def thePu239_lamda
      array = Array.new(23)

      array[0] = 1.002E+01
      array[1] = 6.433E-01
      array[2] = 2.186E-01
      array[3] = 1.004E-01
      array[4] = 3.728E-02
      array[5] = 1.435E-02
      array[6] = 4.549E-03
      array[7] = 1.328E-03
      array[8] = 5.356E-04
      array[9] = 1.730E-04
      array[10] = 4.881E-05
      array[11] = 2.006E-05
      array[12] = 8.319E-06
      array[13] = 2.358E-06
      array[14] = 6.450E-07
      array[15] = 1.278E-07
      array[16] = 2.466E-08
      array[17] = 9.378E-09
      array[18] = 7.450E-10
      array[19] = 2.426E-10
      array[20] = 2.210E-13
      array[21] = 2.640E-14
      array[22] = 1.380E-14

      array
    end
def thePu239_lamda
      array = Array.new(23)

      array[0] = 1.002E+01
      array[1] = 6.433E-01
      array[2] = 2.186E-01
      array[3] = 1.004E-01
      array[4] = 3.728E-02
      array[5] = 1.435E-02
      array[6] = 4.549E-03
      array[7] = 1.328E-03
      array[8] = 5.356E-04
      array[9] = 1.730E-04
      array[10] = 4.881E-05
      array[11] = 2.006E-05
      array[12] = 8.319E-06
      array[13] = 2.358E-06
      array[14] = 6.450E-07
      array[15] = 1.278E-07
      array[16] = 2.466E-08
      array[17] = 9.378E-09
      array[18] = 7.450E-10
      array[19] = 2.426E-10
      array[20] = 2.210E-13
      array[21] = 2.640E-14
      array[22] = 1.380E-14

      array
    end
thePu239_lamda is lamda in ANS-5.1-1979 Table 8.