Optical absorption and thermoluminescence studies in 100MeV swift heavy ion irradiated CaF2 crystals

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 2011-01, Vol.269 (2), p.185-188
• Main Authors: Pandurangappa, C., Lakshminarasappa, B.N., Singh, Fouran, Nagabhushana, K.R.
• Format: Article
• Language: English
• Subjects: Calcium fluoride; Crystal defects; Crystals; Doped crystals; Fluence; Irradiation; Optical properties; Spectra
• ISSN: 0168-583X
• DOI: 10.1016/j.nimb.2010.10.022

a-[ordm The present paper describes the effect of Ion irradiation on optical properties of CaF2 single crystals. a-[ordm The changes in Optical absorption and TL intensity with increase in ion fluence in both pure and Ytterbium doped CaF2 crystals are explained. a-[ordm The defect centers responsible for the optical absorption are identified. Pure and Ytterbium (Yb) doped Calcium fluoride (CaF2) single crystals were irradiated with 100MeV Ni7+ ions for fluences in the range 5A-1011-2.5A-1013 ionscma degree 2. The irradiated crystals were characterized by Optical absorption (OA) and Thermoluminescence (TL) techniques. The OA spectra of ion irradiated pure CaF2 crystals showed a broad absorption with peak at a arrow right 4556nm and a weak one at a arrow right 4220nm, whereas the Yb doped crystals showed two strong absorption bands at a arrow right 4300 and 550nm. From the study of OA spectra, the defect centers responsible for the absorption were identified. TL measurements of Ni7+ ion irradiated pure CaF2 samples indicated a strong TL glow with peak at a arrow right 4510K. However, the Yb doped crystals showed two TL glows at a arrow right 4406 and 496K. The OA and TL intensity were found to increase with increase of ion fluence upto 1A-1013 ionscma degree 2 and thereafter it decreased with further increase of fluence. The results obtained are discussed in detail.