Fission fragment-light particle coincidences and linear momentum transfer

Linear momentum transfer in ⁴⁰Ar + ¹⁹⁷Au at 19.6 {MeV}/{u} and ⁴⁰Ar + ²³⁸U at 19.6 and 35 {MeV}/{u} has been investigated by measuring the correlation angle between two fission fragments. Fast light charged particles were measured in coincidence with fission events. Results show that the main part of the missing linear momentum is likely removed by a piece of the projectile after it has broken up. A change in the reaction mechanism seems to occur around 35 {MeV}/{u}. An interpretation, in terms of the highest possible energy content in a nuclear system is suggested.