PURPOSE: To obtain a fluorescent substance, having a high sensitivity and capable of increasing the stimulation luminous intensity even if the X ray irradiation dose is same as a conventional one by baking a barium halide fluorescent substance activated with europium according to a specific process.
CONSTITUTION: This method for producing a fluorescent substance is to initially bake a fluorescent substance expressed by the formula BaX2:XEU [X is F, Cl, Br or I; (x) is a numerical value of 0.0001<(x)<0.1], preferably at 300-800°C in an oxidizing atmosphere, then cool the baked fluorescent substance, subsequently bake the resultant fluorescent substance in a nonoxidizing atmosphere, preferably a mixed gas atmosphere of an ammonium halide gas with an inert gas or a hydrogen halide gas with the inert gas, then cool the resultant fluorescent substance and further, as necessary, repeat the two baking steps plural time. In this case, the final step is preferably the baking step carried out in the nonoxidizing atmosphere. Furthermore, the baking in the nonoxidizing atmosphere is preferably performed at 500-1100°C.
IWASE NOBUHIRO
HIDAKA SOICHIRO
