Photoluminescence of crystallophosphors for the determination of 237Np and 239Pu

The photoluminescence of crystallophosphors, activated by neptunium and plutonium has been studied in connection with the necessity of discovering and elaborating on new analytical methods for actinides determination. Crystallophosphors on the base of fluorides, molybdates and tungstates have been prepared by introducing neptunium and plutonium solutions into the powder matrix, further drying and blend calcination. Luminescence spectra at room temperature have been found to have some broad bands in the near i.r. region independently of the method of crystallophosphor preparation, the oxidation state of introduced elements and the conditions of u.v. irradiation. The effect of matrix nature, flux content and concentration of quenching elements in analyzed solution on crystallophosphors luminescence has been studied. The methods of neptunium and plutonium determination, including their common presence have been worked out. Using the crystallophosphor based on lead molybdate it is possible to determine in the same sample besides neptunium at 1713 nm, also plutonium at 1986 nm, as well as uranium at 507 nm. The method can be applied to the analysis of complex solutions without chemical isolation and concentration of the elements studied. (author)