Continuous thin diamond film and its production

PURPOSE: To obtain a continuous thin polycrystalline diamond film useful as an X-ray spectral window having a large area and an extremely small thickness and a low helium permeability. CONSTITUTION: This continuous thin polycrystalline diamond film has an area larger than about 1 mm 2 , a thickness of less than about 2 microns and a helium permeability lower than about 1×10 -6 sccm/sec/mm 2 . The continuous thin diamond film may be composed to the multilayered continuous diamond films from a microcrystalline diamond layer 14 formed on a substrate 16 and a polycrystalline diamond layer formed on this layer 14. The continuous thin polycrystalline diamond film described above is formed as an X-ray window assembly by mounting the thin diamond film 30 existing on a support grid (e.g. 20) by a sealant 34 into, for example, a disk-shaped aluminum ring 32. COPYRIGHT: (C)1990,JPO