Study of Thermoluminescence of F-centers

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: 3½ digit 7-segment LED
(4) Nanoammeter, Model DNM-121
      Range: 100nA to 100mA full scale in 4 ranges
      Accuracy : 0.2%.
      Display: 3½ digit 7-segment LED

Complete in all respect, only X-ray facilities are required to create F-centers in the crystal.