Uniform Irradiation of Thin Films

In film materials with a thickness less than the electron range, the peak of the depth–dose curve is lower and closer to the front surface compared to thick films. During electron beam processing of thin films, dose nonuniformity of ±5 to ±20% can be achieved by using auxiliary front and back inserts. The front insert is used to control the minimum dose in the target, while the back insert is used to control the maximum dose. Diagrams are presented for determining the optimal target thickness and auxiliary inserts for single- and double-sided irradiation and electron energies from 0.4 to 5 MeV.