NUMERICAL MODELING OF MATERIALS PROCESSING APPLICATIONS OF A PULSED COLD-CATHODE ELECTRON-GUN

A numerical study of the application of a pulsed cold cathode electron gun to materials processing is performed. A simple semiempirical mode l of the discharge is used, together with backscattering and energy de position profiles obtained by a Monte carlo technique, in order to eva luate the energy source term inside the material. The numerical comput ation of the heat equation with the calculated source term is performe d in order to obtain useful information on melting and vaporization th resholds, melted radius and depth, and on the dependence of these vari ables on processing parameters such as operating pressure, initial vol tage of the discharge and cathode-sample distance. Numerical results f or stainless steel are presented, which demonstrate the need for sever al modifications of the experimental design in order to achieve a bett er efficiency. (C) 1998 American Institute of Physics. [S0021-8979(98) 05306-7].