Neue lichtstarke Anordnungen für photochemische Reaktionen

New arrangements for photochemical reactions of substances with active absorption especially in the short wavelength region of the ultraviolet spectrum are described. As light sources are used water cooled high pressure mercury lamps and new xenon arc lamps. The water cooled annual cylindrical vessels containing the photochemical substances are made of fused quartz or special glasses with adapted transmission in the ultraviolet spectrum. They surround completely the light sources which can be exchanged very easily. In this way energy losses of u.v.-radiation and heating of the photochemical substances are avoided, so that best efficiencies can be reached in less than the tenth of the time needed before. This could be confirmed in various photochemical reactions i. e. with vitamin D2 and chlorination of benzene.