234PA 234TH B- DECAY 26NDS 202601
234PA H TYP=FUL$AUT=S. Ota$CIT=NDS 207, 351 (2026)$CUT=1-Dec-2023$
234PA dL E$Least-squares fitting is done by GLSC (version 17-Jul-2025)
234PA c 2016Ri06: {+234}Th source was prepared by chemically isolating
234PA2c thorium chloride solution from 10 g of natural uranium ({+238}U decay
234PA3c to thorium) with 6 mol hydrochloric acid on KU2 cation exchanger. The
234PA4c thorium chloride solution was left for 3 days for {+231}Th activity
234PA5c to decay away, finally run through an ion-exchange column with
234PA6c AV17kh8 anion exchanger to remove Pa fraction, and the obtained
234PA7c solution was deposited onto and dried on a filter paper.
234PA8c Approximately 20 kBq {+234}Th activity was confirmed in a spot with a
234PA9c 4 mm diameter and then the source was wrapped in a copper foil (50
234PAac |mm thick) to suppress soft X-rays and placed between two HPGe
234PAbc detectors. Measured E|g, I|g, |g|g-coin, (x ray)|g-coin. Deduced
234PAcc tentative absolute energy of the 1.159-min, (0-) isomer in {+234}Pa,
234PAdc to be 2.6 {I5} keV from the energy difference between the ground
234PAec state transition (106|g) and the sum of the two other indirect
234PAfc transitions (29.49|g+73.92|g).
234PA c 2006Vi12 (in Russian): Measured K-shell internal conversion
234PA2c coefficient for 112.8|g from {+234}Th |b{+-} decay.
234PA c 2004Ab03: Measured %I|g(63.29|g) using %I|g(59.41|g) in {+241}Am
234PA2c decay (|g from {+237}Np following |a decay) as a reference with a
234PA3c planar HPGe detector. The mixed {+238}U (|a decay to
234PA4c {+234}Th)-{+241}Am solutions (about 500 mg {+238}U and 200 ng
234PA5c {+241}Am) kept in polyethelene bottles were placed at 4 cm distance
234PA6c from the Ge. The detector and sample were incorporated in a
234PA7c copper-lined lead-shielded cavity. Note that the doublet {62.86|g}
234PA8c contribution is very tiny but subtracted.
234PA c 1992Li05: The {+238}U source, a foil of normal uranium metal (202.82
234PA2c mg), was measured with a Ge housed in a lead shield. Determined the
234PA3c intensities of 92.38|g from {+234}Th |b{+-} decay and other |g-rays
234PA4c from {+238} progeny.
234PA c 1990Sc09: |g emission probabilities of the daughters of {+238}U were
234PA2c measured with a HPGe detector. U samples of known mass and isotopic
234PA3c concentration in aqueous solution were used. The |g measurements were
234PA4c performed in the shield made of low-activity lead which was lined
234PA5c with cadmium and copper. Each sample was measured up to 200,000
234PA6c counts, which needed approximately a month for total of six samples
234PA7c due to the low sample activity. After a two-month waiting period,
234PA8c another month-long measurements were performed. Determined the
234PA9c emission probability of 63.24 {I1} |g from {+234}Th |b{+-} decay.
234PA c 1982Mo30: Measured |g-rays from a natural uranium ore with a Ge(Li)
234PA2c detector housed in a 12 cm thick steel shield and determined relative
234PA3c intensities from various nuclides in the uranium series, including
234PA4c 63.34|g and 92.75|g from {+234}Th |b{+-} decay.
234PA c 1978Ch06: {+234}Th source was measured with a Ge(Li) detector,
234PA2c determining relative intensities of a number of |g decays from
234PA3c {+234}Th. The measurements were performed far enough from the source
234PA4c to avoid coincidence summing, etc. Some measurements were made more
234PA5c than a month apart as well. The source was prepared as follows: Th
234PA6c was first separated from the bulk of U by passing a 0.5 N HNO{-3}
234PA7c solution containing about 300 g of uranyl oxide through a Dowex-50
234PA8c cation exchange column. After washing and eluting, Th was
234PA9c coprecipitated with ferric hydroixde. Then Th was separated from iron
234PAac and the remaining U. The intensity of the {+234}Th source obtained
234PAbc was about 50 |mCi.
234PA c 1973Sa33: Precisely measured 63.28|g, 92.36|g, and 92.79|g from
234PA2c {+234}Th |b{+-} decay and determined the relative intensity of the
234PA3c 92.36|g and 92.79|g doublet. A {+238}U metal sample (decays to
234PA4c {+234}Th) was measured with a thin window Ge(Li) detector.
234PA c 1973Go40 (in French): Studied {+234}Th |b{+-} decay with two
234PA2c iron-free double focusing spectrometers and several Ge(Li) detectors.
234PA3c Determined intensities of |g-rays, x-rays, and conversion electrons.
234PA c Measured |b|g: 1963Bj02, 1956On07, 1955De40, 1954Jo19
234PA c Measured |g|g: 1973Go40, 1962Ad01, 1954Jo19
234PA cB IB$All |b branchings have been deduced from intensity balance at each
234PA2cB level by the evaluator.
234PA cG $Ice's given here are from 1973Go40. The original intensities have
234PA2cG been renormalized by the evaluators such that |a(L1)(92.38|g)=3.54
234PA3cG {I5}, theoretical value (BRICC).
234PA cG E$Measurements by 1973Go40 (s ce, semi |g). These measurements are in
234PA2cG agreement with the measurements by 1978Ch06 (semi |g), 1963Bj02 (s
234PA3cG ce), 1962Fo11 (s ce), 1961Ge13 (s ce). The authors of 1973Sa33
234PA4cG (Ge(Li) x-ray) and 1973Ta25 (Si(Li)) measured E|g's for the doublets
234PA5cG in 63- and 92-keV peaks. Their measured energies are given for
234PA6cG comparison.
234PA cG RI$Relative photon intensities are from 1978Ch06, unless otherwise
234PA2cG noted.
234PA cG M,MR$From ce data of 1973Go40. See also 1962Fo11 and 1963Bj02.
234PA2cG Multipolarities in square brackets are from level scheme.
234PA cL E$From the Adopted Levels
234PA cB $Other |b{+-} measurements: 1946Jn01, 1947Br01, 1954Jo19, 1956On07.
234PA D Transition strength is calculated by Java-RULER (version 28-Apr-2022)
234PA D NR, CC (from ^BRICC) changed but IB, LOGFT not changed as yet.
234PA D EAV,LOGFT$FROM BetaShape v2.4 (Jun-2024) 2023MO21.
234PA D CC$FROM BrIcc v2.3e (17-Jun-2020) 2008Ki07, "Frozen Orbitals" appr.
234PA DB EAV,LOGFT$FROM BetaShape v2.4 (Jun-2024) 2023MO21.
234TH P 0.0 0+ 24.10 D 3 274 3
234TH cP QP$From 2021WA16
234PA N 0.0050 4 1.0 1.0
234PA cN NR$Normalize to %I|g(63.29|g + 62.86|g)=3.72 {I7} (thus I|g
234PA2cN normalization factor=0.0050 {I4} [3.72/736]): weighted average of
234PA3cN 3.743 {I71} (2004Ab03) and 3.65 {I11}. The latter value has been
234PA4cN calculated from I|g(63.29|g + 62.86|g)/I|g(1001|g in {+234m}Pa |b-
234PA5cN Decay)=4.32 {I12} [weighted average of 4.40 {I30} (1982Mo30;
234PA6cN 0.0405/0.0092 5% error for each) and 4.29 {I13} (1990Sc09; 360
234PA7cN {I10}/83.9 {I4})], and %I|g(1001|g)=0.843 {I8} [value recommended by
234PA8cN the evaluators (See {+234m}Pa |b- Decay)].
234PA cN NR$%I|g(92.38|g + 92.80|g)=5.57 {I28} reported in 1992Li05 disagrees
234PA2cN with 4.2% {I3} deduced by the evaluators from I|g(rel)(92.38|g +
234PA3cN 92.80|g)=846 {I32} with I|g normalization=0.0050 {I4}. Although the
234PA4cN cause for this disagreement has not been determined, it is plausible
234PA5cN that a 93.3-keV line from Th K|a{-1}| x ray (U decays to Th) may have
234PA6cN affected the results in 1992Li05. Note, however, the effect of
234PA7cN subtracting the x-ray contribution may be as tiny as 2% (of 5.57%,
234PA8cN thus 0.11%) as reported by 1973Sa33.
234PA PN 3
234PA G 57.75 10 1.0 6
234PA2 G %IG=0.005 +4-3
234PA cG RI$from 1973Go40.
234PA G 87.02 6 2.9 5 (M1+E2) 15 9
234PAS G LC=11 6$MC=2.9 18$NC=0.8 5$OC=0.18 11$PC=0.030 16$QC=7.E-4 5
234PA2 G %IG=0.015 4
234PA cG RI$1.4 {I2} was measured by 1973Go40.
234PA cG $Ice(L1)=5.7 {I4}; L1/M1=57 {I4}/23 {I4}=2.4 {I4}
234PA G 103.71 6
234PA cG $Ice(L1 103.71|g)=2.9 {I8}.
234PA G 108.00 5 1.6 2
234PA2 G %IG=0.0080 +17-16
234PA G 132.9
234PA cG $1973Go40 propose that the 132.9|g deexcites a 2+ state at 206.8+x
234PA2cG keV to the 0- level at 73.92+x keV.
234PA cG $Ice(K)=5.9 {I20}. The ce line observed at 111.78 keV with Ice=3.4
234PA2cG {I14} was assigned by 1973Go40 to L1(132.9|g); however, the ce line
234PA3cG observed at 112 keV was assigned by 1963Bj02 to {+234}Pa g.s. decay
234PA4cG (ce(K) 227.25|g).
234PA cG $I|g(132.9|g)=0.19 {I6}, if it is an M2 transition, as suggested by
234PA2cG 1973Go40.
234PA L 0.0 4+ 6.70 H 5
234PA L 73.920 20 (3+)
234PA G 73.92 2 2.6 2 (M1+E2) 0.11 3 10.57 33 *
234PAS G LC=7.96 24$MC=1.94 7$NC=0.520 18$OC=0.124 4$PC=0.0235 7$QC=0.001854 28
234PA2 G %IG=0.0130 15
234PA cG $Ice(L1)=13.2 {I3}; L1:L2:M1=132 {I3}:21 {I2}:42 {I2}.
234PA B 0.150 17 8.33 6 2U
234PAS B EAV=65.1 10
234PA L 76.5 4 (0-) 1.159 M 16 M1
234PA DL E LEVEL ENERGY HELD FIXED IN LEAST-SQUARES ADJUSTMENT
234PA cL $2016Ri06 deduces that this (0-) isomer lies 2.6 keV above the
234PA2cL 73.9-keV (3+) level, based on a tentative placement of a 106|g ground
234PA3cL state transition in coincidence with 63 |g (suggesting the 106|g from
234PA4cL the 103.42+2.6 (2-) level),
234PA G 2.6 5 [E3] S
234PAL G FL=73.92
234PA cG E$deduced by 2016Ri06 from observation of a 106-keV |g ray.
234PA2cG Evaluators consider it as a tentative energy due to tentative
234PA3cG placement of 106-keV |g ray
234PA cG $The |g transition was not observed. E|g was deduced also by 1973Go40
234PA2cG to be <10 keV from non-observation of its conversion electrons. Their
234PA3cG detection limit was 6 keV, and if there were conversion lines
234PA4cG belonging to this transition in the 6 keV113.6 keV. The K-binding energy for
234PA3cG protactinium is 112.6 keV; therefore, a large uncertainty on the
234PA4cG total conversion coefficient is given to reflect the uncertainty of
234PA5cG the |a(K) value. 2006Vi12 measured and reported the |a(K)=0.220 {I11}
234PA6cG and the energy is 112.790 {I2}.
234PA B (85) 3 1.5 7 7.13 21
234PAS B EAV=21.8 8
234PA cB $E|b=60 {I3} and I|b=5 (1973Go40)
234PA L 261.3 4 (1+)
234PA cL E,J$level proposed by 2016Ri06 from |g|g coincidence in |b-decays
234PA G 92.00 5 1.6E-3 M1 5.33 8
234PAS G LC=4.03 6$MC=0.972 14$NC=0.261 4$OC=0.0625 9$PC=0.01195 17$
234PAS G QC=0.000990 14
234PA2 G %IG=8.0E-6
234PA cG E,RI$in 2016Ri06, observed in |g|g-coin spectrum. I|g=0.0087 (17)
234PA cG $Ice(L1)=5.1 {I14}; L1/M1=3.0 {I17}. No photon was observed.
234PA G 184.8 2 1 E1 0.116116
234PAS G KC=0.0912 13$LC=0.01879 26$MC=0.00454 6$NC=0.001207 17$OC=0.000282 4$
234PAS G PC=5.04E-5 7$QC=3.01E-6 4
234PA2 G %IG=0.010 6
234PA cG RI$from 1965Fo09 and 2016Ri06. No intensity is given by 1973Go40, and
234PA2cG this transition was not observed by 1978Ch06.
234PA cG E$in 2016Ri06, observed in |g|g-coin spectrum
234PA B (13) 3 0.011 7 6.75 48 ?
234PAS B EAV=3.2 8
234PA cB $E|b=22 {I3} and I|b=1 (1973Go40)