231 Pa decay; t1/2 = 32.8 ky (t = 47.3 ky).

  1. 231Pa [a (+ g)] 227Ac
g + c.e.(a) a
E(b) I(c) (c) Ic.e. E(b) I(c)
600.0 2.2 10-7 1.9 10-9 4410 7.9 10-7
583.0 1.3 10-7 1.2 10-9 "  
572.0 2.2 10-7 2.1 10-9 "  
547.0 2.2 10-7 2.4 10-9 "  
536.0 2.2 10-7 2.4 10-9 4507 8.8 10-7
516.0 5.7 10-7 6.9 10-9 "  
510.0 1.3 10-7 1.6 10-9 4530 4.4 10-7
491.0 1.3 10-7 1.7 10-9 "  
501.0 2.6 10-7 3.2 10-9 4565 3.5 10-6
427.0 2.6 10-5 4.5 10-7 "  
385.0 1.8 10-6 4.0 10-8 4598 6.6 10-6
359.0 4.0 10-6 1.0 10-7 "  
438.0 1.8 10-6 3.1 10-8 4629 2.5 10-5
411.0 8.4 10-7 1.5 10-8 "  
392.0 3.0 10-6 6.0 10-8 "  
364.0 3.3 10-6 8.5 10-8 "  
51.0 6.2 10-7 1.6 10-5 "  
435.0 1.5 10-6 2.5 10-8 4631 2.2 10-5
408.0 1.5 10-5 5.3 10-6 "  
398.0 4.1 10-6 7.8 10-8 4642 4.4 10-5
396.0 1.1 10-6 2.3 10-8 "  
379.0 2.0 10-5 6.8 10-6 "  
352.0 1.8 10-7 4.6 10-9 "  
387.0 2.2 10-7 1.8 10-8 4680 6.6 10-4
357.0 6.8 10-5 3.1 10-5 "  
341.0 7.7 10-5 8.6 10-6 "  
313.0 5.0 10-5 1.6 10-5 "  
303.0 2.8 10-4 1.0 10-5 "  
277.0 2.7 10-5 1.4 10-5 "  
260.0 8.0 10-5 4.5 10-5 "  
57.2 6.6 10-6 1.0 10-3 "  
355.0 3.6 10-5 1.7 10-5 4712 4.4 10-4
327.0 1.3 10-5 4.0 10-7 "  
24.7 1.8 10-6 3.9 10-4 "  
330.0 5.8 10-4 2.2 10-4 4736 0.0037
303.0 7.0 10-4 2.5 10-5 "  
300.0 0.0011 4.9 10-4 "  
284.0 7.0 10-4 2.9 10-5 "  
256.0 4.4 10-5 1.2 10-5 "  
245.0 3.1 10-6 1.7 10-5 "  
258.0 1.0 10-6 2.7 10-7 4760 2.0 10-6
230.0 7.0 10-7 4.7 10-8 "  
273.0 2.5 10-5 1.9 10-5 4791 8.6 10-5
246.0 3.1 10-6 1.8 10-7 "  
243.0 2.1 10-5 1.6 10-5 "  
199.0 2.6 10-6 2.4 10-7 "  
144.0 1.8 10-6 3.9 10-6 4792 2.4 10-5
72.5 1.8 10-6 1.6 10-5 "  
101.0 1.4 10-5 1.4 10-4 4851 6.2 10-4
23.6 1.5 10-6 4.4 10-4 "  
125.0 2.2 10-6 9.1 10-6 4864 (fed)(d)
71.9 8.8 10-7 8.4 10-6 "  
103.0 5.7 10-6 5.4 10-5 4875 (fed)(d)
77.4 3.0 10-5 2.3 10-4 "  
60.5 3.1 10-6 1.4 10-6 "  
? ? ? 4899 8.8 10-7
96.9 3.9 10-5 4.7 10-4 4933 0.0013
52.7 3.7 10-5 8.8 10-4 "  
63.7 2.2 10-5 0.0020 4950 0.010
35.8 7.0 10-6 1.2 10-5 "  
25.5 4.0 10-5 0.0079 "  
57.2 1.1 10-5 0.0017 4974 1.8 10-4
54.6 3.6 10-5 2.1 10-5 "  
38.2 6.6 10-5 0.0049 "  
74.2 1.1 10-5 4.8 10-4 4984 6.2 10-4
44.2 2.6 10-5 0.0010 "  
46.4 9.2 10-5 9.1 10-5 5011 0.011
18.9 1.5 10-4 0.018 "  
16.5 2.2 10-4 7.8 10-4 "  
30.0 4.0 10-5 0.011 5028 0.0088
27.4 0.0041 0.015 5030 0.0011
      5057 0.0048

Notes:                                                                     

  1. c.e.: conversion electrons
  2. Energies in keV
  3. Intensities per `parent' decay of natural U (i.e. 0.956 238U, 0.044 235U)
  4. Data from compilations and amendments in Nuclear Data Sheets to Vol. 64 (1991)
    Levels marked `(fed)' receive no direct a-decay, but are fed by gs from higher levels
  5. g and conversion electron intensities are totals from given level; part may be associated with different (lower energy) primaries
  6. 231Pa entry in KAERI nuclide chart