A search for fine structure in the time-of-flight spectrum of the fission neutrons of ²⁵²Cf

A standard time-of-flight arrangements, in which start pulses were supplied by fission fragments and stop pulses by neutrons, has been employed in an attempt to check recent claims of the existence of fine structure in the time-of-flight spectrum of the fission neutrons of ²⁵²Cf. This structure, in the form of spikes with tails towards longer times, has been attributed to the emission of neutrons of short delay (with half-lives of a few to a hundred or so nanoseconds) in the fission process. The authors have been unable to find any convincing evidence for the existence of such structure.