The Average Number of Neutrons Emitted in the Spontaneous Fission of Some Even-Even Heavy Nuclides

The values of the average number of prompt neutrons emitted in the spontaneous fission of some recently available even-even heavy nuclides have been determined by separately counting neutrons and spontaneous fissions and comparing these counts with similar counts from ²⁵²Cf standards. The results are as follows: ²⁴⁴Pu , ²⁴⁸Cm , ²⁵⁰Cm , ²⁵⁰Cf , ²⁵⁴Cf , all on the basis of for ²⁵²Cf. A comparison of these results with existing data for other heavy nuclides indicates that is both Z and A dependent in a manner similar to that calculated by Bondarenko et al.