A CLOSED EXPRESSION FOR BEAM HEATING OF THIN-FILMS

When an electron beam passes through a thin film, it causes the temperature to rise. A simple expression is developed for the temperature rise which occurs at the centre of a circular beam incident on a square thin film whose edges are thermally anchored. Heat loss is assumed to occur by thermal conduction. The axis of the beam may be incident at any point of the film (not only the centre) but the beam should not strike any of the supporting grid bars. A calculation accuracy of less than 1% can be obtained with the use of three coefficients and this can be improved further by the use of additional coefficients which are tabulated. © 1990.