Mass and charge distributions in the very asymmetric thermal neutron induced fission of the odd-Z nucleus Am-242m

Tsekhanovich I., Denschlag H. O., Davi M., BÜYÜKMUMCU Z., Wostheinrich M., Gonnenwein F., ...More

NUCLEAR PHYSICS A, vol.658, no.3, pp.217-239, 1999 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 658 Issue: 3
  • Publication Date: 1999
  • Doi Number: 10.1016/s0375-9474(99)00338-3
  • Journal Name: NUCLEAR PHYSICS A
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.217-239
  • Erciyes University Affiliated: No

Abstract

Yields of light fission products (A = 68, 70-84, 87, 88, 94, 96, 98, 102 and 106-108), their kinetic energies and nuclear charge distributions (A = 71-84, 87 and 88) in the thermal neutron induced fission of the odd-Z nucleus Am-242m(Z = 95) were measured using the mass-separator Lohengrin at the Institute Laue-Langevin in Grenoble (France). The mass yield curve shows a fine structure at A = 70, probably due to shell and/or odd-even effects affecting also the nuclear charge distribution. The analysis of isotopic chain yields gives evidence for a very low excitation energy of the lightest fission fragments observed. A preferential formation of fragments with even Z is found for this odd-Z compound nucleus, Calculated values for the local odd-even effect are comparable with those for the neighbouring even-Z fissile nuclides and increase from 13% to 30% with increasing asymmetry of the mass split (A(L) = 84 to 68 and Z(L) = 35 to 28). The neutron odd-even effect shows a similar but less pronounced behaviour. (C) 1999 Elsevier Science B.V. All rights reserved.