Mass distributions for the fission of 250Cf

The yields of 40 fission products for the ²⁴⁹Cf (n_th, f) reaction have been determined. The yields are compared with those determined previously and a composite mass distribution is deduced with the average mass for the light group $\text{A}{}_{\mathrm{L}}$ equal to 105.9±0.2 and for the heavy group $\text{A}{}_{\mathrm{H}}$ equal to 140.0±0.2. The peak-to-valley ratio $\text{P}\text{V}$ is ∼ 26. Four new yields for the spontaneous fission of ²⁵⁰Cf have also been determined. The characteristics for this mass distribution are $\text{A}{}_{\mathrm{L}}\text{= 105.4±0.2,}\text{A}{}_{\mathrm{H}}\text{= 141.6±0.2}$, and $\text{P}\text{V}\text{⪖ 310}$.