ADOPTED LEVELS, GAMMAS for 31Al
Authors: Jun Chen and Balraj Singh | Citation: Nucl. Data Sheets 184, 29 (2022) | Cutoff date: 24-Jun-2022
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=7998.3 keV 22 | S(n)= 7157.9 keV 30 | S(p)= 13358.3 keV 26 | Q(α)= -11858 keV 4 | ||
| Reference: 2021WA16 |
| References: | |||
| A | 31Mg β- decay (270 MS) | B | 32Mg β-n decay (80.4 MS) |
| C | 1H(30Mg,p):IAR | D | 15N(18O,2p) |
| E | 30Si(18O,17F) | ||
| E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | Final Levels | |
| 0.0 | AB DE | 5/2(+) | 644 ms 25 % β- = 100 % β-n < 1.6 | ||||
| 946.7 4 | A E | 1/2(+),3/2 | 946.7 5 | 100 | 0.0 | 5/2(+) | |
| 1613.0 3 | A E | 1/2+,3/2+ | 665.9 7 1612.8 4 | 31.4 20 100 | 946.7 0.0 | 1/2(+),3/2 5/2(+) | |
| 2.09E+3 11 | D | ||||||
| 2676 28 | E | ||||||
| 3239.3 5 | A | 1/2+,3/2+ | 1626.2 5 2291.7 14 | 100.0 27 1.7 4 | 1613.0 946.7 | 1/2+,3/2+ 1/2(+),3/2 | |
| 3433.3 5 | A | 1/2+,3/2+ | 1820.0 8 2487.4 12 3432.8 8 | 100 18 37 6 90 24 | 1613.0 946.7 0.0 | 1/2+,3/2+ 1/2(+),3/2 5/2(+) | |
| 3623.0 6 | A D | 1/2+,3/2+ | 2675.8 9 3623.0 8 | 42 5 100 9 | 946.7 0.0 | 1/2(+),3/2 5/2(+) | |
| 4143.3 4 | A | 1/2+,3/2+ | 903.8 8 2529.7 9 3196.6 10 4143.2 6 | 40 6 70 7 100 11 8.6 31 | 3239.3 1613.0 946.7 0.0 | 1/2+,3/2+ 1/2+,3/2+ 1/2(+),3/2 5/2(+) | |
| 4320 90 | D | ||||||
| 4563.7 5 | A | 1/2+,3/2+ | 2949.4 10 3617.7 12 4563.5 7 | 100 10 33 9 14 5 | 1613.0 946.7 0.0 | 1/2+,3/2+ 1/2(+),3/2 5/2(+) | |
| 4640.4 11 | A | 1/2+,3/2+ | 3693.0 19 4640.3 13 | 100 28 22 8 | 946.7 0.0 | 1/2(+),3/2 5/2(+) | |
| 4809.2 12 ? | A D | 4808.8 12 ? | 100 | 0.0 | 5/2(+) | ||
| 5046.5 14 | A | 1/2+,3/2+ | 3433.3 14 | 100 | 1613.0 | 1/2+,3/2+ | |
| 5149.7 11 | A E | 1/2+,3/2+ | 4202.7 10 | 100 | 946.7 | 1/2(+),3/2 | |
| 5729 24 | E | ||||||
| 6480 35 | E | ||||||
| E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | Final Levels | |
| 15804 5 | C | 1/2+ | 15 keV 8 | ||||
| 15867 3 | C | 3/2+ | 1.3 keV 13 | ||||
| 16026 4 | C | (3/2)- | 109 keV 2 | ||||
E(level): From a least-squares fit to γ-ray energies for levels connected with γ transitions and from particle-transfer reactions for others, unless otherwise noted.
T1/2(level): Γ from R-matrix analysis in 1H(30Mg,p):IAR (2014Im02)
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0.0 | 5/2(+) | 644 ms 25 % β- = 100 % β-n < 1.6 | μ=+3.827 5 (2021He04,2007Ue02,2006Hi18), Q=+0.1340 16 (2009De25,2021He04) Measured (small) quadrupole moment of the ground state (2021He04,2016He09,2009De25,2009Na03) suggests that 31Al lies outside the "island of inversion " with a dominant sd-shell configuration, and with a possible small admixture of 2p-2h neutron states. E(level): Measured (small) quadrupole moment of the ground state (2021He04,2016He09,2009De25,2009Na03) suggests that 31Al lies outside the "island of inversion " with a dominant sd-shell configuration, and with a possible small admixture of 2p-2h neutron states. |
| 1613.0 | 1/2+,3/2+ | Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.). | |
| 3239.3 | 1/2+,3/2+ | Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.). | |
| 3433.3 | 1/2+,3/2+ | Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.). | |
| 3623.0 | 1/2+,3/2+ | XREF: d(3700). Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.). | |
| 4143.3 | 1/2+,3/2+ | Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.). | |
| 4563.7 | 1/2+,3/2+ | Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.). | |
| 4640.4 | 1/2+,3/2+ | Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.). | |
| 5046.5 | 1/2+,3/2+ | Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.). | |
| 5149.7 | 1/2+,3/2+ | XREF: E(5164). Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.). | |
| 15804 | 1/2+ | 15 keV 8 | Jπ(level): From R-matrix analysis in 1H(30Mg,p):IAR (2014Im02) and identification as IAR of states in 31Mg. |
| 15867 | 3/2+ | 1.3 keV 13 | Jπ(level): From R-matrix analysis in 1H(30Mg,p):IAR (2014Im02) and identification as IAR of states in 31Mg. |
| 16026 | (3/2)- | 109 keV 2 | Jπ(level): From R-matrix analysis in 1H(30Mg,p):IAR (2014Im02) and identification as IAR of states in 31Mg. |
This nucleus is at the edge of a small set of nuclei belonging to the "island of inversion " where the ground state is deformed from a spherical shell, investigations in 2005Ma86 show that it does not fall within this group
Mass measurements: 2015Kw01
Other measurements:
2021He04: measured hyperfine spectra using the COLLAPS collinear laser spectroscopy beam line at ISOLDE-CERN. Deduced magnetic dipole and electric quadrupole moments.
2016He09: measured β-detected nuclear quadrupole resonance (β-NQR) spectra using the β-NRM/NQR setup at LISE-GANIL. Deduced electric quadrupole moment.
2012Kw02: production cross section measurement in fragmentation of 40Ar beam at 140 MeV/nucleon with 9Be, Ni and 181Ta targets by time-of-flight and energy loss measurements at NSCL facility
2012Zh06: 9Be(40Ar,X) E=57 MeV/nucleon, measured fragment yield, momentum distributions at HIRFL facility; deduced target dependence on production cross section
2009De25: measured electric quadrupole moment using β-NQR method with fragmentation-induced spin-polarized beam at LISE-GANIL facility
Theoretical calculations: 24 primary references for structure and three for decay characteristics retrieved from the NSR database (www.nndc.bnl.gov/nsr/) are listed under ’document records’.
Q-value: S(2n)=12885.6 23, S(2p)=32209 8, Q(β-n)=1410.9 22 (2021Wa16)