
217RN G 142.1 3 0.05 2
217RN L 0.0 9/2+ 0.54 MS 5
217RN cL T$from 1961Ru06
217RN A 6754 32 2 14.9 15
217RN cA $Other: E{-|a}=6761 {i5}, I{-|a}=30 {i2} (1961Ru06).
217RN L 88.89 4 (11/2+) 1.5 NS LE P
217RN G 88.90 5 7.5 10 (M1) 3.59
217RNS G LC=2.73 4$MC=0.649 10$NC=0.1693 24$OC=0.0370 6$PC=0.00541 8
217RN cG M$deduced from intensity balance.
217RN A 6667 1.5 LT134 GT
217RN cA E$deduced by evaluators, from level energy of 89-keV in 1997Li12
217RN2cA who indicate an upper limit for the alpha branch to the level.
217RN L 93.00 4 (7/2+) 4.0 NS 4
217RN cL T$from (|a)(93 L x-ray)(t) (1989Ac01)
217RN cL $Intensity imbalance at this level, which might be explained by the
217RN2cL unobserved 4.11|g.
217RN G 4.12 8 S
217RN cG $Transition was not observed. Its existence was deduced by 1997Li12
217RN2cG from observation of the 88.9|g in coincidence with the 6662|a to the
217RN3cG 93-keV level.
217RN G 93.02 5 33 3 E2(+M1) 11.33
217RN cG E$Others: 93.1 {I2} (1989Ac01), 89 {I2} (1961Ru06)
217RN cG RI$Others: 24 {I3} (1989Ac01), 115 {I16} (1961Ru06, presumably
217RN2cG includes the Rn K-x rays and the 88.9|g)
217RN cG M$(L1+L2)/L3=2.2 {i2} (1989Ac01; not corrected for possible
217RN2cG ceK(174|g)contribution on L1 line). Consistent with E2 but there
217RN3cG might be very small contribution of M1.
217RN cG CC$From BrIcc code assuming E2 because the contribution of M1 is very
217RN2cG small.
217RN A 6662 23 3 9.1 14
217RN cA $Other: E{-|a}=6668, I{-|a}=20 {i2} (1961Ru06).
217RN L 149.14 3 5/2+ 1.5 NS LE P
217RN G 56.19 6 2.5 5 (M1) 13.71
217RNL G FL=93.00
217RNS G LC=10.43 15$MC=2.48 4$NC=0.646 10$OC=0.1414 21$PC=0.0206 3
217RN cG E$weighted average of 56.16 {I5} (1997Li12) and 56.3 {I1} (2015Ah04).
217RN2cG Other: 56.2 {I2} (1989Ac01)
217RN cG RI$from 1997Li12. Others: 13.7 {I17} (2015Ah04), 3.1 {I4} (1989Ac01)
217RN cG M$deduced from intensity balance
217RN G 149.13 3 100 E2 1.577
217RNS G KC=0.284 4$LC=0.955 14$MC=0.257 4$NC=0.0668 10$OC=0.01354 19$
217RNS G PC=0.001527 22
217RN cG E$weighted average of 149.2 {I1} (1997Li12) and 149.12 {I3}
217RN2cG (2015Ah04). Others: 149.0 {I1} (1989Ac01), 152 {i2} (1961Ru06)
217RN cG M$(L1+L2)/L3=1.72 {i9} (1989Ac01), |a(L1+L2)exp=0.46 {I12},
217RN2cG |a(L3)exp=0.34 {I9} (2015Ah04)
217RN A 6607 38 4 3.3 5
217RN cA $Other: E{-|a}=6613, I{-|a}=34 {i2} (1961Ru06).
217RN L 174.29 6 (7/2,9/2,11/2)+ 1.5 NS LE P
217RN G 81.3 S
217RNL G FL=93.00
217RN cG $This transition was not observed. It would be obscured by the K-x
217RN2cG rays. It is tentatively proposed by 1997Li12.
217RN G 85.4 3 0.15 5
217RNL G FL=88.89
217RN G 174.29 8 16.8 17 (M1) 2.71
217RNS G KC=2.19 3$LC=0.396 6$MC=0.0940 14$NC=0.0245 4$OC=0.00536 8$
217RNS G PC=0.000782 11
217RN cG E$weighted average of 174.3 {I1} (1997Li12) and 174.28 {I8}
217RN2cG (2015Ah04) Others: 174.1 {I2} (1989Ac01), 176 {i2} (1961Ru06).
217RN cG RI$weighted average of 17 {I2} (1997Li12) and 16.6 {I17} (2015Ah04).
217RN2cG Others: 18 {I2} (1989Ac01), 15 {I4} (1961Ru06)
217RN cG M$deduced from intensity balance.
217RN A 6579 5.6 2418 8
217RN cA $Other: E{-|a}=6591, I{-|a}=8 {i1} (1961Ru06).
217RN L 184 a ?
217RN A 6581
217RN cA E$from 1961Ru06 using the level energy given as 184 keV by 1961Ru06.
217RN2cA This level energy and author's E{-|a}(to g.s.) of 6761 give
217RN3cA E{-|a}=6573.
217RN cA IA$3 {I1} was measured by 1961Ru06. If this alpha indeed belongs to
217RN2cA {+221}Ra decay, the intensities of other alpha transitions will have
217RN3cA to be decreased by a factor of 0.97, so that the sum of all I{-|a}'s
217RN4cA will be 100%.
217RN L 234.7 3 (3/2+)
217RN G 86.0 5 0.04 2
217RN A 6526 0.3 193
217RN L 295 a ?
217RN A 6463 0.05 AP664 AP
217RN cA $Other: E{-|a}=6470, I{-|a}=0.4 {i3} (1961Ru06). This alpha was
217RN2cA tentatively assigned by 1961Ru06 and 1997Li12.
217RN L 374.90 19
217RN G 140.3 3 0.04 2
217RN G 225.7 2 0.2 1
217RN A 6390 0.1 AP156 AP
217RN cA $E{-|a}=6410, I{-|a}=0.3 {i2} (1961Ru06) is assumed to be the 6390|a
217RN2cA observed by 1997Li12. This alpha was tentatively assigned by 1961Ru06
217RN3cA to this decay.
217RN L 382.15 13 (5/2+,7/2,9/2+)
217RN G 207.9 2 0.6 2
217RN G 232.9 3 0.2 1
217RN G 289.1 3 0.7 2
217RN G 382.2 3 0.3 1
217RN A 6382 0.4 36
217RN L 474.5 4
217RN G 474.5 4 0.35 12
217RN A 6287 0.05 AP119 AP
217RN L 500 a ?
217RN A 6260
217RN cA IA$0.7 {i3} (1961Ru06).
217RN cA E$from 1961Ru06. From the level energy of 500 keV, given
217RN2cA 1961Ru06, and the author's E{-|a} (to g.s.)=6761, E=6270 is calculated.
217RN3cA This tentatively assigned alpha was not confirmed by others;
217RN4cA therefore, is considered questionable.
217RN L 569.64 16
217RN G 395.2 3 0.3 1
217RN G 420.6 2 0.7 2
217RN G 476.5 4 0.40 15
217RN A 6195 0.2 12
217RN L 600 a ?
217RN A 6170
217RN cA E$from 1961Ru06. From the level energy of 600 keV, given in
217RN2cA 1961Ru06, and the author's E{-|a} (to g.s.)=6761 yield E{-|a}=6172.
217RN3cA This alpha was not confirmed by others; therefore, is considered
217RN4cA questionable.
217RN cA IA$0.3 {i2} (1961Ru06).
217RN L 618.8 3
217RN G 444.3 5 0.2 1
217RN G 469.7 5 0.15 6
217RN G 525.8 4 0.15 5
217RN A 6147 0.05 AP28 AP