COMPARISON OF METHODS FOR ANALYZING THE MASS-ENERGY DISTRIBUTIONS OF FISSION FRAGMENTS USING THE EXAMPLE OF THE DISTRIBUTIONS OF FRAGMENTS OF THE COMPOUND NUCLEUS ²⁴¹Am OBTAINED IN THE REACTION ²⁴⁰Pu(p,f AT AN INCIDENT PROTON ENERGY OF 10 MeV

The mass-energy distributions of fission fragments are formed by a large number of macroscopic and microscopic quantum effects associated with both charged liquid droplet effects and the formation of various nuclear shells in nascent fragments. Additionally, the final distribution is influenced by the excitation energy of the compound nucleus and the introduced angular momentum. All of this poses a challenge in analyzing experimental data for the presence/absence of various shell effects. This is particularly true for deformed nuclear shells, which, compared to spherical shells, have a significantly lower energy advantage for formation and, consequently, a smaller mass contribution. Therefore, the choice of analysis technique significantly influences the obtained result. To demonstrate this, we analyze the mass-energy distributions of fission fragments of the compound nucleus ²⁴¹Am produced in the ²⁴⁰Pu(p,f) reaction at an incident proton energy of 10 MeV using two methods. The first method is an earlier development based on the Broza model and takes into account the SL, S1, S2, and S3 fission modes, using a large number of fit parameters. The second method is a modification of the first, developed specifically to identify the influence of deformed nuclear shells with small contributions. Its advantages include a significant reduction in the number of fit parameters, which increases its sensitivity. The second method makes it possible to identify the yields of individual Z50 and N82 shells and separate them from the deformed Z52 and N84 nuclear shells, despite their similar mass yields.

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