Four-fragment exit channel in the interaction of 1050 MeV 84Kr with U studied with mica detectors.

Abstract

The interaction of 1050 MeV, /sup 84/Kr ions with natural uranium has been studied with the help of mica track detectors in the 2..pi.. configuration. Three ''direct'' and seven ''indirect'' events have been observed with four heavy fragments in the exit channel. These events represent a cross section of (16 +- 6) mb for this channel. The correlated tracks of two of the direct events have been used for kinematical analysis. The results indicate a two-step reaction mechanism. In the first step a ''quasifission'' process takes place which is followed by the sequential fission of at least one of the first step masses.