Analysis of the composition of a mixture of²⁴⁹Bk+²⁴⁹Cf on the basis of x rays

Conclusion

The results of the study enable us to conclude the following: the β decay of²⁴⁹Bk is accompanied by an L series of x rays from the daughter product Cf. The yield of this radiation is low: ω(L_α+L_β+ L_γ) ≈ 10⁻⁴ (β disintegration)⁻¹, but because of the high specific β activity of²⁴⁹Bk, 1 μg of this isotope emits ∼3.7·10⁵ x-ray quanta per minute. This enables us to detect a fairly small amount of Bk (∼0.01 μg) on the basis of x rays in a period of 5–10 min. The rapid accumulation of the daughter product²⁴⁹Cf does not interfere with the determination of the²⁴⁹Bk on the basis of x rays. Even when the mixture contains equal numbers of Bk and Cf nuclei, the ratio of the L_α lines corresponding to them is 0.46. Therefore the composition of a mixture of²⁴⁹Bk+²⁴⁹Cf can be determined on the basis of x rays over broad ranges of variation of the relative concentrations of Bk+Cf, roughly from 0.03 to 80. It is important to note that for relative measurements it is not necessary to prepare special specimens, since x rays with energies of 15–20 keV are not strongly absorbed in the solution and in the walls of the chemical vessel.