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 22S(n)= 7157.9 keV 30S(p)= 13358.3 keV 26Q(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) 

General Comments:

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)









E(level)
(keV)
XREFJπ(level) T1/2(level)E(γ)
(keV)
I(γ)Final Levels
      0.0AB 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)
XREFJπ(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): LABEL=T1/2 or Γ

T1/2(level): Γ from R-matrix analysis in 1H(30Mg,p):IAR (2014Im02)

Back to top

Back to top

Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
      0.05/2(+) 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.
   1613.01/2+,3/2+   Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.).
   3239.31/2+,3/2+   Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.).
   3433.31/2+,3/2+   Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.).
   3623.01/2+,3/2+   XREF: d(3700).
Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.).
   4143.31/2+,3/2+   Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.).
   4563.71/2+,3/2+   Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.).
   4640.41/2+,3/2+   Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.).
   5046.51/2+,3/2+   Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.).
   5149.71/2+,3/2+   XREF: E(5164).
Jπ(level): Allowed β transitions (log ft=4.9-5.7) from 1/2+ (31Mg g.s.).
  158041/2+ 15 keV 8  Jπ(level): From R-matrix analysis in 1H(30Mg,p):IAR (2014Im02) and identification as IAR of states in 31Mg.
  158673/2+ 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.

Back to top