Abstract: A cesium iodide based scintillation material is obtained exhibiting a low afterglow and high radiation hardness; its preparation method is developed, too.The cesium iodide based scintillation material doped by thallium iodide contains an additional admixture of compound having the general formulaMe.sub.x (CO.sub.3).sub.y,where Me is a cationic admixture,1.ltoreq.X.ltoreq.2,1.ltoreq.Y.ltoreq.5,This material has in its absorption spectrum a stretching vibration band of CO.sub.3.sup.2- -ion about 7 .mu.m and a bending vibration band about 11.4 .mu.m, the absorption coefficient of the latter being from 1.4.multidot.10.sup.-3 to 2.multidot.10.sup.-2 cm.sup.-1.Preparation method of this scintillation material comprises the raw material cesium iodide melting, adding of the activating thallium iodide dope, introduction of cesium carbonate (3.multidot.10.sup.-4 to 5.multidot.10.sup.-3 % by mass) and a sodium salt (3.multidot.10.sup.-4 to 7.5.multidot.10.sup.

Abstract: Method of manufacturing large polycrystalline plates from optical and scintillation materials consists in heating a crystalline blank up to the temperature of 0,5T.sub.melt. <T<T.sub.melt., where T.sub.melt. -melting temperature of the starting material, as well as thermomechanical deformation by means of profiled surface up to the double thickness of the plate to be obtained, after which the blank is deformed again at the same temperature using flat-parallel surface till the specified thickness. Such technology provides the obtaining of large polycrystalline plates of the specified geometrical form with the necessary sizes.