Abstract
Shell effects are most pronounced in mass and energy distributions of fission fragments at the lowest excitation energy of compound nucleus. To study shell effects the mass and energy distributions of fission fragments of 241Am* compound nucleus in 240Pu(p,f) reaction were measured at incident proton energy of 7 MeV. This energy is substantially lower than coulomb barrier for this reaction leading to very small reaction cross-section and low speed of data acquisition. Due to that the results we provide are only preliminary and final results will be provided later after acquisition of additional statistics. The measurement was carried out by 2E method on U-150M accelerator of Institute of Nuclear Physics, Almaty city, Kazakhstan. The acquired preliminary mass and energy distributions were decomposed into yields of separate fission shells assuming that the shape of mass yield of each fission mode is gauss distribution.