DESIGN NOTE: Equipment for electrolytic colouration of alkali-halide crystals and their simultaneous spectral recording

Equipment is described which is used to produce colour centres electrolytically in alkali-halide crystals and to measure their spectra simultaneously using a high-speed spectroradiometer. The colouration process takes place in an inert atmosphere and its progress can be easily followed. A rapid and gentle quenching of the crystal after the colouration is executed by a flow of inert gas. A high-speed spectroradiometer, combined with the furnace, records transmittance spectra of the crystal within a few seconds during the colouration.