ADOPTED LEVELS, GAMMAS for 231U

Authors: Balraj Singh, Jagdish K. Tuli, and Edgardo Browne |  Citation: Nucl. Data Sheets 185, 560 (2022) |  Cutoff date: 31-Aug-2022 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=-1820 keV 50S(n)= 5880 keV 5S(p)= 5657 keV 4Q(α)= 5576.3 keV 17
Reference: 2021WA16

References:
  A  231Np ε decay (48.8 M)  B  235Pu α decay (25.3 M)

General Comments:

1949Os01: 231U formed and identified in 231Pa(d,2n), 231Pa(α,p3n), followed by chemical separation

1950Cr28: 231U identified as parent of 231Pa

1994Br36: detailed study of ε decay of 231U to 231Pa

Theoretical studies: consult the NSR database (www.nndc.bnl.gov/nsr/) for 40 primary references, 10 for nuclear structure calculations and 30 for calculation of α-decay and cluster-decay half-lives. These references are listed in ’document’ records in this dataset, which can be accessed through on-line ENSDF database at www.nndc.bnl.gov/ensdf/

Levels: 9/2- member of configuration=ν5/2[752] (1973We08) is expected at 102 keV from rotational energy formula

Q-value: S(2n)=13547 6, S(2p)=10358 3, Q(ε)=381.6 20 (2021Wa16)










E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
     0.0AB (5/2-) 4.2 d 1 
% ε ≈ 100
% α > 0.004 1
     
   0+X? B (5/2+)        
    45.1 3 A  (7/2-)       45.1 3 S
 
[M1+E2]
     0.0
(5/2-)
   416.1 3 A       370.9 3 
   416.3 3 
  100
    2.9 6 


    45.1
     0.0
(7/2-)
(5/2-)
   421.1 4 A       376.3 4 
   420.7 4 
   61 3 
  100 10 


    45.1
     0.0
(7/2-)
(5/2-)
   481.7 4 A       436.9 4 
   481.6 5 
   47 10 
  100 19 


    45.1
     0.0
(7/2-)
(5/2-)
  1153.5 4 A       737.8 3 
  1108.1 3 
  100 6 
   44 4 


   416.1
    45.1

(7/2-)
  1268.1 4 A       786.6 3 
   851.6 5 
   26.8 14 
  100 4 


   481.7
   416.1


E(level): From 231Np ε decay, except for the tentative 40-keV level, which is from 235Pu α decay

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Additional Gamma Data:













E(level)
(keV)		Jπ(level)T1/2(level)E(γ)
(keV)		MultipolarityConversion
Coefficient		Additional Data
    45.1 (7/2-)       45.1 3 [M1+E2]33×101α=33×101 28

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
     0.0(5/2-) 4.2 d 1 
% ε ≈ 100
% α > 0.004 1
%α: from 1994Li12. Other value: %α=0.0055 (1950Cr28, unpublished data) using ion-chamber method.
E(level): %α: from 1994Li12. Other value: %α=0.0055 (1950Cr28, unpublished data) using ion-chamber method.
    45.1(7/2-)   7/2 member of configuration=ν5/2[752] (1973We08).

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