We used the recuperation effect (see also "Recuperation of infrared stimulated luminescence of feldspars" in this issue) for investigating the connection between infrared- and greenlight-stimulated luminescence (IRSL and GLSL) of feldspars by performing a "double-bleach recuperation" experiment. A diode system was used for infrared (IR) stimulation, and a filtered-light unit for greenlight (GL) stimulation. Powdered feldspar samples (2 mg each) of known chemical characterisation from a mineral collection were used. After beta-irradiation with 180 Gy and storage in the dark for several weeks feldspar aliquots were bleached down to a residual level of approximate to% of the initial level, first with IR and subsequently with GL. For both stimulations, detection of the stimulated luminescence was carried out in the near ultraviolet region (around 260-360 nm, peaked at 340 nm). Other aliquots were bleached in reverse order (1st GL, 2nd IR). These bleaching sequences were also applied to recuperation measurements after 30 days storage time under controlled room-temperature conditions. Results of these experiments will be presented and a possible interpretation of the observed recuperation signals in terms of a two-trap optically simulated luminescence model will be given. The different interaction of the traps, depending on the specific feldspar, will be shown. (C) 2000 Elsevier Science Ltd. All rights reserved. [References: 7]
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