ADOPTED LEVELS, GAMMAS for 12Be

Authors: J.H. Kelley, J.E. Purcell and C.G. Sheu |  Citation: Nucl. Physics A968, 71 (2017) |  Cutoff date: 1-Jan-2017 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=11708.4 keV 23S(n)= 3170.7 keV 19S(p)= 22939.5 keV 20Q(α)= -8956.8 keV 19
Reference: 2017WA10

References:
  A  1H(12Be,12Be),(12Be,12Be’)  B  2H(11Be,pγ)
  C  4He(8He,12Be)  D  4He(12Be,12Be’γ)
  E  7Li(12B,7Be)  F  9Be(12C,9C)
  G  9Be(13B,12Be)  H  9Be(15N,12N)
  I  9Be(18O,12BeG)  J  10Be(t,p)
  K  10Be(14N,12N)  L  12C(π-+)
  M  12C(12Be,12Be’)  N  12C(14Be,12Be)
  O  12C(14C,14O),14C(12C,14O)  P  14C(14C,16O)
  Q  TA(p,X)  R  TA(12Be,12Be’γ)
  S  197Au(12Be,G12BE)  T  208Pb(12Be,G12BE)
  U  238U(p,12Be) 








E(level)
(keV)
XREFJπ(level) T1/2(level)E(γ)
(keV)
I(γ)M(γ)Final Levels
     0AB DEF  IJKLM OPQRSTU 0+ 21.46 ms 5 
% β- = 100
% β-n = 0.50 3
     
  2109 1 AB D F  IJKL  OP RST  2+ 0.957 ps 19 
% IT = 100
  2109 1 
  100
E2
     0
0+
  2251 1  B  E   IJ    O       0+ 230 ns 8 
% IT = 100
   142 2 
  2251
   17.7
 
E2
E0
  2109
     0
2+
0+
  2715 15 AB D     J L  OP RST  1- 1.3 fs 4 
% IT = 100
  2715 2 
  100
E1
     0
0+
  4412 16 ?      G               (2-) 634 keV 60 
% n > 0
     
  4580 5 A    F   JK   OP      (2+,3-) 101 keV 17       
  5724 6 A    F H JK   OP      (4+,2+,3-) 85 keV 15       
  6275 50      F H  K                  
     7.2E3 1      F H      O       (2+)        
  8230?     F                       
     8.60E3 15 A    F                < 500 keV      
  9300       H      O       2.0 MeV 3       
    10.0E3A  D F      M         1.5 MeV 2       
    10.8E3   D F H              0+        
    11.3E3   D F    K           2+        
    11.8E3   D        MN        (0,2+) ≈ 1 MeV      
    12.1E3     F      M         (2+,4)        
    13.2E3 5 A C         MN        (4+) ≈ 1 MeV      
    14.0E3A C         M                
    14.9E3 5 A C  F H    MN        6+        
    15.5E3A C         MN        ≈ 1.5 MeV      
    16.1E3 5 A    F                6        
    17.8E3 5 A           M         6 ≈ 350 keV      
    18.6E3 5 A           M         6        
E(level)
(keV)
XREFJπ(level) T1/2(level)E(γ)
(keV)
I(γ)M(γ)Final Levels
    19.3E3 5 A      H    M O       6        
    20.9E3 5        H    M         8+        
    22.8E3A                            
    24E3?A                            
    25E3A                     ≈ 370 keV
% p > 0
     
    28E3A                     ≈ 2.7 MeV
% p > 0
     

T1/2(level): LABEL=t or Γ

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Additional Gamma Data:











E(level)
(keV)
Jπ(level)T1/2(level)E(γ)
(keV)
MultipolarityAdditional Data
  2109 2+ 0.957 ps 19 
% IT = 100
  2109 1 E2B(E2)=14.2E-4 28, B(E2)(W.u.)=8.5 17
  2251 0+ 230 ns 8 
% IT = 100
   142 2 E2B(E2)(W.u.)=4.21 44
  2715 1- 1.3 fs 4 
% IT = 100
  2715 2 E1B(E1)(W.u.)=4.9E-3 13

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
     00+ 21.46 ms 5 
% β- = 100
% β-n = 0.50 3
T=2
T1/2: From weighted average of T1/2=21.49 ms 3 (2001Be53,2002Be53), 26.1 ms 24 (1994Ke06), 21.32 ms 6 (Reeder et al., Int. Conf. on Nucl. Data for Science and Technology, May 9-13, 1994, Gatlinburg, Tennessee: see also (1991Re02)), 21.3 ms 22 (1986Cu01), 24.0 ms 10 (1984Du15), and 24.4 ms 30 (1978Al10).
E(level): T1/2: From weighted average of T1/2=21.49 ms 3 (2001Be53,2002Be53), 26.1 ms 24 (1994Ke06), 21.32 ms 6 (Reeder et al., Int. Conf. on Nucl. Data for Science and Technology, May 9-13, 1994, Gatlinburg, Tennessee: see also (1991Re02)), 21.3 ms 22 (1986Cu01), 24.0 ms 10 (1984Du15), and 24.4 ms 30 (1978Al10).
  21092+ 0.957 ps 19 
% IT = 100
T=2
T1/2: From |t=1.38 ps 20(stat) 19(syst) (2018Mo12); see also T1/2=1.73 ps 53 in (2009Im01).
E(level): T1/2: From |t=1.38 ps 20(stat) 19(syst) (2018Mo12); see also T1/2=1.73 ps 53 in (2009Im01).
  22510+ 230 ns 8 
% IT = 100
T1/2: From average of 247 ns 15 (2013Jo06) and 229 ns 8 (2007Sh34).
  27151- 1.3 fs 4 
% IT = 100
T1/2: From B(E1) given in (2000Iw03).
  4580(2+,3-) 101 keV 17  E(level): Decay mode not specified.
  5724(4+,2+,3-) 85 keV 15  E(level): Decay mode not specified.
  6275   E(level): Decay mode not specified.
     7.2E3(2+)   E(level): Decay mode not specified.
  8230   E(level): Decay mode not specified.
     8.60E3 < 500 keV E(level): Decay mode not specified.
  9300 2.0 MeV 3  E(level): Decay mode not specified.
    10.0E3 1.5 MeV 2  E(level): Decays via α+8He.
    10.8E30+   E(level): Decays via 6He+6He.
    11.3E32+   E(level): Decay mode not specified.
    11.8E3(0,2+) ≈ 1 MeV E(level): Decays via 6He+6He.
    12.1E3(2+,4)   E(level): Decays via α+8He.
    13.2E3(4+) ≈ 1 MeV E(level): Decays via α+8He and 6He+6He.
    14.0E3   E(level): Decays via α+8He and 6He+6He.
    14.9E36+   E(level): Decays via α+8He and 6He+6He.
    15.5E3 ≈ 1.5 MeV E(level): Decays via α+8He and 6He+6He.
    16.1E36   E(level): Decays via α+8He.
    17.8E36 ≈ 350 keV E(level): Decays via α+8He and 6He+6He.
    18.6E36   E(level): Decays via α+8He and 6He+6He.
    19.3E36   E(level): Decays via α+8He and 6He+6He.
    20.9E38+   E(level): Decays via α+8He and 6He+6He.
E(level)Jπ(level)T1/2(level)Comments
    22.8E3   E(level): Decays via α+8He and 6He+6He.
    24E3   E(level): Decays via α+8He and 6He+6He.

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Additional Gamma Comments:

E(level)E(gamma)Comments

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