[en] Radiation-induced chemiluminescence (lyoluminescence, LL) of saccharides has been proposed as a method of dosimetry. Its accuracy is highly affected by solvent conditions, such as temperature, oxygen content and acidity. The basic mechanisms controlling LL have been investigated in order to reduce the statistical errors. Singlet oxygen released from disproportionation of peroxyl radicals was proposed as an energy carrier. Two singlet oxygen molecules combine their excitation energy. These collisional pairs are assumed to form the light emission centre. This model is supported by spectral analysis of luminescence emission, but a final decision on the emission process is still pending. The lifetime of singlet oxygen is known to be extended when H₂O is replaced by D₂O. As a consequence, enhanced LL output is expected. Experimental proof of this effect is reported. Consequences for the model of LL in saccharides are discussed. (Author)