The use of the U(n,f) reaction dosimetry in the determination of the lambda(f) value through fission-track techniques

A new set of determinations of the decay constant for spontaneous fission of (238)U, lambda(f), using mica-uranium sandwich and thin films of natural uranium is presented. A value of lambda(f) (8.37+/-0.17) x 10(-17) a(-1) has been determined. The use of uranium-based neutron dosimetry for the measurement of lambda(f) through fission-track techniques is discussed. Particularly, the lambda(f) measurement by Roberts et al. (Phys. Rev. 174 (1968) 4847), is analyzed, showing that the value obtained by these authors (7.03 x 10(-17) a(-1)) underestimated lambda(f). It is concluded that the dosimetry based on U(n,f) reaction does not support lambda(f) value around 7 x 10(-17)a(-1) determined by various authors using mica-uranium sandwich. (C) 2002 Elsevier Science B.V. All rights reserved.496121522