Study on Luminescence of KCl:Eu2+ Crystals after X-ray Irradiation at Room Temperature

Bleaching with the F-light at the excitation bandpass of 20 nm results in the phenomenon that F-centre peak and thermoluminescence (TL) glow peaks due to F-z- and F-centres identically decrease with the F-bleach time, whereas TL glow peak due to F-z-centre only remains almost constant irrespective of its time in the case of that at the excitation bandpass of 5 nm. Analysing the data on bleaching e ff ects, absorption spectrum of X-ray irradiated KCl:Eu2+ crystal has a peak due to F-z-centre approximately within 20 nm of the wavelength 560 nm at F-centre peak. Electrons released from F-z-centres at 370 K and from F-centres at 450 K combine with Eu3+ ions, leading to the excited Eu2+ ions from which the luminescence at 420 nm is emitted.