33AL 33MG B- DECAY (90.3 MS) 2006ANZW,2008TR07 25NDS 202501
33AL H TYP=FUL$AUT=Jun Chen and Balraj Singh$
33AL2 H CIT=NDS 199, 1 (2025)$CUT=30-Sep-2024$
33AL c 2006AnZW: {+33}Mg source was produced by fragmentation of 78
33AL2c MeV/nucleon {+36}S primary beam at GANIL. Fragments were separated by
33AL3c the double-achromatic LISE3 spectrometer and focused onto a telescope
33AL4c detector of silicon and plastic scintillator detectors for ion
33AL5c identification and |b detection, at the centre of TONNERRE array for
33AL6c detecting neutrons. |g rays were detected with two EXOGAM clover
33AL7c modules and a LEPS detector. Measured E|g, I|g, E(n), I(n), |b|g-coin,
33AL8c |bn-coin. Deduced levels, parent T{-1/2}, |b-decay branching ratios,
33AL9c log {Ift}, |b-delayed neutron emission probability. Comparisons with
33ALac shell-model calculations.
33AL c 2008Tr07: {+33}Mg source was produced in the reaction Be({+48}Ca,X)
33AL2c with a 140 MeV/nucleon {+48}Ca primary beam provided by NSCL at MSU.
33AL3c Fragments were separated by the A1900 fragment separator and
33AL4c transported and implanted into the double-sided silicon strip detector
33AL5c (DSSD) of the beta counting system (BCS) for detection of charged
33AL6c particles and |b particles; |g rays were detected with 16 Ge detectors
33AL7c of the Segmented Germanium Array (SeGA). Measured E|g, I|g, E|b, I|b,
33AL8c |g|g-coin, implant-|b(t). Deduced levels, J, |p, parent T{-1/2},
33AL9c |b-decay branching ratios, log {Ift}, configuration of {+33}Mg ground
33ALac state. Comparisons with Monte-Carlo shell-model (MCSM) calculations
33ALbc with SDPF-M interaction.
33AL c Others:
33AL c 2017Ha23: measured half-life at Radioactive Ion Beam Lin in LanZhou
33AL2c (RIBLL)
33AL c 2002Mo29: measured half-life at NSCL, MSU.
33AL c 1984La03, 1984Gu19: Measured |b-delayed neutrons, {+33}Mg isotope
33AL2c half-life and |bn coin, %|b{+-}n, at CERN.
33AL c {+33}Mg also decays to {+32}Al by delayed neutrons.
33AL c Based on shell-model calculations, 2008Tr07 propose 1p-1h and
33AL2c 3p-3h mixed configuration for g.s. of {+33}Mg; and 0p-0h and 2p-2h
33AL3c mixed configuration for {+33}Al g.s. with mostly 2p-2h low-lying
33AL4c excited states, which places {+33}Al within the island of inversion.
33AL c The decay scheme is as that proposed by 2006AnZW, unless otherwise
33AL2c noted. The decay scheme proposed in 2008Tr07 is different and supports
33AL3c a positive parity of {+33}Mg ground state, while a negative parity is
33AL4c adopted in Adopted Levels of {+33}Mg, assigned by 2010Yo08 based on
33AL5c measured |b-asymmetry in a NMR experiment. Moreover, the level scheme
33AL6c proposed by 2017Mu05 in {+9}Be({+34}Si,{+33}Al|g) agrees with the decay
33AL7c scheme in 2006AnZW but not that in 2008Tr07, in terms of the placements
33AL8c of their common |g rays.
33AL c The decay scheme is considered as incomplete due to a large gap (|?4.5
33AL2c MeV) between the highest observed level at E=8870 and
33AL3c Q(|b{+-})value=13460 {I7}.
33AL cB IB$From |g-ray intensity balance at each level for levels below
33AL2cB S(n)=5469 {I10}, and from 2006AnZW based on measured |b-delayed
33AL3cB neutrons for levels above S(n), unless otherwise noted. Due to
33AL4cB the incompleteness of this decay scheme, quoted values are considered
33AL5cB as approximate by the evaluators, and the same for the associated
33AL6cB log {Ift} values.
33AL cG E,RI$From 2008Tr07
33AL cL $A 2761 level from 2006AnZW based on a 2761 g.s. transition is omitted,
33AL2cL since it is most likely from {+32}Al, as pointed out by 2008Tr07
33AL cL $3264 and 4310 levels proposed in 2008Tr07 are omitted, since their
33AL2cL de-exciting transitions are placed differently by 2017Mu05 in
33AL3cL {+9}Be({+34}Si,{+33}Al|g) based on |g|g-coin, while no |g|g-coin
33AL4cL data are available in 2008Tr07 for those transitions.
33AL cL E$From E|g data in 2008Tr07 and placements of |g transitions in Adopted
33AL2cL Levels, Gammas, mostly taken from 2017Mu05 in ({+34}Si,{+33}Al|g),
33AL3cL where E|g are available, and from measured |b-delayed neutrons in
33AL4cL 2006AnZW for levels above S(n)=5469 {I10}.
33AL cL J$From the Adopted Levels
33MG P 0.0 3/2- 90.3 MS 10 13460 7
33MG cP J,T$From the Adopted Levels of {+33}Mg.
33MG cP QP$From 2021Wa16. S(n)({+33}Al)=5469 {I10} (2021Wa16)
33AL N 1.0 1.0 1.0
33AL cN NR$The absolute (per 100 decays of {+33}Mg) gamma-ray intensities
33AL2cN are given by 2008Tr07 from the total number of {+33}Mg implants and
33AL3cN measured |g-ray detector efficiencies.
33AL cN BR$%|b{+-}n=15 {I2} for the decay of {+33}Mg; see detailed comments
33AL2cN in {+33}Mg Adopted Levels.
33AL PN 4
33AL G 1466 3 1 ?
33AL cG $Placed from the 4730 level to a 3264 level in 2008Tr07, however,
33AL2cG neither this |g or the 3264 level is seen in 2006AnZW or other
33AL3cG studies like 2017Mu05. The 1647|g placed from the 3264 level in
33AL4cG 2008Tr07 is placed from the 1647 level in both 2006AnZW and 2017Mu05,
33AL5cG which is adopted in Adopted Levels, Gammas. Since this |g is not shown
33AL6cG in the |g spectrum and not seen in |g|g-coin in 2008Tr07, the
33AL7cG evaluators consider this |g questionable.
33AL L 0 (5/2)+ 41.5 MS 1
33AL cL T$from the Adopted Levels
33AL B 15 6 5.6
33ALS B EAV=6425.9 34
33AL cB IB,LOGFT$feeding to the g.s. is deduced from 100-|SI(|g to
33AL2cB g.s.)-%|b{+-}n, and considered as an upper limit due to possible
33AL3cB unobserved weak transitions from higher-energy levels including
33AL4cB unobserved levels in the large gap (|?4.5 MeV) between the highest
33AL5cB observed level and Q(|b{+-})value. Quoted log {Ift} should be
33AL6cB considered as a lower limit.
33AL L 1618 (5/2)+
33AL B 12 2 5.5
33ALS B EAV=5630.5
33AL G 1618 16 2
33AL L 1647 (5/2)+
33AL B 7 1 5.7
33ALS B EAV=5616.3
33AL G 1647 7 1
33AL cG E$placement from 2006AnZW and 2017Mu05; placed from a 3264 level in
33AL2cG 2008Tr07
33AL L 1838 (1/2+,3/2,5/2)
33AL B 6 2 5.7
33ALS B EAV=5522.4
33AL cB $I|b=6 {I2}, log| {Ift}=5.69 {I15} in figure 3 of 2008Tr07
33AL G 1838 9 2
33AL L 2096 1/2+
33AL cL E$level from re-placement of 2096|g in 2008Tr07, based on the
33AL2cL placement in 2017Mu05; this level is also reported in 2006AnZW
33AL B 4 2 5.8
33ALS B EAV=5395.6
33AL G 2096 9 2
33AL cG E$placement from 2006AnZW and 2017Mu05; placed from a 3714 level in
33AL2cG 2008Tr07. It could be a doublet of 2080|g from 3704 level and 2101|g
33AL3cG from 2101 level in 2017Mu05
33AL L 2365 (1/2+,3/2,5/2)
33AL cL E$level proposed in 2008Tr07; not reported in 2006AnZW. A 2366 level
33AL2cL is tentatively proposed in 2017Mu05 based on a 2366|g.
33AL B 7 1 5.5
33ALS B EAV=5263.3
33AL G 2365 7 1
33AL L 2664 (1/2+,3/2,5/2)
33AL cL E$level from re-placement of 1046|g in 2008Tr07, based on the
33AL2cL placement in 2017Mu05, which is adopted in Adopted Levels, Gammas
33AL B 4 1 5.7
33ALS B EAV=5116.3
33AL G 1046 4 1
33AL cG E$placement from 2017Mu05; placed from a 4310 level in 2008Tr07
33AL L 2692 (1/2+,3/2,5/2+)
33AL cL E$level from re-placement of 596|g and 2692|g in 2008Tr07, based on
33AL2cL placements in 2017Mu05
33AL B 9 2 5.4
33ALS B EAV=5102.6
33AL G 596 5 1
33AL cG E$placement from 2017Mu05; placed from a 4310 level in 2008Tr07
33AL G 2692 4 2
33AL cG E$placement by the evaluators based on placement of 596|g; placed from
33AL2cG a 4310 level in 2008Tr07; not reported in 2006AnZW and 2017Mu05
33AL cG RI$ not listed by 2008Tr07, deduced by the evaluators from
33AL2cG intensity balance=13 {I2} at 4310 level quoted in FIG.3 of 2008Tr07
33AL L 3714 (3/2-,5/2-) ?
33AL cL E$reported only in 2008Tr07, proposed based on very weak
33AL2cL 1618|g-2096|g-coin. It could be the same level as the 3702 level in
33AL3cL ({+34}Si,{+33}Al|g) dataset (3704 in 2017Mu05)
33AL B 8 2 5.2
33ALS B EAV=4600.3
33AL G 2096 ?
33AL cG E$placement from 2008Tr07. It could be a doublet of 2080|g from 3704
33AL2cG level and 2101|g from 2101 level in 2017Mu05
33AL G 3714 8 2 ?
33AL cG E$reported only in 2008Tr07
33AL L 4730 (3/2-,5/2-)
33AL B 13 3 4.8
33ALS B EAV=4101
33AL cB IB$other: 18 {I2} in 2006AnZW
33AL G 2892 3 1
33AL cG E$other: 2897 (2006AnZW)
33AL G 4730 10 3
33AL cG E$other: 4735 (2006AnZW)
33AL L 5930 (1/2-,3/2-,5/2-)
33AL B 1.9 2 5.3
33ALS B EAV=3511.8
33AL L 5980 (1/2-,3/2-,5/2-)
33AL B 3.3 3 5.1
33ALS B EAV=3487.3
33AL L 6820 (1/2-,3/2-,5/2-)
33AL B 0.71 4 5.5
33ALS B EAV=3075.4
33AL L 7250 (1/2-,3/2-,5/2-)
33AL B 1.32 4 5.1
33ALS B EAV=2864.7
33AL L 7470 (1/2-,3/2-,5/2-)
33AL B 0.90 3 5.2
33ALS B EAV=2757
33AL L 8870 (1/2-,3/2-,5/2-)
33AL B 1.96 5 4.3
33ALS B EAV=2073.6
33AL L 5469+X R
33AL cL E$x<7991 {I8} from Q(|b{+-})({+33}Mg)-S(n)({+33}Al), where
33AL2cL Q(|b{+-})=13460 {I7} and S(n)=5469 {I10} from 2021Wa16. This represents
33AL3cL a range of unobserved levels above 8870 level that subsequently decay
33AL4cL to {+32}Al and {+31}Al via one- and two-neutron emissions, respectively
33AL B 4.9 21
33AL cB IB$from adopted total %|b{+-}n=15 {I2} for the decay of
33AL2cB {+33}Mg g.s. minus a sum of 10.1 {I4} for measured |b{+-}n feedings to
33AL3cB levels up to 8870 from 2006AnZW.