ADOPTED LEVELS, GAMMAS for 220Fr

Authors: J.Chen, M.S. Basunia P.Dimitriou, Et Al., |  Citation: Nucl. Data Sheets 212, 18 (2026) |  Cutoff date: 31-Mar-2026 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=1210 keV 8S(n)= 5206 keV 8S(p)= 4636 keV 4Q(α)= 6800.7 keV 19
Reference: 2021WA16

References:
  A  224Ac α decay (2.78 H) 

General Comments:

Calculations, compilations:

1994So16: level structure, odd-odd actinides

1990Mo11: n-p interaction energy

1988Sh01: g.s. Jπ with octupole deformation

1986Po06: spontaneous emission of heavy ions

Levels: The level scheme and all information on excited levels come from 224Ac α decay.

Gammas: All γ-ray data are from 224Ac α decay

Q-value: S(2n)=11720 6, S(2p)=11196 12, Q(ε)=870 4 (2021Wa16)










E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
    0.0A 1+ 27.4 s 3 
% β- = 0.35 5
% α = 99.65 5
     
    6.92 6 A (3)+       6.9S
 

    0.0
1+
   12.37 5 A 2+      12.4S
 

    0.0
1+
   19.89 10 A (4)+      13.0S
 

    6.92
(3)+
   48.38 4 A 2+      35.9 1 
   41.5 1 
   48.40 5 
     5 3 
     6 2 
   100 8 


M1
   12.37
    6.92
    0.0
2+
(3)+
1+
   55.83 13 A (5+)      35.9 1 
   100

   19.89
(4)+
   72.99 6 A (3)+      24.6
   53.1 1 
   60.67 5 
   66.0 1 
   72.9 1 
   ≈22
    22 4 
   100 4 
    50 9 
    11 4 


M1

(E2)
   48.38
   19.89
   12.37
    6.92
    0.0
2+
(4)+
2+
(3)+
1+
  127.31 11 A (4+)      54.3 1 
 
(M1)
   72.99
(3)+
  140.72 6 A 1-      92.34 5 
  128.4 3 
  140.7 1 
    14.6 14 
    23 6 
   100 8 

E1
E1
   48.38
   12.37
    0.0
2+
2+
1+
  156.82 4 A 2-      16.1S
   83.9 2 
  108.43 5 
  144.44 5 
  149.90 5 
  156.82 5 
 
    22.0 12 
    13.0 12 
    27.8 25 
    15.4 25 
   100 6 

E1
E1
E1
E1
E1
  140.72
   72.99
   48.38
   12.37
    6.92
    0.0
1-
(3)+
2+
2+
(3)+
1+
  177.18 8 A (3)-      20.4S
   49.8 2 
  104.4 2 
  128.9 3 
  164.8 1 
 
     8 2 
    26 6 
    72 20 
   100 20 




E1
  156.82
  127.31
   72.99
   48.38
   12.37
2-
(4+)
(3)+
2+
2+
E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
  200.21 15 A (5+)      72.9 1 
   100

  127.31
(4+)
  214.43 9 A (4)-      37.3 1 
  141.4 1 
  158.5 2 
  194.5 3 
  207.6 2 
     5.7 10 
   100 19 
    15 4 
     6.6 19 
    34 9 



E1
E1
  177.18
   72.99
   55.83
   19.89
    6.92
(3)-
(3)+
(5+)
(4)+
(3)+
  246.8 10 A        
  257.0 15 A        
  273.64 11 A 1+     225.3 2 
  261.3 2 
  273.7 4 
    17 5 
   100 8 
     5.8 16 
M1
M1
M1
   48.38
   12.37
    0.0
2+
2+
1+
  276.02 20 A     263.1 5 ?
 

   12.37
2+
  290.8 3 A (5-)     163.3 5 
  271.5 4 
   ≈50
   100 30 


  127.31
   19.89
(4+)
(4)+
  299.91 15 A (1)+     251.6 3 
  287.6 5 
  300.0 3 
   100 27 
    27 12 
    65 15 
M1

(M1)
   48.38
   12.37
    0.0
2+
2+
1+
  306.9 15 A        
  314.8 4 A     114.7 5 
  258.8 5 
   100 60 
  ≈100


  200.21
   55.83
(5+)
(5+)
  340.25 12 A (0)-      40.4 3 
   66.6 1 
  199.5 2 
  340.3 3 
     8 3 
   100 8 
    50 17 
     8 3 
(E1)
E1
M1

  299.91
  273.64
  140.72
    0.0
(1)+
1+
1-
1+
  347.9 4 A     328.0 3 
   100

   19.89
(4)+
  355.13 19 A (0-,2-)      55.3 2 
   79.10 5 
   81.5 3 
  228?
    14 4 
   100 11 
    75 7 
 
(E1)

(E1)

  299.91
  276.02
  273.64
  127.31
(1)+

1+
(4+)
  361.0 4 A      87.4 3 
 

  273.64
1+
E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
  364.16 23 A 3+,4-      73.6 3 
  186.8 3 
  357.0 5 
   100 50 
   100 33 
   ≈50



  290.8
  177.18
    6.92
(5-)
(3)-
(3)+
  376.49 20 A (2-)     103.1 4 
  328.0 3 
  364.1 3 
   ≈19
    33 14 
   100 14 



  273.64
   48.38
   12.37
1+
2+
2+
  380.1 10 A        
  414.6 20 A        
  442.2 15 A        
  452.4 11 A      97.3?
 

  355.13
(0-,2-)
  479.6 20 A        
  501.1 4 A      48.6?
  201.1 4 
  227.7 5 
 
   100 50 
   100 33 



  452.4
  299.91
  273.64

(1)+
1+
  511.1 10 A     491.2
 

   19.89
(4)+
  579.9 20 A        

E(level): From a least-squares fit to γ-ray energies, unless otherwise noted

Jπ(level): Levels without spin assignments are all deduced from α decay with π=unnatural; therefore, all have Jπ=0-,1+,2-,3+,4- etc.

M(γ): Supported by conversion-electron data in 1992Li31 and 1973ChZH.

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Band Transitions:

E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 1 - Kπ=1+ g.s. rotational band
    0.0 1+ 27.4 s 3 
% β- = 0.35 5
% α = 99.65 5
     
   48.38 4  2+      35.9 1 
   41.5 1 
   48.40 5 
     5 3 
     6 2 
   100 8 


M1
   12.37
    6.92
    0.0
2+
(3)+
1+
   72.99 6  (3)+      24.6
   53.1 1 
   60.67 5 
   66.0 1 
   72.9 1 
   ≈22
    22 4 
   100 4 
    50 9 
    11 4 


M1

(E2)
   48.38
   19.89
   12.37
    6.92
    0.0
2+
(4)+
2+
(3)+
1+
  127.31 11  (4+)      54.3 1 
 
(M1)
   72.99
(3)+
  200.21 15  (5+)      72.9 1 
   100

  127.31
(4+)
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 2 - Kπ=1- band
  140.72 6  1-        
  156.82 4  2-      16.1S
   83.9 2 
  108.43 5 
  144.44 5 
  149.90 5 
  156.82 5 
 
    22.0 12 
    13.0 12 
    27.8 25 
    15.4 25 
   100 6 

E1
E1
E1
E1
E1
  140.72
   72.99
   48.38
   12.37
    6.92
    0.0
1-
(3)+
2+
2+
(3)+
1+
  177.18 8  (3)-      20.4S
   49.8 2 
  104.4 2 
  128.9 3 
  164.8 1 
 
     8 2 
    26 6 
    72 20 
   100 20 




E1
  156.82
  127.31
   72.99
   48.38
   12.37
2-
(4+)
(3)+
2+
2+
  214.43 9  (4)-      37.3 1 
  141.4 1 
  158.5 2 
  194.5 3 
  207.6 2 
     5.7 10 
   100 19 
    15 4 
     6.6 19 
    34 9 



E1
E1
  177.18
   72.99
   55.83
   19.89
    6.92
(3)-
(3)+
(5+)
(4)+
(3)+
  290.8 3  (5-)     163.3 5 
  271.5 4 
   ≈50
   100 30 


  127.31
   19.89
(4+)
(4)+
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 3 - Possible Kπ=2+ band
    6.92 6  (3)+        
   12.37 5  2+      12.4S
 

    0.0
1+
   19.89 10  (4)+      13.0S
 

    6.92
(3)+
   55.83 13  (5+)      35.9 1 
   100

   19.89
(4)+
E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 4 - Possible Kπ=0- band
  340.25 12  (0)-        
  376.49 20  (2-)     103.1 4 
  328.0 3 
  364.1 3 
   ≈19
    33 14 
   100 14 



  273.64
   48.38
   12.37
1+
2+
2+

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Additional Gamma Data:













E(level)
(keV)		Jπ(level)T1/2(level)E(γ)
(keV)		MultipolarityConversion
Coefficient		Additional Data
   48.38 2+      48.40 5 M123.45α=23.45 34, α(L)=17.80 25, α(M)=4.24 6, α(N)=1.113 16, α(O)=0.249 4, α(P)=0.0399 6, α(Q)=0.002235 32
   72.99 (3)+      60.67 5 M112.08α=12.08 17, α(L)=9.17 13, α(M)=2.187 31, α(N)=0.574 8, α(O)=0.1282 18, α(P)=0.02057 29, α(Q)=0.001151 16
(3)+      72.9 1 (E2)39.1α=39.1 6, α(L)=28.8 4, α(M)=7.79 12, α(N)=2.041 32, α(O)=0.422 7, α(P)=0.0541 8, α(Q)=9.97×10-5 15
  127.31 (4+)      54.3 1 (M1)16.72α=16.72 25, α(L)=12.70 19, α(M)=3.03 5, α(N)=0.794 12, α(O)=0.1775 27, α(P)=0.0285 4, α(Q)=0.001594 24
  140.72 1-     128.4 3 E10.258α=0.258 4, α(K)=0.2027 31, α(L)=0.0420 6, α(M)=0.01007 15, α(N)=0.00260 4, α(O)=0.000559 9, α(P)=8.13×10-5 12, α(Q)=3.16E-6 5
1-     140.7 1 E10.2065α=0.2065 29, α(K)=0.1630 23, α(L)=0.0331 5, α(M)=0.00792 11, α(N)=0.002050 29, α(O)=0.000441 6, α(P)=6.46×10-5 9, α(Q)=2.57E-6 4
  156.82 2-      83.9 2 E10.1707α=0.1707 26, α(L)=0.1295 20, α(M)=0.0312 5, α(N)=0.00804 12, α(O)=0.001703 26, α(P)=0.000239 4, α(Q)=8.23×10-6 12
2-     108.43 5 E10.387α=0.387 5, α(K)=0.301 4, α(L)=0.0656 9, α(M)=0.01574 22, α(N)=0.00407 6, α(O)=0.000869 12, α(P)=0.0001247 18, α(Q)=4.63×10-6 7
2-     144.44 5 E10.1938α=0.1938 27, α(K)=0.1531 21, α(L)=0.0309 4, α(M)=0.00739 10, α(N)=0.001915 27, α(O)=0.000413 6, α(P)=6.05×10-5 8, α(Q)=2.422E-6 34
2-     149.90 5 E10.1770α=0.1770 25, α(K)=0.1401 20, α(L)=0.0281 4, α(M)=0.00671 9, α(N)=0.001739 24, α(O)=0.000375 5, α(P)=5.51×10-5 8, α(Q)=2.228E-6 31
2-     156.82 5 E10.1586α=0.1586 22, α(K)=0.1257 18, α(L)=0.02497 35, α(M)=0.00597 8, α(N)=0.001547 22, α(O)=0.000334 5, α(P)=4.93×10-5 7, α(Q)=2.012E-6 28
  177.18 (3)-     164.8 1 E10.1406α=0.1406 20, α(K)=0.1117 16, α(L)=0.02197 31, α(M)=0.00525 7, α(N)=0.001361 19, α(O)=0.000294 4, α(P)=4.35×10-5 6, α(Q)=1.799E-6 25
  214.43 (4)-     194.5 3 E10.0942α=0.0942 14, α(K)=0.0753 11, α(L)=0.01441 21, α(M)=0.00344 5, α(N)=0.000892 13, α(O)=0.0001936 28, α(P)=2.89×10-5 4, α(Q)=1.240E-6 18
(4)-     207.6 2 E10.0806α=0.0806 11, α(K)=0.0645 9, α(L)=0.01223 17, α(M)=0.00291 4, α(N)=0.000757 11, α(O)=0.0001645 23, α(P)=2.466×10-5 35, α(Q)=1.072E-6 15
  273.64 1+     225.3 2 M11.438α=1.438 20, α(K)=1.160 16, α(L)=0.2113 30, α(M)=0.0503 7, α(N)=0.01319 19, α(O)=0.00295 4, α(P)=0.000473 7, α(Q)=2.64×10-5 4
1+     261.3 2 M10.953α=0.953 13, α(K)=0.769 11, α(L)=0.1397 20, α(M)=0.0332 5, α(N)=0.00872 12, α(O)=0.001948 28, α(P)=0.000313 4, α(Q)=1.744×10-5 25
1+     273.7 4 M10.838α=0.838 12, α(K)=0.676 10, α(L)=0.1228 18, α(M)=0.0292 4, α(N)=0.00766 11, α(O)=0.001713 25, α(P)=0.000275 4, α(Q)=1.533×10-5 22
  299.91 (1)+     251.6 3 M11.058α=1.058 15, α(K)=0.853 12, α(L)=0.1552 22, α(M)=0.0369 5, α(N)=0.00969 14, α(O)=0.002165 31, α(P)=0.000347 5, α(Q)=1.938×10-5 28
(1)+     300.0 3 (M1)0.651α=0.651 9, α(K)=0.525 7, α(L)=0.0952 14, α(M)=0.02266 32, α(N)=0.00594 8, α(O)=0.001328 19, α(P)=0.0002131 30, α(Q)=1.189×10-5 17
  340.25 (0)-      40.4 3 (E1)1.206α=1.206 30, α(L)=0.912 22, α(M)=0.224 6, α(N)=0.0571 14, α(O)=0.01167 28, α(P)=0.001487 34, α(Q)=3.99×10-5 8
(0)-      66.6 1 E10.316α=0.316 5, α(L)=0.2399 35, α(M)=0.0581 8, α(N)=0.01492 22, α(O)=0.00313 5, α(P)=0.000428 6, α(Q)=1.371×10-5 20
(0)-     199.5 2 M12.021α=2.021 29, α(K)=1.629 23, α(L)=0.297 4, α(M)=0.0708 10, α(N)=0.01857 27, α(O)=0.00415 6, α(P)=0.000666 10, α(Q)=3.72×10-5 5
  355.13 (0-,2-)      55.3 2 (E1)0.521α=0.521 9, α(L)=0.394 7, α(M)=0.0959 16, α(N)=0.0246 4, α(O)=0.00511 9, α(P)=0.000683 11, α(Q)=2.053×10-5 33
(0-,2-)      81.5 3 (E1)0.1845α=0.1845 32, α(L)=0.1399 24, α(M)=0.0337 6, α(N)=0.00869 15, α(O)=0.001839 31, α(P)=0.000257 4, α(Q)=8.78×10-6 14

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
    0.01+ 27.4 s 3 
% β- = 0.35 5
% α = 99.65 5
μ=-0.66 1 (2014Ly01,2019StZV), Q=+0.487 8 (1987Du13,2021StZZ)
Isotope shift: Δ<r2>=-0.134 fm2 5 relative to 221Fr (2014Ly01). Other: Δ<r2>=+0.86725 fm 2 45 relative to 212Fr (1987Co19, corrected value of 1985Co24).
E(level): Kπ=1+ g.s. rotational band.
    6.92(3)+   E(level): Possible Kπ=2+ band.
   12.372+   E(level): Possible Kπ=2+ band.
   19.89(4)+   E(level): Possible Kπ=2+ band.
   48.382+   E(level): Kπ=1+ g.s. rotational band.
   55.83(5+)   E(level): Possible Kπ=2+ band.
   72.99(3)+   E(level): Kπ=1+ g.s. rotational band.
  127.31(4+)   E(level): Kπ=1+ g.s. rotational band.
  140.721-   E(level): Kπ=1- band.
  156.822-   E(level): Kπ=1- band.
  177.18(3)-   E(level): Kπ=1- band.
  200.21(5+)   E(level): Kπ=1+ g.s. rotational band.
  214.43(4)-   E(level): Kπ=1- band.
  246.8   E(level): From Eα.
  257.0   E(level): From Eα.
  290.8(5-)   E(level): Kπ=1- band.
  306.9   E(level): From Eα.
  340.25(0)-   E(level): Possible Kπ=0- band.
  376.49(2-)   E(level): Possible Kπ=0- band.
  380.1   E(level): From Eα.
  414.6   E(level): From Eα.
  442.2   E(level): From Eα.
  479.6   E(level): From Eα.
  579.9   E(level): From Eα.

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