COLLISION PROCESSES OF ION, POSITRON, ELECTRON AND PHOTON BEAMS WITH MATTER - PROCEEDINGS OF ELAF 91

The proceedings contain lectures and contributed papers presented at the Latin American School of Physics in Caxambu, Brazil. Topics are related to a review of collision processes, excitation and ionization of molecules, ion formation by electron impact, mass and energy spectroscopy in collision reactions, desorption induced by ion and electron beams, and principles and applications of synchrotron radiation. The major theme of the school was "Current methods in collision processes.".