OBSERVATION OF PLANAR OSCILLATIONS OF MEV PROTONS IN SILICON USING ION CHANNELING PATTERNS

This paper describes the observation of {110} planar oscillations of 3 MeV protons transmitted through a 0.5 mu m thick [001] silicon crysta l using ion channeling patterns produced on a fluorescent viewing scre en. Gradual variations in the crystal thickness allowed the exit angul ar distribution of the protons to be sampled al different depths into the crystal, revealing effects due to the coherent planar oscillations . This work necessitated the use of a focused MeV proton beam from a n uclear microprobe to generate channeling patterns from selected, micro n-size regions and the necessary ion optics are developed here. The re corded channeling patterns are interpreted with the help of Monte Carl o computer simulations.