Recoil studies of fission products formed in the fission of 238U by protons of energies 25–85 MeV

Abstract

definite correlati on was observed between the anisotrop y and the depositio n energy.

Nuclear charge distribution in the region of symmetric fission of 238U by protons of energy 20–85 MeV

“…The most probable charge, Z,, shifts to less neutron-rich nuclides with increasing bombard- uranium showed that E*, leading to products in the symmetric mass region, is not very different than at an energy of 450 MeV. However, in the present energy range, the work of Ramamoorthy et al (18) shows a significant variation in E* of primary fragments in the symmetric mass region as the bombardment energy is increased.…”

“…The degradation in proton bombardment energy introduced by the target thickness was computed at each energy from the data of Williamson et al (17) and was found to lie within the k 2 MeV spread in the energy of the internal circulating beam of the McGill synchrocyclotron. The target assembly consisted of the following, (i) uranium foil, cleaned with dilute HN03 to remove the oxide coating, subsequently washed with water, acetone, and dried, (ii) high-purity Al catcher foils (front and back) approximately 10 mg cm-2 superficial density, sufficient to stop the recoil of the fission fragments (18,19) and (iii) a Cu monitor coil (99.99% pure) of superficial density 44 mg ~m -~ upstream of the target. Estimates (20,21) of the range of the copper recoil atoms indicate a maximum loss due to recoil of less than 0.003% and thus no catcher foils were used with the monitor foil.…”