231TH 231AC B- DECAY (7.5 M) 1999AA03,1986GI08,1973CH2422NDS 202210
231TH H TYP=FUL$AUT=Balraj Singh, Jagdish K. Tuli, and Edgardo Browne$
231TH2 H CIT=NDS 185, 560 (2022)$CUT=31-Aug-2022$
231TH c 1999Aa03: {+231}Ac produced in spallation of 1-GeV protons on a
231TH2c {+231}Th target, and subsequently mass separated in the ISOLDE-CERN
231TH3c mass separator. Measured E|g, I|g, level half-lives by |b|g|g(t) fast
231TH4c timing method using HPGe detector for |g radiation and plastic
231TH5c scintillator for |b{+-}. The E|g values in this work seem to be
231TH6c nominal values with no stated uncertainties. Deduced |g-transition
231TH7c probabilities from measured level half-lives, known multipolarities
231TH8c and |g-ray branching ratios, and compared with detailed
231TH9c quasiparticle-plus-phonon model (QPM) calculations with Coriolis
231THAc coupling.
231TH c 1986Gi08: {+231}Ac produced by bombarding targets of natural tungsten
231TH2c with 2.7-GeV {+238}U ions from UNILAC at GSI, followed by mass
231TH3c separation. Measured E|g, I|g, x rays, |b|g-coin using HPGe detector
231TH4c for |g radiation and plastic scintillator for |b{+-}. Deduced |g-ray
231TH5c multipolarities from x-ray and |g-ray data.
231TH c 1985Hi02: {+231}Ac as daughter product in spallation of {+238}U by
231TH2c 600 MeV protons. Measured K x-ray, |g, K x-ray(t) using Ge(Li)
231TH3c detectors. Energies and intensities of six |g rays given as well
231TH4c as intensity of Th K-x rays
231TH c 1973Ch24: {+231}Ac produced In {+232}Th(|g,p),E=150 MeV
231TH2c bremsstrahlung; and {+232}Th(n,pn),E=14 MeV, followed by chemical
231TH3c separation at Mainz. Measured T{-1/2}=7.5 min {I1}, energies and
231TH4c intensities of 22 |g rays, |b{+-}, Th x-rays, x-ray(t), |g(t) using
231TH5c Ge(Li) detectors for |g and x rays and scintillation detector
231TH6c for |b radiation.
231TH c 1960Ta19: measured an activity with T{-1/2}=15 min {I1},
231TH2c E|b=2100 keV {I100}, |g rays of 85- and 185-keV, and very weak and
231TH3c uncertain |g rays of 280-, 390-, and 710 keV. The disagreement in the
231TH4c half-life value and in the intensity of the 280-keV |g ray (the
231TH5c strongest from {+231}Ac) suggest that this activity is not {+231}Ac. It
231TH6c may be due to Tellurium (1999Aa03,1973Ch24).
231TH c Th K x-ray intensity of 45.6% {I27}, relative to I|g(282|g)=39.0%
231TH2c {I16}, deduced by evaluators using the computer program RADLST and the
231TH3c |g-ray data presented here, compared with an experimental value of
231TH4c 37.0% {I16} (1985Hi02). Measured I(K x-ray)=95 {I4} with
231TH5c I|g(282|g)=100 {I8}. A total average radiation energy of
231TH6c 2065 keV {I74}, deduced by evaluators using the computer program
231TH7c RADLST, compared with Q(|b{+-})=1947 keV {I13} from 2021Wa16.
231TH8c These results reflect the consistency of the decay scheme.
231TH c Evaluators' note about the decay scheme: spectral information for
231TH2c seven low-energy transitions (19-51 keV) is limited and makes the
231TH3c decay scheme incomplete in that respect.
231TH cG $Measured intensity of Th K-x rays=95 {I4} relative to 100 for 282.5|g
231TH2cG (1985Hi02), uncertainty on intensity is statistical only.
231TH cG $Following eight |g rays reported by 1973Ch24 were not seen by 1999Aa03
231TH2cG and 1986Gi08: 68.8 (I|g=5 {I3}), 350.7 (I|g=2.4 {I4}),
231TH3cG 375.7 (I|g=4.1 {I6}), 396.9 (I|g=1.9 {I3}), 400.2 (I|g=2.6 {I4}),
231TH4cG 503.5 (I|g=1.1 {I2}), 512.4 (I|g=1.2 {I2}), 528.1 (I|g=2.3 {I4}),
231TH5cG 554.4 (I|g=3.9 {I6}); intensities relative to 100 for 282.5|g.
231TH cG E$From the Adopted Levels, Gammas dataset, where values from
231TH2cG (n,|g) and {+235}U |a decay are more precise than those available
231TH3cG from {+231}Ac |b{+-}. Measured values from {+231}Ac decay are listed
231TH4cG under comments. Exceptions are noted.
231TH cG E(x),RI(x)$This |g was not seen by 1999Aa03 with only an upper limit
231TH2cG of I|g deduced from the spectrum. This |g is not listed in the
231TH3cG Adopted dataset
231TH cG E(y),RI(y)$From 1999Aa03, derived either from the |g|g-coin data or
231TH2cG from intensity balance arguments, with the assumption of no direct |b
231TH3cG feeding to levels below 500 keV
231TH cG TI$From |g-ray transition intensity balance
231TH cG M$From conversion coefficients deduced from the intensities of
231TH2cG x-rays and |g rays measured in coincidence mode (1986Gi08). However,
231TH3cG conversion coefficients are not given by 1986Gi08.
231TH4cG Exceptions are noted
231TH cG MR$From the Adopted Levels, Gammas dataset
231TH cL $1973Ch24 placed the 396.9-, 503.5-, and 528.1-keV, deexciting
231TH2cL levels at 713 and 820 keV. 1999Aa03, however, have interpreted these
231TH3cL transitions as due to sum peaks in the |g-ray spectrum. Therefore, the
231TH4cL existence of these levels could not be confirmed.
231TH cL E$Deduced from least-squares fit to |g-ray energies.
231TH cL J$From the Adopted Levels
231TH cL T$From |b|g|g(t) (1999Aa03), unless otherwise specified
231AC P 0.0 1/2+ 7.5 M 1 1947 13
231AC cP J,T$From {+231}Ac Adopted Levels.
231AC2cP Nilsson configuration=|p1/2[400]
231AC cP QP$From 2021Wa16
231TH N 0.389 18 0.389 18 1.0 1.0
231TH PN 4
231TH cN NR$From |SI(|g+ce)=100 to g.s. and 42 level, not including the
231TH2cN transition intensity of the 42-keV transition. No |b{+-} feeding is
231TH3cN expected to the g.s. and the 42-keV level due to |DJ|p involved
231TH L 0.0 5/2+ 25.57 H 8
231TH cL T$from the Adopted Levels.
231TH L 41.951 2 7/2+
231TH G 41.98 5 0.09 2 M1+E2 0.95 10 3.7E2 4 38 3 S
231TH2 G %IG=0.040 5$
231THS G LC=330 70 $MC=89 20 $NC=24 6
231THS G OC=5.3 12 $ PC=0.88 19 $ QC=0.0063 10
231TH cG RI$from I(|g+ce)=38 {I3} (1999Aa03) and |a=440 {I100}. 1999Aa03 give
231TH2cG I|g=0.08 {I2} using |a=450 {I80}. Other I(|g+ce)=37.0 (1986Gi08).
231TH cG M,MR$from the Adopted dataset
231TH L 185.716 2 5/2- 1.073 NS 79
231TH cL T$1999Aa03 compared their value with 0.77 ns {I12} from 1959St49
231TH2cL measured in {+235}U |a decay, and explained the discrepancy as due
231TH2cL to the latter value measured using NaI(Tl) detectors, thus affected
231TH4cL by |g rays other than those due to direct feeding and deexcitation
231TH5cL of the 185.7-keV level.
231TH B 1.9 11 8.5 3 1U?
231THS B EAV=592.4 50
231TH G 143.765 2 8.6 5 E1 0.207 3
231TH2 G %IG=3.35 25$
231TH cG E$143.7 {I2} (1986Gi08), 143.6 {I2} (1973Ch24) in |b{+-} decay
231TH cG RI$weighted average: 8.6 {I5} (1999Aa03), 8.5 {I9} (1986Gi08),
231TH2cG 8.3 {I11} and 10 {I3} (1973Ch24)
231THS G KC=0.1618 24$LC=0.0345 5$MC=0.00834 12$
231THS G NC=0.00220 4$OC=0.000504 8$PC=9.10E-5 14$QC=5.86E-6 9
231TH G 185.713 2 41.9 20 E1 0.1125 16
231TH2 G %IG=16.3 11$
231TH cG E$185.7 {I2} (1986Gi08), 185.6 {I2} (1973Ch24),
231TH2cG 185.68 {I2} (1985Hi02, statistical uncertainty only) in |b{+-} decay
231TH cG RI$Mandel-Paule average: 43.0 {I20} (1999Aa03), 38.0 {I20} (1986Gi08),
231TH2cG 42.8 {I8} (1985Hi02, statistical uncertainty only), 43 {I5} and
231TH3cG 49 {I9} (1973Ch24)
231THS G KC=0.0887 13$LC=0.0180 3$MC=0.00433 7$
231THS G NC=0.001143 17$OC=0.000263 4$PC=4.82E-5 7$QC=3.32E-6 5
231TH L 205.310 2 (7/2-)
231TH G 19.55 5 0.006 LE [M1] 114.7 19 0.6 2 S
231TH2 G %IG LE 0.0020 $
231TH cG RI$from 1999Aa03, based on estimated I(|g+ce) and |a for M1
231TH G 163.357 2 S
231TH G 205.311 2 S
231TH L 221.3985 10 3/2+ 74 PS LE
231TH B 9 LT 6.8 GT ?
231THS B EAV=604.8 53
231TH cB $I|b=9 {I8} from transition intensity balance, 3.6 {I52} from
231TH2cB 100-(I|b(593)+I|b(554)+I|b(186)), consistent with almost zero feeding
231TH G 221.392 20 45.3 34 M1 1.96 3
231TH2 G %IG=17.6 16$
231TH cG E$221.2 {I2} (1986Gi08), 221.2 {I2} (1973Ch24),
231TH2cG 221.38 {I1} (1985Hi02, statistical uncertainty only) in |b{+-} decay
231TH cG RI$Mandel-Paule average: 48.2 {I24} (1999Aa03), 39.7 {I20} (1986Gi08),
231TH2cG 45.4 {I4} (1985Hi02, statistical uncertainty only), 49 {I6} and
231TH3cG 56 {I9} (1973Ch24)
231THS G KC=1.566 22$LC=0.296 5$MC=0.0712 10$
231THS G NC=0.0190 3$OC=0.00450 7$PC=0.000873 13$QC=8.28E-5 12
231TH L 240.877 2 5/2+
231TH G 198.927 3 7.2 8 M1 2.64 4
231TH2 G %IG=2.80 34$
231TH cG E$198.9 {I2} (1986Gi08), 198.9 {I2} (1973Ch24) in |b{+-} decay
231TH cG RI$weighted average: 6.6 {I12} (1999Aa03), 7.5 {I8} (1986Gi08),
231TH2cG 7.2 {I10} and 6 {I3} (1973Ch24)
231THS G KC=2.11 3$LC=0.401 6$MC=0.0963 14$
231THS G NC=0.0257 4$OC=0.00608 9$PC=0.001180 17$QC=0.0001120 16
231TH G 240.876 4 10.4 6 M1(+E2) 0.3 3 1.45 22
231TH2 G %IG=4.05 30$
231TH cG E$240.9 {I2} (1986Gi08), 240.6 {I2} (1973Ch24),
231TH2cG 240.89 {I5} (1985Hi02, statistical uncertainty only) in |b{+-} decay
231TH cG RI$Mandel-Paule average: 11.3 {I8} (1999Aa03), 9.4 {I9} (1986Gi08),
231TH2cG 10.5 {I9} (1985Hi02, statistical uncertainty only),
231TH3cG 11.0 {I14} and 6 {I3} (1973Ch24)
231THS G KC=1.14 21$LC=0.228 13$MC=0.0553 21$
231THS G NC=0.0148 6$OC=0.00348 16$PC=0.00067 5$QC=6.1E-5 11
231TH L 247.587 2 1/2+ 74 PS LE
231TH B ?
231THS B EAV=594.3 53
231TH cB IB$-7 {I11}, consistent with zero feeding
231TH G 26.2 0.6 LE [M1] 192 4 97 17y S
231TH2 G %IG LE 0.20$
231TH cG $|a(theory) for assumed 0.1 keV uncertainty in transition energy
231TH cG RI$from 1999Aa03, based on estimated I(|g+ce) (1999Aa03) and |a for M1.
231TH2cG Other I(|g+ce)=74.7 (1986Gi08).
231TH G 247.586 3 1.13 20 E2 0.312 5
231TH2 G %IG=0.44 8$
231TH cG E$247.4 {I2} (1986Gi08), 247.4 {I2} (1973Ch24) in |b{+-} decay
231TH cG RI$weighted average: 1.5 {I4} (1999Aa03), 0.7 {I5} (1986Gi08),
231TH2cG 1.1 {I2} (1973Ch24)
231THS G KC=0.1065 15$LC=0.1512 22$MC=0.0409 6$
231THS G NC=0.01096 16$OC=0.00247 4$PC=0.000421 6$QC=7.18E-6 11
231TH L 272.181 2 3/2+
231TH B ?
231THS B EAV=584.4 52
231TH cB IB$3 {I9}, consistent with zero feeding
231TH G 24.6 0.15 9 [M1] 231 5 35 20y S
231TH2 G %IG=0.058 35
231TH cG $|a(theory) for assumed 0.1 keV uncertainty in transition energy
231TH cG RI$from 1999Aa03, based on estimated I(|g+ce) (1999Aa03) and |a for M1.
231TH G 31.3 0.5 LE (M1) 114 2 54 3 y S
231TH2 G %IG LE 0.18
231TH cG $|a(theory) for assumed 0.1 keV uncertainty in transition energy
231TH cG RI$from 1999Aa03, based on estimated I(|g+ce) (1999Aa03) and |a for M1.
231TH2cG Other I(|g+ce)=50.9 (1986Gi08)
231TH cG M$from 1986Gi08, based on measured |a(L)exp from the observed
231TH2cG intensity of L x-rays in coincidence with the 241|g.
231TH G 50.8 0.7 LE [M1] 27.3 5 20 LEy S
231TH2 G %IG LE 0.28
231TH cG $|a(theory) for assumed 0.1 keV uncertainty in transition energy
231TH cG RI$from estimated I(|g+ce)=37 {I4}-I(|g+ce)(24.6|g) (1999Aa03)
231TH2cG and |a for M1. Note that in Table 2, 1999Aa03 give I|g|<1.3.
231TH3cG Other: I(|g+ce)=39.0 (1986Gi08).
231TH G 230.243 11 0.37 11 [E2] 0.399 6 S
231TH2 G %IG=0.14 4$
231TH cG RI$from |g-branching ratio in the Adopted dataset
231THS G KC=0.1223 18$LC=0.203 3$MC=0.0551 8$
231THS G NC=0.01476 21$OC=0.00332 5$PC=0.000564 8$QC=8.57E-6 12
231TH G 272.181 2 6.7 8 M1+E2 0.64 10 0.85 6
231TH2 G %IG=2.61 33$
231TH cG E$271.9 {I2} (1986Gi08), 271.9 {I2} (1973Ch24) in |b{+-} decay
231TH cG RI$weighted average: 6.8 {I8} (1999Aa03), 6.3 {I8} (1986Gi08),
231TH2cG 6.7 {I10} and 9 {I3} (1973Ch24)
231THS G KC=0.65 6$LC=0.148 5$MC=0.0365 10$
231THS G NC=0.00975 25$OC=0.00228 7$PC=0.000432 15$QC=3.5E-5 3
231TH L 554.651 2 (1/2)- 503 PS 12
231TH cL $1973Ch24 placed 512.4- and 554.4- |g rays deexciting this level. These
231TH2cL |g rays, however, have been interpreted as sum peaks in the spectrum
231TH3cL (1999Aa03).
231TH cL $Configuration=|n1/2[501]
231TH B 88 5 5.51 3
231THS B EAV=472.7 51
231TH G 282.471 2 100 3 E1 0.0425 6
231TH2 G %IG=38.9 21$
231TH cG E$282.3 {I2} (1986Gi08), 282.3 {I2} (1973Ch24),
231TH2cG 282.46 {I1} (1985Hi02, statistical uncertainty only) in |b{+-} decay
231TH cG RI$100 {I3} (1999Aa03), 100.0 {I30} (1986Gi08), 100 {I8} (1985Hi02),
231TH2cG 100 {I10} (1973Ch24)
231THS G KC=0.0340 5$LC=0.00644 9$MC=0.001546 22$
231THS G NC=0.000409 6$OC=9.50E-5 14$PC=1.768E-5 25$QC=1.341E-6 19
231TH G 307.063 2 78.5 9 E1 0.0353 5
231TH2 G %IG=30.5 15$
231TH cG E$306.9 {I2} (1986Gi08), 306.9 {I2} (1973Ch24),
231TH2cG 307.05 {I1} (1985Hi02, statistical uncertainty only) in |b{+-} decay
231TH cG RI$Mandel-Paule average: 76.9 {I26} (1999Aa03), 75.2 {I25} (1986Gi08),
231TH2cG 79.1 {I9} (1985Hi02, statistical uncertainty only), 77 {I9} and
231TH3cG 84 {I13} (1973Ch24)
231THS G KC=0.0283 4$LC=0.00530 8$MC=0.001270 18$
231THS G NC=0.000336 5$OC=7.82E-5 11$PC=1.459E-5 21$QC=1.126E-6 16
231TH G 333.3 0.5 LE x ?
231TH2 G %IG LE 0.19
231TH G 368.934 2 38.8 7 E2 0.0927 13
231TH2 G %IG=15.1 7$
231TH cG E$368.8 {I2} (1986Gi08), 368.8 {I2} (1973Ch24),
231TH2cG 368.93 {I1} (1985Hi02, statistical uncertainty only) in |b{+-} decay
231TH cG RI$Mandel-Paule average: 38.3 {I24} (1999Aa03), 36.0 {I15} (1986Gi08),
231TH2cG 39.6 {I5} (1985Hi02, statistical uncertainty only), 38 {I5} and
231TH3cG 37 {I7} (1973Ch24)
231THS G KC=0.0485 7$LC=0.0326 5$MC=0.00865 13$
231THS G NC=0.00232 4$OC=0.000526 8$PC=9.18E-5 13$QC=2.85E-6 4
231TH G 512.7 0.9 LE x ?
231TH2 G %IG LE 0.35
231TH cG $Existence of this transition (from (1/2)- to 7/2+) is unlikely as it
231TH2cG involves mult=E3
231TH G 554.7 0.6 LE x ?
231TH2 G %IG LE 0.23
231TH L 593.618 2 (3/2)- 98 PS 36
231TH B 6.5 7 6.60 5
231THS B EAV=457.5 51
231TH G 39.0 0.040 LE [M1] 59.5 10 2.4 LEx S
231TH2 G %IG LE 0.016
231TH cG RI$from I(|g+ce)|<2.4 from model calculations (1999Aa03) and |a for M1
231TH G 321.7 0.7 LE x ?
231TH2 G %IG LE 0.27
231TH G 346.1 2 1.4 3 [E1] 0.0272 4
231TH2 G %IG=0.54 12$
231TH cG E$from 1986Gi08
231TH cG RI$weighted average: 1.5 {I3} (1999Aa03), 1.2 {I5} (1986Gi08)
231THS G KC=0.0218 3$LC=0.00402 6$MC=0.000963 14$
231THS G NC=0.000255 4$OC=5.94E-5 9$PC=1.113E-5 16$QC=8.80E-7 13
231TH G 352.7 0.3 LE x ?
231TH2 G %IG LE 0.12
231TH G 372.221 2 4.0 7 E1 0.0233 3
231TH2 G %IG=1.56 28$
231TH cG E$372.0 {I2} (1986Gi08), 372.0 {I2} (1973Ch24) in |b{+-} decay
231TH cG RI$weighted average: 4.1 {I11} (1999Aa03), 3.4 {I8} (1986Gi08),
231TH2cG 4.4 {I7} (1973Ch24)
231THS G KC=0.0187 3$LC=0.00342 5$MC=0.000817 12$
231THS G NC=0.000216 3$OC=5.05E-5 7$PC=9.49E-6 14$QC=7.60E-7 11
231TH G 388.3 2 0.81 26 [E2] 0.0806 11
231TH2 G %IG=0.32 10$
231TH cG E$from 1973Ch24
231TH cG RI$weighted average: 0.58 {I18} (1999Aa03), 1.1 {I2} (1973Ch24)
231THS G KC=0.0438 7$LC=0.0272 4$MC=0.00719 11$
231THS G NC=0.00192 3$OC=0.000437 7$PC=7.66E-5 11$QC=2.55E-6 4
231TH cG E$Not seen in {+230}Th(n,|g) (I|g<0.4).
231TH G 407.899 2 8.5 9 E2 0.0708 10
231TH2 G %IG=3.3 4$
231TH cG E$407.8 {I2} (1986Gi08), 407.8 {I2} (1973Ch24) in |b{+-} decay
231TH cG RI$weighted average: 8.3 {I16} (1999Aa03), 8.5 {I9} (1986Gi08),
231TH2cG 8.5 {I12} and 9 {I4} (1973Ch24)
231THS G KC=0.0398 6$LC=0.0229 4$MC=0.00604 9$
231THS G NC=0.001616 23$OC=0.000368 6$PC=6.47E-5 10$QC=2.29E-6 4
231TH cG M$from the Adopted dataset. 1986Gi08 reported M1.
231TH G 593.6 0.8 LE x ?
231TH2 G %IG LE 0.31