Comparison of experimental and modelled quartz thermal-activation curves obtained using multiple- and single-aliquot procedures

This paper presents the results of a broad study of the thermal-activation characteristics of three quartz samples of different origin. The thermal-activation characteristics of synthetic, sedimentary and Arkansas quartz are measured as a function of several experimental parameters and over the temperature range 20 - 500 ^{{ring operator}} C using both multiple-aliquot and single-aliquot techniques. The studies are carried out also as a function of the thermal preparation of the samples, for "as-is" samples, for samples fired at temperatures of 500 and 900 ^{{ring operator}} C. Additional experimental parameters varied in this study include the test dose used in measuring the thermal activation curves and the temperature interval between successive heating of the samples. The results of this experimental study for all three quartz samples are interpreted by using a simple modified Zimmerman model for quartz consisting of 2 electron traps, a luminescence center and three hole reservoirs. The results are also discussed within the recently published complex theoretical quartz model by Adamiec (2005. Investigation of a numerical model of the pre-dose mechanism in quartz. Radiat. Meas. 39, 175-189), which is based on a luminescent center, three electron traps and three reservoir hole traps.