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	*Optically & Thermally Stimulated Luminescence (OSL & TL) Group* in *Gaziantep University* *(TLD Readers)*


	Introduction The Model 3500 TLD Reader provides cost-effective measurements of the radiation dose absorbed by individual TLD elements: ribbon (chips), rods, micro-cubes or powders. The instrument includes a sample drawer for a single element TLD dosimeter, a linear, programmable heating system and a cooled photomultiplier tube with associated electronics to measure the TL light output. The WinREMS Software, which runs under Windows on a separate computer, provides the user interface, the reader control and the applications software. The manually operated Model 3500 finds applications in medical physics and dosimetry laboratories.
	Model 3500 Key Features Planchet heating incorporates welded thermocouple for best temperature reproducibility Heating profile includes pre-heat and post-read anneal cycles, with editing Heating temperature capability up to 600°C 7 decade glowcurve acquisition range Thermoelectric PMT cooler for maximum gain stability Measurement quality assurance Automatic background subtraction capability Easy to operate, service and maintain Compact and attractive; 320 mm wide x 290 mm deep x 290 mm high Optional calibration software Optional neutral density filter to extend the high measurement range
Advantages of a Separate Computer Minimum initial investment Extremely flexible parametric adjustments, implemented in software The computer can be used for other purposes when not required for TLD Use of commercial software for data manipulation, report generation and storage Applications Radiotherapy planning verification Total Body Irradiation dose verification Skin irradiation dose verification Stereotactic beam output factor measurement Critical organ dose verification Diagnostic dose studies CT dose measurement for quality assurance Environmental dosimetry Testing for irradiated food Radioactive dating	Dosimetry Performance using LiF; Mg, Ti hips (TLD-100) Radiations measured: Photon, energies > 5 keV Neutron, thermal to 100 MeV Electron/beta, energies > 70 keV Range: 10 µGy to 1 Gy (1mrad to 100 rad) linear 1 Gy to 20 Gy (100 rad to 2000 rad) supralinear Tissue equivalence: < 20% in 3 months without thermal treatment < 5% in 3 months using preheat or glow curve deconvolution Batch uniformity: +/- 15% Std. Dev. from the batch mean, tighter on special request Residual TL signal: < 0.2% of reading, over the range, without anealing Repeatability: for 1 mGy (100 mrad) 137Cs doses, < 2% Std. Dev. of 10 sequential measurements Reuse: more than 500 per dosimeter with < 10% sensitivity charge Threshold: <10 µGy (1 mrad) based on 2.26 Std. Dev. of 10 repeat readings of an unexposed dosimeter
Available Dosimeters For a listing of available dosimeters, click here. Recessed planchets for chip sizes 3.2mm x 3.2mm, 6.4mm x 6.4mm, 15.7mm round Chip and Rod planchet 3.2mm x 3.2mm chip and 6mm rod, 1mm dia. or 1mm sq. Accessories Personal Computer Printer N2 gas flowmeter 2210 Tabletop Irradiator Low temp annealing oven High temp annealing oven Programmable annealing oven Uninterruptable power supply Vacuum tweezers Dosimeter storage tray Stainless steel annealing tray assembly Stainless steel annealing tray	STANDARD FUNCTIONS PERFORMED BY WinREMS SOFTWARE Graphical user interface Pull-down menus Selection via mouse TL data acquisition parameter selections Application of Reader Calibration Factor, (RCF), and Element Correction Coefficient, (ECC) Automatic background subtraction Application of quality factor Raw data and glowcurve printing during acquisition ASCII export file generation Periodic PMT testing of noise and response to test light Alarm and stop if TL data exceeds preset limit Re-read TLD if TL data exceeds preset limit
TLD heating profile setup Selection of pre-defined Time/Temperature Profiles (TTPs) Editing of: TTP titles, Region of Interest (ROI) limits, Calibration region, Preheat temperature and time, Maximum read temperature, Temperature ramp rate, Anneal temperature and time, Acquisition time	TL data acquisition Acquisition of glowcurve Acquisition of temperature profile
TL data presentation and storage Reading parameters Date and time of reading Dosimeter identification Graphically presented glowcurve and TTP Integrals of up to four regions of interest Applicable RCF and ECC Background value for subtraction Values of test light and PMT dark current readings Software options Dosimeter calibration software Glowcurve deconvolution	Computer requirements (minimum) Pentium 166 MHz with 32 MB RAM; 40 MB free disk space; CDROM drive CGA color monitor (800 x 600), keyboard and mouse. Windows 95, 98 or NT 4.x One RS232 serial port for connection to Model 3500, one parallel port for printer.