ADOPTED LEVELS, GAMMAS for 251Es

Author: C. Morse |  Citation: Nucl. Data Sheets 189, 111 (2023) |  Cutoff date: 23-Sep-2022 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=-1447 keV 15S(n)= 6785 keV SYS(p)= 3948 keV 5Q(α)= 6597.1 keV 10
Reference: 2021Wa16

References:
  A  251Fm ε decay  B  255Md α decay
  C  250Cf(α,t) 








E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
     0ABC 3/2- 33 h 1 
% α = 0.5 1
% ε = 99.5 1
     
     8.34 23 AB  (7/2)+        
    31.70 20 ABC 5/2-        
    55.85 23 AB  (9/2)+       47.48 6 
  100
M1+E2
     8.34
(7/2)+
    76.1 3 ABC 7/2-        
   114.08 24 A   (11/2+)        
   182.6 3 A C (13/2+)        
   263.0 4 A   (15/2+)        
   411 2   C (1/2-)        
   452 2   C (5/2-)        
   461.40 22 AB  7/2-      385.3 2 
   405.55 9 
   429.7 1 
   453.06 9 
    2.1 2 
   68.2 34 
    5.7 5 
  100
(M1+E2)
E1+M2
(M1+E2)
E1+M2
    76.1
    55.85
    31.70
     8.34
7/2-
(9/2)+
5/2-
(7/2)+
   523 2  BC (9/2-)        
   548 2   C (7/2-)        
   548 2   C (9/2-)        
   661 3   C (1/2+)        
   777.94 24 A   (9/2)+      664.0 3 
   722.1 2 
   769.6 1 
    4.3 8 
   21 2 
  100
(M1+E2)
M1+E2
M1
   114.08
    55.85
     8.34
(11/2+)
(9/2)+
(7/2)+
   889.10 24 A   (11/2)+      706.3 2 
   775.0 1 
   833.3 1 
   880.8 1 
    1.1 1 
   ≈3.9
   29 2 
  100
(M1+E2)
(M1+E2)
M1+E2
E2
   182.6
   114.08
    55.85
     8.34
(13/2+)
(11/2+)
(9/2)+
(7/2)+
   942 4   C (13/2)+        
   957.52 24 A C (13/2)+      694.5 3 
   775.0 1 
   843.4 1 
   901.6 1 
   12 2 
  ≈32
   92 8 
  100
(M1+E2)
(M1+E2)
M1+E2
E2
   263.0
   182.6
   114.08
    55.85
(15/2+)
(13/2+)
(11/2+)
(9/2)+
E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
  1238.95 24 A   (11/2)+      281.4 1 
   349.9 1 
   461.0 1 
  1056.2 4 
  1124.9 2 
  1183.0 2 
  1230.6 2 
    8.6 6 
  100
   11 1 
    0.7 1 
    3.3 4 
    8.8 6 
   16 1 
M1
M1
(M1+E2)
(M1+E2)
(M1+E2)
(M1+E2)
E2
   957.52
   889.10
   777.94
   182.6
   114.08
    55.85
     8.34
(13/2)+
(11/2)+
(9/2)+
(13/2+)
(11/2+)
(9/2)+
(7/2)+
  1264.94 24 A   (11/2)+      307.4 1 
   375.8 1 
   487.1 2 
  1151.0 2 
  1209.1 2 
  1256.6 2 
    9.7 8 
  100
    3.0 5 
    4.1 5 
    9.5 8 
   18 1 
(M1+E2)
M1
(M1+E2)
(M1+E2)
(M1+E2)
E2
   957.52
   889.10
   777.94
   114.08
    55.85
     8.34
(13/2)+
(11/2)+
(9/2)+
(11/2+)
(9/2)+
(7/2)+
  1301.4 3 A   (7/2+,9/2,11/2)     1245.6 4 
  1293.0 3 
   16 2 
  100


    55.85
     8.34
(9/2)+
(7/2)+
  1307.1 3 A   (7/2+,9/2,11/2+)     1193.0 2 
  1251.2 2 
  1298.8 3 
   21 2 
   45 4 
  100



   114.08
    55.85
     8.34
(11/2+)
(9/2)+
(7/2)+
  1357.0 3 A   (7/2+,9/2,11/2+)     1242.8 4 
  1301.2 3 
  1348.6 3 
   52 5 
  100 1 
   33 3 



   114.08
    55.85
     8.34
(11/2+)
(9/2)+
(7/2)+

E(level): Determined by least-squares fit to the γ-ray energies, and assuming that the 5/2- member of the π3/2-[521] band decays to the ground state by a 31.7 2 keV transition (c.f. 251Fm ε decay), unless otherwise noted.

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Band Transitions:

E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 1 - π3/2-[521]
     0 3/2- 33 h 1 
% α = 0.5 1
% ε = 99.5 1
     
    31.70 20  5/2-        
    76.1 3  7/2-        
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 2 - π7/2+[633]
     8.34 23  (7/2)+        
    55.85 23  (9/2)+        
   114.08 24  (11/2+)        
   182.6 3  (13/2+)     
   263.0 4  (15/2+)        
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 3 - π1/2-[521]
   411 2  (1/2-)        
   452 2  (5/2-)        
   548 2  (7/2-)        
   548 2  (9/2-)     
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 4 - π7/2-[514]
   461.40 22  7/2-        
   523 2  (9/2-)        
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 5 - |[π7/2+[633]~#2+|]11/2+ γ-vibrational band
   889.10 24  (11/2)+        
   957.52 24  (13/2)+        
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 6 - π9/2+[624]
   777.94 24  (9/2)+        
   942 4  (13/2)+        

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Additional Gamma Data:















E(level)
(keV)		Jπ(level)T1/2(level)E(γ)
(keV)		MultipolarityMixing
Ratio		Conversion
Coefficient		Additional Data
    55.85 (9/2)+       47.48 6 M1+E20.243 +25-27125α=125 9, α(L)=92 7, α(M)=24.1 18, α(N)=6.7 5, α(O)=1.73 13, α(P)=0.311 20, α(Q)=0.01213 20
   461.40 7/2-      385.3 2 (M1+E2) 0.54α=0.54 40, α(K)=0.39 34, α(L)=0.107 48, α(M)=0.027 11, α(N)=0.0076 30, α(O)=0.00197 81, α(P)=3.7×10-4 17, α(Q)=1.7E-5 14
7/2-      405.55 9 E1+M20.179 90.091α=0.091 7, α(K)=0.066 5, α(L)=0.0187 15, α(M)=0.0048 4, α(N)=0.00136 11, α(O)=0.00035 3, α(P)=6.7×10-5 6, α(Q)=3.5E-6 3
7/2-      429.7 1 (M1+E2) 0.40α=0.40 30, α(K)=0.29 25, α(L)=0.078 38, α(M)=0.0196 86, α(N)=0.0055 24, α(O)=0.00142 64, α(P)=2.7×10-4 13, α(Q)=1.3E-5 10
7/2-      453.06 9 E1+M20.236 +17-180.100α=0.100 12, α(K)=0.072 8, α(L)=0.0204 25, α(M)=0.0053 7, α(N)=0.00147 18, α(O)=0.00039 5, α(P)=7.3×10-5 9, α(Q)=3.9E-6 5
   777.94 (9/2)+      664.0 3 (M1+E2) 0.125α=0.125 88, α(K)=0.095 72, α(L)=0.023 13, α(M)=0.0056 30, α(N)=0.00157 82, α(O)=4.1×10-4 22, α(P)=7.8E-5 43, α(Q)=4.0E-6 29
(9/2)+      722.1 2 M1+E20.50 +28-350.142α=0.142 25, α(K)=0.110 21, α(L)=0.024 4, α(M)=0.0059 9, α(N)=0.00163 24, α(O)=0.00043 7, α(P)=8.2×10-5 13, α(Q)=4.6E-6 9
(9/2)+      769.6 1 M1 0.1429α=0.1429, α(K)=0.1117 16, α(L)=0.0234 4, α(M)=0.00573 8, α(N)=0.001592 23, α(O)=0.000417 6, α(P)=8.07×10-5 12, α(Q)=4.60E-6 7
   889.10 (11/2)+      706.3 2 (M1+E2) 0.106α=0.106 74, α(K)=0.081 60, α(L)=0.019 11, α(M)=0.0047 25, α(N)=0.00132 69, α(O)=3.4×10-4 19, α(P)=6.6E-5 37, α(Q)=3.4E-6 25
(11/2)+      775.0 1 (M1+E2) 0.084α=0.084 57, α(K)=0.064 46, α(L)=0.0148 82, α(M)=0.0037 20, α(N)=1.02×10-3 54, α(O)=2.7E-4 15, α(P)=5.1E-5 29, α(Q)=2.7E-6 19
(11/2)+      833.3 1 M1+E22.21 +40-280.039α=0.039 4, α(K)=0.028 4, α(L)=0.0078 6, α(M)=0.00197 14, α(N)=0.00055 4, α(O)=0.000142 10, α(P)=2.66×10-5 20, α(Q)=1.21E-6 13
(11/2)+      880.8 1 E2 0.0209α=0.0209, α(K)=0.01447 21, α(L)=0.00476 7, α(M)=0.001231 18, α(N)=0.000344 5, α(O)=8.86×10-5 13, α(P)=1.627E-5 23, α(Q)=6.28E-7 9
   957.52 (13/2)+      694.5 3 (M1+E2) 0.111α=0.111 78, α(K)=0.084 63, α(L)=0.020 11, α(M)=0.0050 26, α(N)=0.00138 73, α(O)=3.6×10-4 19, α(P)=6.9E-5 38, α(Q)=3.5E-6 26
(13/2)+      775.0 1 (M1+E2) 0.084α=0.084 57, α(K)=0.064 46, α(L)=0.0148 82, α(M)=0.0037 20, α(N)=1.02×10-3 54, α(O)=2.7E-4 15, α(P)=5.1E-5 29, α(Q)=2.7E-6 19
(13/2)+      843.4 1 M1+E20.72 +22-200.081α=0.081 12, α(K)=0.063 10, α(L)=0.0138 17, α(M)=0.0034 4, α(N)=0.00095 11, α(O)=0.00025 3, α(P)=4.8×10-5 6, α(Q)=2.6E-6 4
(13/2)+      901.6 1 E2 0.0200α=0.0200, α(K)=0.01392 20, α(L)=0.00449 7, α(M)=0.001158 17, α(N)=0.000323 5, α(O)=8.34×10-5 12, α(P)=1.533E-5 22, α(Q)=6.00E-7 9
  1238.95 (11/2)+      281.4 1 M1 2.24α=2.24, α(K)=1.741 25, α(L)=0.371 6, α(M)=0.0914 13, α(N)=0.0254 4, α(O)=0.00666 10, α(P)=0.001288 18, α(Q)=7.36×10-5 11
(11/2)+      349.9 1 M1 1.223α=1.223, α(K)=0.953 14, α(L)=0.202 3, α(M)=0.0498 7, α(N)=0.01384 20, α(O)=0.00363 5, α(P)=0.000702 10, α(Q)=4.00×10-5 6
(11/2)+      461.0 1 (M1+E2) 0.33α=0.33 25, α(K)=0.24 21, α(L)=0.063 32, α(M)=0.0160 73, α(N)=0.0044 21, α(O)=0.00116 54, α(P)=2.2×10-4 11, α(Q)=1.05E-5 82
(11/2)+     1056.2 4 (M1+E2) 0.038α=0.038 23, α(K)=0.029 19, α(L)=0.0065 35, α(M)=0.00160 83, α(N)=4.4×10-4 23, α(O)=1.16E-4 61, α(P)=2.2E-5 12, α(Q)=1.20E-6 76
(11/2)+     1124.9 2 (M1+E2) 0.032α=0.032 19, α(K)=0.025 16, α(L)=0.0055 29, α(M)=0.00135 69, α(N)=3.8×10-4 19, α(O)=9.8E-5 51, α(P)=1.89E-5 99, α(Q)=1.02E-6 63
(11/2)+     1183.0 2 (M1+E2) 0.028α=0.028 17, α(K)=0.022 13, α(L)=0.0048 25, α(M)=0.00119 60, α(N)=3.3×10-4 17, α(O)=8.6E-5 44, α(P)=1.65E-5 86, α(Q)=9.0E-7 54
(11/2)+     1230.6 2 E2 0.01111α=0.01111, α(K)=0.00823 12, α(L)=0.00214 3, α(M)=0.000539 8, α(N)=0.0001502 21, α(O)=3.89×10-5 6, α(P)=7.29E-6 11, α(Q)=3.34E-7 5
  1264.94 (11/2)+      307.4 1 (M1+E2) 1.01α=1.01 74, α(K)=0.72 65, α(L)=0.214 77, α(M)=0.055 17, α(N)=0.0153 46, α(O)=0.0040 13, α(P)=7.3×10-4 28, α(Q)=3.2E-5 26
(11/2)+      375.8 1 M1 1.005α=1.005, α(K)=0.783 11, α(L)=0.1661 24, α(M)=0.0408 6, α(N)=0.01136 16, α(O)=0.00297 5, α(P)=0.000575 8, α(Q)=3.28×10-5 5
(11/2)+      487.1 2 (M1+E2) 0.28α=0.28 21, α(K)=0.21 18, α(L)=0.054 28, α(M)=0.0136 64, α(N)=0.0038 18, α(O)=9.8×10-4 47, α(P)=1.86E-4 96, α(Q)=9.1E-6 70
(11/2)+     1151.0 2 (M1+E2) 0.030α=0.030 18, α(K)=0.023 15, α(L)=0.0052 27, α(M)=0.00127 65, α(N)=3.5×10-4 18, α(O)=9.3E-5 47, α(P)=1.78E-5 93, α(Q)=9.6E-7 59
(11/2)+     1209.1 2 (M1+E2) 0.027α=0.027 16, α(K)=0.021 13, α(L)=0.0045 23, α(M)=0.00112 56, α(N)=3.1×10-4 16, α(O)=8.1E-5 41, α(P)=1.56E-5 81, α(Q)=8.5E-7 51
(11/2)+     1256.6 2 E2 0.01069α=0.01069, α(K)=0.00794 12, α(L)=0.00204 3, α(M)=0.000514 8, α(N)=0.0001431 20, α(O)=3.71×10-5 6, α(P)=6.96E-6 10, α(Q)=3.21E-7 5
E(level)
(keV)		Jπ(level)T1/2(level)E(γ)
(keV)		MultipolarityMixing
Ratio		Conversion
Coefficient		Additional Data

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
     03/2- 33 h 1 
% α = 0.5 1
% ε = 99.5 1
CONF=|p3/2-[521] (1978Ah02)
E(level): π3/2-[521].
     8.34(7/2)+   CONF=|p7/2+[633]
E(level): π7/2+[633].
    31.705/2-   E(level): π3/2-[521].
    55.85(9/2)+   E(level): π7/2+[633].
    76.17/2-   E(level): π3/2-[521].
   114.08(11/2+)   E(level): π7/2+[633].
   182.6(13/2+)   E(level): π7/2+[633].
   263.0(15/2+)   E(level): π7/2+[633].
   411(1/2-)   CONF=|p1/2-[521]
E(level): π1/2-[521]. From 250Cf(α,t).
   452(5/2-)   E(level): π1/2-[521]. From 250Cf(α,t).
   461.407/2-   CONF=7/2-[514]
E(level): π7/2-[514].
   523(9/2-)   E(level): π7/2-[514]. From 250Cf(α,t).
   548(7/2-)   E(level): π1/2-[521]. From 250Cf(α,t).
   548(9/2-)   E(level): π1/2-[521]. From 250Cf(α,t).
   661(1/2+)   CONF=|p1/2+[400]
E(level): From 250Cf(α,t).
   777.94(9/2)+   CONF=|p9/2+[624]
E(level): π9/2+[624].
   889.10(11/2)+   CONF=|[|p7/2+[633]~#2{++}|]11/2+
E(level): |[π7/2+[633]~#2+|]11/2+ γ-vibrational band.
   942(13/2)+   E(level): π9/2+[624]. From 250Cf(α,t).
   957.52(13/2)+   E(level): |[π7/2+[633]~#2+|]11/2+ γ-vibrational band.
  1264.94(11/2)+   Interpreted as a three-quasiparticle state, but a configuration could not be definitively assigned. See 251Fm ε decay.
E(level): Interpreted as a three-quasiparticle state, but a configuration could not be definitively assigned. See 251Fm ε decay.

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Additional Gamma Comments:

E(level)E(gamma)Comments
   461.40   405.55E(γ): Weighted average of 405.6 1 keV (1978Ah02), 405.5 3 keV (2000Ah02), and 405.2 3 keV (2005He27).
   453.06E(γ): Weighted average of 453.1 1 keV (1978Ah02), 453.0 3 keV (2000Ah02), and 452.8 3 keV (2005He27).

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