[en] The basic assumption of luminescence dating is the equality between the growth curve of OSL generated by the natural radiation and the OSL growth curve reconstructed in laboratory conditions. The dose rates that generate the OSL in nature and in laboratory experiments differ by about ten orders of magnitude. Recently some discrepancies between the natural and laboratory growth curves have been observed. It is important to establish their reasons in order to introduce appropriate correction into the OSL dating protocol or to find a test that allows to eliminate the samples which should not be used for dating. For this purpose, both growth curves, natural and laboratory, were reconstructed by means of computer simulations of the processes occurring in the sample during its deposition time in environment as well as those which occur in a laboratory during dating procedure. The simulations were carried out for three models including one shallow trap, two OSL traps, one disconnected deep and one luminescence center. The OSL model for quartz can be more complex than the one used in the presented simulations, but in spite of that the results show effects of growth curves discrepancies similar to those observed in experiments. It is clear that the consistency of growth curves is not a general feature of the OSL processes, but rather a result of an advantageous configuration of trap parameters. The deep disconnected traps play the key role and their complete filling before the zeroing of OSL signal is a necessary condition of the growth curves' consistency. - Highlights: • Process of OSL growth curve generation in nature and in laboratory was simulated. • Discrepancies between the natural and the laboratory growth curves are observed. • Deep disconnected traps play the key role in growth curve inequality. • Empty deep traps before zeroing of OSL cause the inequality of growth curves.

[en] The methods of optically stimulated luminescence (OSL) measurements used until recently, used optical stimulation with a constant energy and a constant or linearly increased flux of stimulation photons. During such a stimulation the ratio of probabilities of the optical release of electrons from different traps is constant and it is hard to separate the signals of different origins. It was shown recently that advantageous changes of the probability ratio during the OSL experiments, and more information about traps can be obtained by optical stimulation with the increasing stimulation energy. This method, however, needs a strong tuneable light source that supplies a stable flux of photons and because of that it cannot find a wide application. Inducing the appropriate changes of the probabilities of the optical release of electrons from traps by increasing the sample temperature during the optical stimulation with a constant stimulation band do not face such obstacles. Such a stimulation can be realised by means of the standard OSL readers after a slight modification and offers the possibility for direct estimation of optical trap depth. The simulations of the OSL process during linear heating show that the experimental parameters such as the heating rate, the stimulation light intensity and the stimulation energy strongly affect the shape of the OSL curve and can be the very useful tools for the OSL process regulation. By this kind of stimulation one can reach very deep traps that are not detectable by thermoluminescence measurements below 500 °C. The resolution of the OSL signal originating from different traps is remarkable.

[en] In the standard OSL dating procedure, the OSL signal is measured at 125 °C. For quartz samples from bricks the presence of traps responsible for the 160 °C and 200 °C TL peaks has an influence on the OSL process, just like the one for the traps responsible for the 110 °C TL peak. In order to examine the significance of this disturbance for dating results, a series of measurements of D_e was carried out for various temperatures of the OSL readout in SAR protocol. For most samples, significant fluctuations of D_e values were obtained, especially at temperatures above 90 °C. Also the analysis of OSL components carried out for curves obtained at different measurement temperatures shows that the TL traps active up to 200 °C make the OSL process more complex. The measurement at 125 °C does not assure the exclusion of shallow traps from the OSL process. A reasonable solution of this problem may be the choice of temperatures below the range of dominant TL peaks, in the SAR protocol for OSL measurements. - Highlights: • 160 °C and 200 °C TL traps in quartz from brick influence the OSL process at 125 °C. • The D_e from SAR protocol for brick samples depends on OSL measurement temperature. • OSL component analysis for different measurement temperatures is presented. • Lower temperature of OSL readout in SAR protocol for quartz from bricks is suggested.

[en] Quartz is the mineral most commonly used for sediment dating. In dating practice, the optically stimulated luminescence (OSL) of quartz is measured mainly using the stimulation light whose wavelength is 470 ± 30 nm. The parameters of traps active in the OSL process are also determined for this stimulation band. The zeroing of the OSL is the fundamental condition of applicability of the luminescence dating for specific sediment and takes place in sunlight whose spectrum differs significantly from the band 470 ± 30 nm. In order to be able to know the course of OSL process in nature, a wider knowledge of the dependency of the trap parameters on the stimulation band is needed. Here the results are presented for the OSL measurements carried out with different wavelengths of stimulation light. For each stimulation band the components of the OSL signal are determined by the fitting procedure, and in this way the wavelength dependence of an individual component is found. The experiment has been repeated for two temperatures of OSL detection – the room temperature, which corresponds to natural conditions, and for 125 °C, which is the temperature usually applied for OSL measurement in dating. Four OSL components are presented in both experimental series. The values of their optical cross-section changes along with stimulation energy and temperature, as it is predicted by the model of OSL process including crystal lattice vibrations. - Highlights: • Study of the optical cross-section (OSC) values for the components of OSL in quartz. • The measurements for various stimulation energies and two temperatures are presented. • Predictions of the OSL model including the crystal lattice vibrations are confirmed

[en] The dependence of the equivalent dose (D_e) on the temperature used at stimulation when the standard OSL dating protocol (SAR) is applied has been investigated for sediment quartz samples. A considerable change in this value appears in the temperature region from 80 to 140 °C that is known for high complexity in OSL processes in quartz. Our observations suggest that the variation in the obtained results at least partly is caused by the laboratory procedure used when the natural OSL signal is measured. Directions for further investigations concerning this undesirable effect are indicated. -- Highlights: ► Temperature dependence of OSL measurement results in dating protocol for quartz was investigated. ► Intensive variations of this value appear in the temperature region that is normally used in dating. ► First results suggest that the reason of these changes lies in the way of natural OSL measurement