Abstract: An antireflection coating having a high abrasion and scratching resistance can be applied to natural glass by sputtering, the substrates being positioned closer to the target than usual in order to obtain an increased density of the applied layers. An irregular deposition rate can be compensated by moving the substrate, thus allowing to ensure a regular thickness and therefore a high optical quality of the antireflection coating in these conditions as well. On the preferred sapphire watch glass, SiO2 and Si3N4 resp. AlN and Al2O3 can be used for the individual layers, in particular. These layers do not have a noticeable color effect, but on account of their high hardness, their abrasion and scratching resistance is comparable to that of sapphire glass.

Abstract: A magnetic field cathode for arc discharge vaporizers is described which has an inner ring coil associated with the target center and at least one outer ring coil associated with the peripheral region of the target, with the inwardly disposed ring coil surrounding a permanent magnet arranged at the center of the target and forming a field line concentrator together with this permanent magnet.