ADOPTED LEVELS, GAMMAS for 224Ac

Authors: Balraj Singh, Sukhjeet Singh |  Citation: ENSDF |  Cutoff date: 08-Mar-2022 

Authors: Sukhjeet Singh, Balraj Singh |  Citation: Nucl. Data Sheets 130, 127 (2015) |  Cutoff date: 15-Oct-2015 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=239 keV 10S(n)= 5662 keV 8S(p)= 4288 keV 4Q(α)= 6326.9 keV 7
Reference: 2021WA16

References:
  A  228Pa α decay (19.5 H) 

General Comments:

224Ac identified and produced by 1948Gh01 in Th(d,X) at 80 MeV, with an estimated half-life of ≈2.5 h. Later studies of 224Ac decay: 1951Me10, 1958Hi78, 1968Le17, 1976MiZR, 1987Mi10, 1992Li31.

Theoretical calculations: 24 references extracted from the NSR database are listed in document records.

All data are from 228Pa α decay

In this evaluation, the level scheme is essentially that proposed by 1994Ah03 with some modifications suggested in 2004Sh25. The band structures are taken essentially from 2004Sh25, but considered tentative at this stage. As pointed out in 1994Ah03 and 2004Sh25, the level scheme of 224Ac is very complex and many additional levels are expected. Thus the level scheme presented here is considered as incomplete. Information about confirmed multipolarities, mixing ratios and other spectroscopic details is lacking. Further experiments on the decay of 228Pa, and involving nuclear reactions are needed to confirm and elucidate the structure of this nucleus.

2004Sh25 suggest five other bands, not listed here, for which only one or two levels each are known.

Q-value: S(2n)=12530 6, S(2p)=10722 8 (2021Wa16)










E(level)
(keV)
XREFJπ(level) T1/2(level)E(γ)
(keV)
I(γ)M(γ)Final Levels
    0A (0-) 2.78 h 16 
% ε = 90.9 +14-20
% α = 9.1 +20-14
     
   17.60 15 A (1-)        
   23.40 11 A (2-)        
   29.83 9 A (1+)      29.8 1 
   100
E1
    0
(0-)
   34.2 8 ?A        
   37.17 9 A (2-)      37.2 1 ?
   100
[E2]
    0
(0-)
   44.2 3 ?A        
   45.8 4 ?A (-)        
   47.4 4 ?A        
   49.08 13 A (3-)        
   52.20 11 A (2+)      22S
   28.8 1 
   34.6 1 
 
    42 7 
   100 11 

E1
E1
   29.83
   23.40
   17.60
(1+)
(2-)
(1-)
   64.47 14 A (3+)      41.1 1 
   100

   23.40
(2-)
   65.2 6 ?A        
   75.9 6 ?A        
   78.51 12 A (3-)      26.3 1 
   100 14 
E1
   52.20
(2+)
   80.49 10 A (3+)      28.3 1 
   43.3 1 
    ≈4.2
   100 13 

E1
   52.20
   37.17
(2+)
(2-)
   84.1 4 ?A        
   90.56 13 A (+)      67.2 1 
   100
(E1)
   23.40
(2-)
   92.6 4 ?A        
  100.44 23 ?A        
  103.31 13 A (4+)      54.2 1 
   100
(E1)
   49.08
(3-)
  105.1 6 ?A        
  109.33 17 A (4-)      60.3 2 
   100

   49.08
(3-)
  110.53 15 A (+)      61.5 1 
   100

   49.08
(3-)
  116.46 13 A (4-)      36.0 1 
   52.0 2 
   100 15 
    87 15 
(E1)

   80.49
   64.47
(3+)
(3+)
E(level)
(keV)
XREFJπ(level) T1/2(level)E(γ)
(keV)
I(γ)M(γ)Final Levels
  130.30 11 A (4+)      49.8 1 
   51.8 1 
   78.6 3 ?
   81.2 1 
    20 4 
   100 11 
     8 4 
    89 15 

(E1)


   80.49
   78.51
   52.20
   49.08
(3+)
(3-)
(2+)
(3-)
  133.4 4 ?A        
  142.5 3 A (5+)        
  146.6 4 A      62.5 1 ?
   100 17 

   84.1

  159.3 4 A      66.3 3 ?
   75.5 3 ?
   ≈50
  ≈100


   92.6
   84.1


  169 2 A        
  176.72 14 A (5+)      46.5 2 
   60.3 2 
   67.4 2 
   73.4 2 
   ≈30
  <125
   100 15 
    21 9 

(E1)


  130.30
  116.46
  109.33
  103.31
(4+)
(4-)
(4-)
(4+)
  183.40 13 A (5-)      53.1 1 
   74.1 3 
   80.1 1 
   100 15 
    38 10 
    85 15 
(E1)

(E1)
  130.30
  109.33
  103.31
(4+)
(4-)
(4+)
  212 2 A        
  219.7 4 A      77.2 2 
   86.3 2 ?
  ≈100
   ≈67


  142.5
  133.4
(5+)

  236.5 4 A (6-)      59.8 3 
   100

  176.72
(5+)
  252.68 17 A (6+)      69.3 2 
   76.0 2 
  110.3 4 
  122.5 5 
   100 17 
    43 12 
    86 17 
   ≈23
(E1)



  183.40
  176.72
  142.5
  130.30
(5-)
(5+)
(5+)
(4+)
  283.48 13 A (3-)     140.8 4 
  193.0 2 
  237.7 3 ?
  246.2 2 
  260.1 1 
    20 5 
    11 4 
    26 5 
    36 8 
   100 11 


(M1)


  142.5
   90.56
   45.8
   37.17
   23.40
(5+)
(+)
(-)
(2-)
(2-)
E(level)
(keV)
XREFJπ(level) T1/2(level)E(γ)
(keV)
I(γ)M(γ)Final Levels
  300 2 A        
  317.2 5 A     280.0 5 
  283.0 5 ?
  ≈100
  ≈100


   37.17
   34.2
(2-)

  333.04 12 A (3+)     202.7 1 
  222.7 2 
  232.6 2 ?
  242.6 2 
  252.6 2 
  267.8 5 ?
  280.8 4 
  283.4 4 
  285.8 5 ?
  288.9 5 ?
  295.5 4 
  303.2 2 
    88 13 
   ≈16
    59 9 
    47 8 
    63 13 
    33 11 
   ≈31
   ≈47
   ≈16
   ≈47
   ≈31
   100 18 
M1(+E2)


(M1)
(M1)







  130.30
  110.53
  100.44
   90.56
   80.49
   65.2
   52.20
   49.08
   47.4
   44.2
   37.17
   29.83
(4+)
(+)

(+)
(3+)

(2+)
(3-)


(2-)
(1+)
  353.89 11 A (3-)     237.5 2 
  244.7 5 
  248.8 5 ?
  269.1 4 ?
  278.0 5 ?
  290.0 5 
  309.6 3 ?
  316.8 1 
  330.4 1 
    18.9 23 
     9.6 23 
     7.7 27 
    13 3 
    ≈9
   ≈23
   ≈23
   100 14 
   <50
(M1)
(M1)





(M1)
(M1)
  116.46
  109.33
  105.1
   84.1
   75.9
   64.47
   44.2
   37.17
   23.40
(4-)
(4-)



(3+)

(2-)
(2-)
  360.25 11 A (3+)     230.0 1 
  268.7 5 ?
  279.5 4 
  308.0 1 
  312.8 4 ?
  330.4 1 
    45 8 
     9 2 
     9.3 23 
   100 10 
    ≈5.0
   <28
M1(+E2)


M1(+E2)


  130.30
   90.56
   80.49
   52.20
   47.4
   29.83
(4+)
(+)
(3+)
(2+)

(1+)
E(level)
(keV)
XREFJπ(level) T1/2(level)E(γ)
(keV)
I(γ)M(γ)Final Levels
  380.80 16 A (+)     250.5 2 
  300.3 3 
  328.6 2 
  351.0 4 
    59 12 
   ≈17
   100 14 
   ≈17
(M1)



  130.30
   80.49
   52.20
   29.83
(4+)
(3+)
(2+)
(1+)
  395.84 19 A (4-)     212.5 5 
  253.4 5 
  317.2 2 
  347.0 3 
   ≈42
   ≈67
  ≈580
   100 42 




  183.40
  142.5
   78.51
   49.08
(5-)
(5+)
(3-)
(3-)
  402.92 16 A (4+)     226.3 2 
  299.5 3 
  312.3 3 
  322.4 2 
   ≈17
   ≈33
   ≈17
   100 13 



M1(+E2)
  176.72
  103.31
   90.56
   80.49
(5+)
(4+)
(+)
(3+)
  448.08 20 A (5-)     195.5 2 
  317.8 3 
  344.3 4 
   100 30 
  ≈300
  ≈100



  252.68
  130.30
  103.31
(6+)
(4+)
(4+)
  452.1 4 A (5+)     335.6 3 
   100

  116.46
(4-)

Jπ(level): Assignments are mainly from 2004Sh25 based on interpretation of parity-doublets (reflection asymmetric) structures in 224Ac. Some of the assignments are supported by transition multipolarities from conversion electron data for high energy transitions and E1 assignments from I(K-x ray)/Iγ ratios. For the Kπ=0 and 1 bands, two scenarios are presented in their figures 4 and 5 of 2004Sh25. See detailed discussion by the authors. Assignments given here are arbitrarily taken from figure 4 in 2004Sh25. Kπ=3+ and 3- parity- doublet bands are also supported by 1994Ah03 with minor differences in level assignments at high energy.

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Band Transitions:

E(level)
(keV)
Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 1 - Band based on (0-).
    0 (0-) 2.78 h 16 
% ε = 90.9 +14-20
% α = 9.1 +20-14
     
   17.60 15  (1-)        
   37.17 9  (2-)        
   78.51 12  (3-)      26.3 1 
   100 14 
E1
   52.20
(2+)
  116.46 13  (4-)        
  183.40 13  (5-)      53.1 1 
   74.1 3 
   80.1 1 
   100 15 
    38 10 
    85 15 
(E1)

(E1)
  130.30
  109.33
  103.31
(4+)
(4-)
(4+)
  236.5 4  (6-)        
E(level)
(keV)
Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 2 - Band based on 1+.
   29.83 9  (1+)        
   52.20 11  (2+)        
   80.49 10  (3+)        
  130.30 11  (4+)      49.8 1 
   51.8 1 
   78.6 3 ?
   81.2 1 
    20 4 
   100 11 
     8 4 
    89 15 

(E1)


   80.49
   78.51
   52.20
   49.08
(3+)
(3-)
(2+)
(3-)
  176.72 14  (5+)        
  252.68 17  (6+)      69.3 2 
   76.0 2 
  110.3 4 
  122.5 5 
   100 17 
    43 12 
    86 17 
   ≈23
(E1)



  183.40
  176.72
  142.5
  130.30
(5-)
(5+)
(5+)
(4+)
E(level)
(keV)
Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 3 - Band based on (3-).
  353.89 11  (3-)        
  395.84 19  (4-)        
  448.08 20  (5-)        
E(level)
(keV)
Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 4 - Band based on (3+).
  360.25 11  (3+)        
  402.92 16  (4+)        
  452.1 4  (5+)        

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Additional Gamma Data:















E(level)
(keV)
Jπ(level)T1/2(level)E(γ)
(keV)
MultipolarityMixing
Ratio
Conversion
Coefficient
Additional Data
   29.83 (1+)      29.8 1 E1 2.83α=2.83 5
   37.17 (2-)      37.2 1 [E2] 1200α=1200 24
   52.20 (2+)      28.8 1 E1 3.10α=3.10 6
(2+)      34.6 1 E1 1.91α=1.91
   78.51 (3-)      26.3 1 E1 3.93α=3.93 7
   80.49 (3+)      43.3 1 E1 1.054α=1.054 17
   90.56 (+)      67.2 1 (E1) 0.327α=0.327
  103.31 (4+)      54.2 1 (E1) 0.580α=0.580
  116.46 (4-)      36.0 1 (E1) 1.72α=1.72 3
  130.30 (4+)      51.8 1 (E1) 0.654α=0.654
  176.72 (5+)      60.3 2 (E1) 0.436α=0.436 8
  183.40 (5-)      53.1 1 (E1) 0.612α=0.612
(5-)      80.1 1 (E1) 0.205α=0.205
  252.68 (6+)      69.3 2 (E1) 0.301α=0.301
  283.48 (3-)     237.7 3 (M1) 1.473α=1.473
  333.04 (3+)     202.7 1 M1(+E2)0.6 LT2.07α=2.07 23
(3+)     242.6 2 (M1) 1.392α=1.392
(3+)     252.6 2 (M1) 1.244α=1.244
  353.89 (3-)     237.5 2 (M1) 1.476α=1.476
(3-)     244.7 5 (M1) 1.359α=1.359
(3-)     316.8 1 (M1) 0.666α=0.666
(3-)     330.4 1 (M1) 0.593α=0.593
  360.25 (3+)     230.0 1 M1(+E2)0.7 LT1.41α=1.41 21
(3+)     308.0 1 M1(+E2)0.4 LT0.68α=0.68 4
  380.80 (+)     250.5 2 (M1) 1.273α=1.273
E(level)
(keV)
Jπ(level)T1/2(level)E(γ)
(keV)
MultipolarityMixing
Ratio
Conversion
Coefficient
Additional Data
  402.92 (4+)     322.4 2 M1(+E2)0.7 LT0.55α=0.55 9

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
    0(0-) 2.78 h 16 
% ε = 90.9 +14-20
% α = 9.1 +20-14
E(level): Band based on (0-).
   17.60(1-)   E(level): Band based on (0-).
   29.83(1+)   E(level): Band based on 1+.
   37.17(2-)   E(level): Band based on (0-).
   52.20(2+)   E(level): Band based on 1+.
   78.51(3-)   α 48.6γ is omitted here due to unlikely M2 multipolarity implied from assigned Jπ values.
E(level): Band based on (0-).
   80.49(3+)   E(level): Band based on 1+.
  116.46(4-)   E(level): Band based on (0-).
  130.30(4+)   E(level): Band based on 1+.
  176.72(5+)   E(level): Band based on 1+.
  183.40(5-)   E(level): Band based on (0-).
  236.5(6-)   E(level): Band based on (0-).
  252.68(6+)   E(level): Band based on 1+.
  353.89(3-)   E(level): Band based on (3-).
  360.25(3+)   E(level): Band based on (3+).
  395.84(4-)   E(level): Band based on (3-).
  402.92(4+)   E(level): Band based on (3+).
  448.08(5-)   E(level): Band based on (3-).
  452.1(5+)   E(level): Band based on (3+).

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Additional Gamma Comments:

E(level)E(gamma)Comments
   64.47   41.1M(γ): (M1) listed in 1993Sh07, but no argument given
  109.33   60.3E(γ): Multiply placed with undivided intensity
I(γ): Multiply placed with undivided intensity
  176.72   60.3E(γ): Multiply placed with undivided intensity
I(γ): Multiply placed with undivided intensity
  353.89  330.4E(γ): Multiply placed with undivided intensity
I(γ): Multiply placed with undivided intensity
  360.25  330.4E(γ): Multiply placed with undivided intensity
I(γ): Multiply placed with undivided intensity

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