ADOPTED LEVELS, GAMMAS for 149La

Authors: Balraj Singh and Jun Chen |  Citation: Nucl. Data Sheets 185, 2 (2022) |  Cutoff date: 23-Aug-2022 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=6.45×103 keV 20S(n)= 5.58×103 keV 20S(p)= 9.96×103 keV 20Q(α)= -2.59×103 keV 20
Reference: 2021WA16

References:
  A  149Ba β- decay (352 MS)  B  248Cm SF decay

General Comments:

149La isotope produced through mass separation of fission fragments from 235U(n,F) E(n)=thermal (1979En02,1986ReZU,2002Sy01,2004Sy01). See also 2017Wu04, with isotope production in 9Be(238U,F) reaction, followed by half-life measurement of 149La decay.

Mass measurement using Penning-trap method: 2003SaZU

Theoretical studies: consult the NSR database at www.nndc.bnl.gov/nsr/ for one references dealing with radioactive decay, listed under ’document record’ which can be accessed through web retrieval of the ENSDF database at www.nndc.bnl.gov/ensdf/

Q-value: S(2n)=9680 200, S(2p)=22880 200, Q(β-n)=2110 200 (2021Wa16)










E(level)
(keV)
XREFJπ(level) T1/2(level)E(γ)
(keV)
I(γ)M(γ)Final Levels
     0.0AB (3/2) 1.091 s 34 
% β- = 100
% β-n = 1.41 34
     
   0+X B (7/2-)        
    45.97 8 A  (1/2,3/2,5/2)      46.0 1 
  100
M1+E2
     0.0
(3/2)
    81.5+X 3  B (11/2-)      81.5
 
(E2)
   0+X
(7/2-)
    83.00 10 A       83.0 1 
  100

     0.0
(3/2)
   164.50 18 A       81.5 2 
  100
M1,E2
    83.00

   226.03 8 A      180.1 1 
  226.0 1 
  100 5 
   87 6 


    45.97
     0.0
(1/2,3/2,5/2)
(3/2)
   280.8+X 5  B (15/2-)     199.3
 
(Q)
    81.5+X
(11/2-)
   286.30 17 A      121.8 2 
  286.3 2 
   16 4 
  100 24 


   164.50
     0.0

(3/2)
   357.32 15 A      131.3 2 
  357.3 2 
   27 5 
  100 16 


   226.03
     0.0

(3/2)
   505.7 3 A      219.4 2 
  100

   286.30

   516.53 22 A      290.5 2 
  100

   226.03

   598.3+X 6  B (19/2-)     317.5
 
(Q)
   280.8+X
(15/2-)
   843.6 5 A      617.6 5 
  100

   226.03

   893.9 3 A      607.6 2 
  100

   286.30

  1016.5+X 6  B (23/2-)     418.2
 
(Q)
   598.3+X
(19/2-)
  1510.3+X 7  B (27/2-)     493.8
 
(Q)
  1016.5+X
(23/2-)
  2051.1+X 8  B (31/2-)     540.8
 
(Q)
  1510.3+X
(27/2-)
  2606.7+X 8  B (35/2-)     555.6
 

  2051.1+X
(31/2-)

E(level): From a least-squares fit to Eγ values, assuming an uncertainty of 0.3 keV if not available

Jπ(level): ΔJ=2 high-spin band based on (7/2-) in 248Cm SF decay, also supported by a cascade of quadrupole transitions (most likely E2) from γγ(θ) data.

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Band Transitions:

E(level)
(keV)
Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 1 - Probable π3/2[541],α=-1/2
   0+X (7/2-)        
    81.5+X 3  (11/2-)        
   280.8+X 5  (15/2-)     199.3
 
(Q)
    81.5+X
(11/2-)
   598.3+X 6  (19/2-)     317.5
 
(Q)
   280.8+X
(15/2-)
  1016.5+X 6  (23/2-)     418.2
 
(Q)
   598.3+X
(19/2-)
  1510.3+X 7  (27/2-)     493.8
 
(Q)
  1016.5+X
(23/2-)
  2051.1+X 8  (31/2-)     540.8
 
(Q)
  1510.3+X
(27/2-)
  2606.7+X 8  (35/2-)     555.6
 

  2051.1+X
(31/2-)

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Additional Gamma Data:













E(level)
(keV)
Jπ(level)T1/2(level)E(γ)
(keV)
MultipolarityConversion
Coefficient
Additional Data
    45.97 (1/2,3/2,5/2)      46.0 1 M1+E223α=23 13
    81.5+X (11/2-)      81.5(E2)4.15α=4.15 6
   164.50      81.5 2 M1,E23.0α=3.0 11

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
     0.0(3/2) 1.091 s 34 
% β- = 100
% β-n = 1.41 34
XREF: B(?).
   0+X(7/2-)   E(level): Probable π3/2[541],α=-1/2.
    81.5+X(11/2-)   E(level): Probable π3/2[541],α=-1/2.
   280.8+X(15/2-)   E(level): Probable π3/2[541],α=-1/2.
   598.3+X(19/2-)   E(level): Probable π3/2[541],α=-1/2.
  1016.5+X(23/2-)   E(level): Probable π3/2[541],α=-1/2.
  1510.3+X(27/2-)   E(level): Probable π3/2[541],α=-1/2.
  2051.1+X(31/2-)   E(level): Probable π3/2[541],α=-1/2.
  2606.7+X(35/2-)   E(level): Probable π3/2[541],α=-1/2.

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Additional Gamma Comments:

E(level)E(gamma)Comments
    45.97    46.0M(γ): From conversion coefficients deduced based on I(γ+ce) intensity balance in 149Ba β- decay (2004Sy01)
    81.5+X    81.5M(γ): from ce data in 248Cm SF decay
   164.50    81.5M(γ): From conversion coefficients deduced based on I(γ+ce) intensity balance in 149Ba β- decay (2004Sy01)
   280.8+X   199.3M(γ): From γγ(θ) in 248Cm SF decay. Mult=(Q) corresponds to ΔJ=2 transition, most likely E2.
   598.3+X   317.5M(γ): From γγ(θ) in 248Cm SF decay. Mult=(Q) corresponds to ΔJ=2 transition, most likely E2.
  1016.5+X   418.2M(γ): From γγ(θ) in 248Cm SF decay. Mult=(Q) corresponds to ΔJ=2 transition, most likely E2.
  1510.3+X   493.8M(γ): From γγ(θ) in 248Cm SF decay. Mult=(Q) corresponds to ΔJ=2 transition, most likely E2.
  2051.1+X   540.8M(γ): From γγ(θ) in 248Cm SF decay. Mult=(Q) corresponds to ΔJ=2 transition, most likely E2.

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