A study of the relationship between spatial and angular coordinates of axially channeled MeV protons

Monte Carlo channeling simulations for 3 MeV protons which are transmitted close to the [011] axis of a silicon layer up to 200 nm thick are presented . The emergent angular intensity at different incident tilt angles and laye r thicknesses is related to the spatial distribution of the channeled proto ns across the [011] unit cell. The transition between a channeling regime w here the angular intensity distribution is dominated by 'rainbow' channelin g, and a regime which is characterised by a 'doughnut' distribution is stud ied for different tilt angles. (C) 1999 Elsevier Science B.V. All rights re served.