STUDIES ON THE EFFECTS OF ENERGY DEPOSITION AND BACKSCATTERED ELECTRONS ON MAGNETIC MEDIA.

Abstract

A knowledge of the energy deposition by high energy electron beams in coatings used for magnetic media is required to begin to understand the limits of line speed. In this report energy deposition curves are calculated for magnetic coatings with thicknesses and densities nominally used for tapes, floppy disks and rigid disks. As a result of the thinness of the coatings, the results show that most of the dose available for the electron beam cure is deposited in the Al-Mg or Mylar substrates. Experiments also presented on electron backscattering show that the dose administered to the film may be increased by placing a metal substrate with a high atomic number beneath the sample. If the additional dose from backscattered electrons is not sufficient for the desired cure or line speed, then the only resort is to dramatically decrease the incident beam voltage.