Heavy‐ion projectiles produce a new kind of fission

Nuclear scientists studying the reactions induced by heavy ions have encountered an unexpected process that has been variously dubbed “quasifission,” “deep inelastic transfer,” “relaxed‐peak process,” “incomplete fusion” and “strongly damped collisions.” In this process the reaction products have the kinetic energies typical of fission products, but their masses differ from what one would expect in fission: In the latter process, each of the reaction products has a mass roughly equal to one‐half of the total mass of the compound nucleus (target plus projectile). In quasifission the two product nuclei have masses close to those of the target and projectile, individually.