Neutron and fragment yields in proton-induced fission of 238U at intermediate energies

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 463; no. 3; pp. 653 - 662
• Main Authors: Rubchenya, V.A., Trzaska, W.H., Vakhtin, D.N., Äystö, J., Dendooven, P., Hankonen, S., Jokinen, A., Radivojevich, Z., Wang, J.C., Alkhazov, I.D., Evsenin, A.V., Khlebnikov, S.V., Kuznetsov, A.V., Lyapin, V.G., Osetrov, O.I., Tiourin, G.P., Aleksandrov, A.A., Penionzhkevich, Yu.E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2001
• Subjects: Fission fragment yields; Fission neutron multiplicities; Proton-induced fission; Statistical theory of fission; Time-of-flight technique; Time-of-flight technique; 29-40.Cs; 25-85.Ge; 29-40.Mc; Proton-induced fission; Fission fragment yields; 24-75.+i; 29-30.Hs; Fission neutron multiplicities; Statistical theory of fission
• DOI: 10.1016/S0168-9002(01)00176-0
• EISSN: 1872-9576
• ISSN: 0168-9002

The primary fission fragment mass and kinetic energy distributions, and neutron multiplicities as function of fragment mass have been measured in the proton-induced fission of
238U at energies
E
p=20,
35,
50 and 60
MeV using time-of-flight technique. Pre-scission and post-scission neutron multiplicities have been extracted from double differential distributions. The fragment mass dependence of the post-scission neutron multiplicities reveals the gross nuclear shell structure effect even at the higher proton energies we measured. The yields of neutron-rich fission products in the fission of
238U by 25
MeV protons were measured using an ion guide-based isotope separator technique. The results indicate enhancement for superasymmetric mass division at intermediate excitation energy of the fissioning nucleus. The experimental results have been analysed in the framework of a time-dependent statistical model with inclusion of nuclear friction effects in the fission process.