TWO-, THREE- AND FOUR-PARTICLE EXIT CHANNELS IN THE REACTION OF 14 MeV/amu BEAM OF 238U WITH GOLD TARGETS
Department of Physics
(*Department of Chemistry and Physics Radiation Centre)
University of Birmingham, Birmingham B15 2TT, UK.
Mica and CR-39 track detectors were used in 2π-geometry to allow coincidence measurements to be made of multiple fragments emerging in the reaction of 14 MeV/amu 238U projectiles on 197Au target nuclei. Targets were produced from sheets of muscovite mica as well as CR-39, both of which were coated with gold by vacuum deposition. These targets were irradiated with a beam of 238U ions, incident normally to the surface. After etching, the heavy fragments in the two-, three-, and four-particle exit channels were identified in respect of their masses and energies. Empirical velocity-range relationships in mica, which are explicitly dependent on mass, were found by fitting the Chebyshev series to the experimental data of the elastic scattering events. A correlation plot of the total kinetic energy loss (TKEL) for the two-pronged events due to elastic scattering have also been constructed. Cross sections for ternary and quarternary fission were determined and in addition, angular scattering measurements from elastic reactions were used to determine the total reaction cross section.
KEYWORDS: Heavy ion, nuclear track detector, 238U, gold, Chebyshev, cross section