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)
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 "  
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);
    15 a-decays and 2 other levels  (and 49 associated gs) with yields < 0.1% omitted - full details here
  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