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We offer Study of Thermoluminescence of F-centers, TLX-02 in Alkali Halide Crystals. A colour centre is a lattice defect that absorbs visible light. These colour centers can be produced by heating the crystal in excess of alkali vapour or by irradiation. The colour centers formed due to trapped electrons or trapped holes can be destroyed (bleached) by illuminating with light or warming. Important information about the colour centers can be obtained from the plot of luminescence intensity vs. temperature, taken at a constant heating rate called glow curve. It may contain one or many glow peaks, depending upon whether there are one or several different kinds of traps. The experiment consists of the following: (a) Experimental set-up for creatingvThermoluminescence (1) Sample: KBr (TLS-KBr) and KCl (TLS-KCl) single crystal (2) Thermoluminescence Temperature Meter, TL-02 • Digital Thermometer with RTD sensor • Oven power supply (3) Sample holder (4) Thermoluminescence Oven (upto 423K), TLO-02 (5) Black Box, TL-BBx (b) For measurement of Luminescence Intensity (1) Photomultiplier tube 931A, TL-PMT (2) PMT Housing with biasing circuit and connecting coaxial cables, TL-PMH (3) High Voltage Power supply, EHT-11 (4) Digital Nanoammeter, DNM-121 Complete in all respect, only X-ray facilities are required to create F-centers in the crystal.

We offer Thermoluminescence of F-centres, in this Pure alkali halide crystals are transparent throughout the visible region of the spectrum. The crystals may be colored in a number of ways (1) by the introduction of chemical impurities (2) by introducing an excess of the metal ion (3) by X-ray, γ-ray, neutron and electron bombardment (4) by electrolysis Colour centres produced by irradiation with X-rays When a X-ray quantum passes through an ionic crystal, it will usually give rise to a fast photo-electron with an energy of the same order as that of the incident quantum. Such electrons, because of their small mass, do not have sufficient momentum to displace ions and therefore loose their energy in producing free electrons, holes, excitons and phonons. Evidently these while moving near the vacancies form trapped electrons as well as trapped holes. The trapped-electron or trapped-hole centres so formed can be destroyed (bleached) by illuminating the crystal with light of the appropriate wavelength or warming it. The experiment consists of the following Experimental set-up for creating thermoluminescence (1) Sample: KBr or KCl single crystal (2) Thermolumniscence Temperature Meter, TL-02 Digital Thermometer Oven Power Supply (3) Sample Holder (4) Thermoluniscence Oven (0-423K) (5) Black Box For measurement of luminescence intensity (1) Photomultiplier tube: 931A (2) PMT Housing with biasing circuit and coaxial cables etc. (3) High Voltage Power Supply, Model: EHT-11 Output : 0-1500V variable (1mA max.) Regulation : 0.05% Display: 3.5 digit 7-segment LED (4) Nanoammeter, Model DNM-121 Range: 100nA to 100mA full scale in 4 ranges Accuracy : 0.2%. Display: 3.5 digit 7-segment LED Complete in all respect, only X-ray facilities are required to create F-centers in the crystal.