Электронный каталог

Статья

Sailaubekov, B.
First Investigation of Prompt Neutrons from Spontaneously Fissioning Isomers Produced in Multinucleon Transfer Reactions / B.Sailaubekov, A.I.Svirikhin, H.M.Devaraja, A.V.Isaev, R.S.Mukhin, M.A.Bychkov, M.L.Chelnokov, V.I.Chepigin, V.D.Danilkin, I.N.Izosimov, Sh.A.Kalandarov, D.E.Katrasev, A.A.Kuznetsova, O.N.Malyshev, A.G.Popeko, Yu.A.Popov, E.A.Sokol, E.Teymurov, M.S.Tezekbayeva, I.I.Ulanova. – Text : electronic // Physics Letters B. – 2026. – Vol. 872. – P. 140071. – URL: https://doi.org/10.1016/j.physletb.2025.140071. – Bibliogr.: 30.

This work presents the first experimental results on prompt neutron multiplicities from short-lived spontaneously fissioning isomers produced in the multinucleon transfer (MNT) reaction of &sup(26)Mg + &sup(238)U. The observed prompt neutron multiplicity distribution yields an average neutron number of *n^- = 2.65 *{ 0.20 and a variance of *g&sup(2)&sub(*n) = 1.4. The half-life of the spontaneously fissioning products was determined to be 𝑇&ub(1∕2) = 5.3&sup(+0.5)&sub(−0.4) *ms. The shape of the multiplicity distribution of prompt fission neutrons was restored using the Tikhonov regularization technique and is characterized by a symmetrical distribution. Among the known spontaneous fission isomers, &sup(239𝑚)Pu and &sup(243𝑚)Am exhibit half-lives and prompt neutron multiplicities that agree with the measured values within uncertainties. GEF model estimates yield *n^- = 2.54 *{ 0.20 for &sup(239𝑚)Pu and *n^-= 2.91 *{ 0.20 for &sup(243𝑚)Am, with the former showing slightly better agreement. Whether the activity arises from a single isomer or a mixture of both remains unresolved, as the current data do not allow for a clear separation of their contributions. Further high-statistics measurements, including fission fragment total kinetic energy and gamma-ray spectroscopy, are required for unambiguous identification of the fissioning nucleus.



Спец.(статьи,препринты) = С 341.3г - Спонтанное деление
Спец.(статьи,препринты) = С 341.3д - Вторичные и запаздывающие нейтроны
ОИЯИ = ОИЯИ (JINR)2026