|Budget Amount *help
¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1997 : ¥1,100,000 (Direct Cost : ¥1,100,000)
This research project aims to grow super-high energy sinchillator CeF_3 system doped with rare earths and to investigate fundamentally physical properties of them. The CeF_3 is one of the most promising sinchillators in recent years. We prepared various probable inorganic crystals ; mixed crystals, rare earth doped crystals about CeF_3 and other related sinchillators. In first year, we purchased newly SIT (Electro-Static Induction Transister)-inverter for efficiently induction heating, and succeeded the growth of a very high-quality CsI and CsI : Eu crystals that was a measure of high-energy sinchillator crystal growth. In second year, we established measurement systems of optical detection of magnetic resonance, in which we purchased necessary magnetic resonance cavity attached with optical window and hand-made other optical and magnetic accessories. Irradiation testings were carried out for CeF_3, CsI,CsI : Eu, SrF_2 BaF_2 and their mixed crystals under gamma-ray of 10^6 to 10^8 rad in absorbed dose by ^<60>Co ray source in Tokyo Metropolitan Industrial Techniques Center where is located near our University. Anti-radiation abilities and identifications of generated color centers were investigated by optical and opt-magnetical procedures. For publication, we presented papers ; "Radiative to Non-radiative Processes for Luminescence of Eu^<2+> ion in SrF_2-BaF_2 Mixed Crystals", "lattice Mismatchings in SrF_2-BaF_2 Mixed Crystal Systems Monitored by Eu^<2+> Dopants", "Space Charge Relaxation and Clustering in Yttrium Doped BaF_2" and other related conference papers. A paper about luminescence spectra by X-ray excitation investigated on the Eu^<2+> ion doped into the fluorite-type Ca_<1-x>Sr_xF_2 and Sr_<1-x>Ba_xF_2 mixed crystal systems is submitted by a journal. We pulished also a few papers about high-conversion solar cells for applications of inorganic crystals doped with rare earths.