[en] The object of the experiment is to measure the frequency with which nucleons within a parent nucleus coalesce into clusters. The experiment is being carried out at the Bevatron with heavy ion beams of 2.1 GeV kinetic energy per nucleon. The extracted heavy ion beam is directed onto a target in which many interactions occur. The interactions of interest are those in which the incident nucleus fragments into two daughter nuclei. These events are selected from the background by scintillation counters and associated fast electronics