Simulation of mechanical properties of diamond membrane for application to electron beam extraction window

The use of diamond as the extraction window membrane for electron beam (EB) irradiation systems has been investigated by preliminary experiments and static simulations. The EB transmission characteristics of a fabricated 1.1 μm thick poly-crystalline diamond membrane were evaluated. A very high EB transmittance was observed, up to 70% at a 28 KeV accelerating voltage. Static simulations of EB extraction through a diamond membrane with a Si support have been carried out, under conditions from vacuum to atmosphere. Compared with Si, diamond/Si suffers a higher stress and strain, but, the displacement of a diamond film is much smaller. These results form a basis for the application of thin film, nanocrystalline and ultranano crystalline diamond on Si in the realization of the next generation miniature EB irradiation systems.