The baffles we will use for GEO600 will consist of a conical part (blue in the picture below) and a cylindrical part (light green) forming an angle of 25.7 degrees. The total width of a baffle is 14 cm, giving a height of about 3 cm. The surfaces of the baffle will be blackened with an commercial oxidizing stuff called Ebonol (from the japanese company: Enthone-Imasa, German representative: Enthone-Imasa Germany, 40699 Erkrath, Niermannsweg 3-5) to give sufficiently low back-scatter and reflection. The backscatter measured is about 0.1 -1% /sterad depending on the surface roughness of the stainless steel. A direct reflex is not detectable. The multiple reflections at the baffles' blackened surfaces, necessary for the light to return to the mirror will thus sufficiently reduce it's amplitude.
A Maple file for the calculation of the baffle positions.
