Abstract: Producing a molded body made of opaque quartz glass includes providing SiO2 grains obtained by comminuting quartz glass having a purity of at least 99.9 wt % SiO2, forming a slurry containing a suspension liquid and the SiO2 grains and which has a total solids content, wet grinding the SiO2 grains in the slurry so as to form ground SiO2 grain particles, forming a porous green body from the slurry, and sintering the porous green body. To provide a low cost quartz glass, the wet grinding of the SiO2 grains takes place at least temporarily in the presence of SiO2 nanoparticles, the proportion of which in the total solids content of the slurry is in the range of 0.1 wt % to 10 wt %, and the slurry has a solids content in the range of 76 to 80 wt % after addition of the SiO2 nanoparticles and after the wet grinding.

Abstract: A diffuser material of synthetically produced, pore-containing quartz glass and a method for the manufacture of a molded body consisting fully or in part thereof. The diffuser material has a chemical purity of at least 99.9% SiO2, a cristobalite content of not more than 1%, and a density in the range of 2.0 to 2.18 g/cm3. Starting therefrom, to indicate a diffuser material which is improved with respect to diffuse reflectivity with Lambertian behavior over a wide wavelength range, high material homogeneity and UV radiation resistance, the quartz glass has a hydroxyl group content in the range of at least 200 wt. ppm and at least 80% of the pores have a maximum pore dimension of less than 20 ?m.

Abstract: A diffuser material of synthetically produced, pore-containing quartz glass and a method for the manufacture of a molded body consisting fully or in part thereof. The diffuser material has a chemical purity of at least 99.9% SiO2, a cristobalite content of not more than 1%, and a density in the range of 2.0 to 2.18 g/cm3. Starting therefrom, to indicate a diffuser material which is improved with respect to diffuse reflectivity with Lambertian behavior over a wide wavelength range, high material homogeneity and UV radiation resistance, the quartz glass has a hydroxyl group content in the range of at least 200 wt. ppm and at least 80% of the pores have a maximum pore dimension of less than 20 ?m.