Production of 166Ho and 153Sm using hot atom reactions in neutron irradiated tris(cyclopentadienyl) compounds

The behavior of a recoiled 166Ho and 153Sm resulting from the reactions 165Ho(n,gamma)166Ho and 152Sm(n,gamma)153Sm in the organometallic compounds tris(cyclopentadienyl)holmium (C5H5)3Ho(III), and tris(cyclopentadienyl)samarium (C5H5)3Sm(III) were investigated. Several chemical separation methods were developed for each compound to separate the recoil products from the irradiated compound. Retention value of 0.2 �} 0.1% was obtained for (C5H5)3Ho(III) using sublimation. Another value of retention of 0.4 plus or minus 0.1% resulted when column chromatography was used. Paper chromatography (using Whatman Chr. 1 and Whatman Chr. 4) gave different retention values of about 0.11 plus or minus 0.05%, and 0.4 plus or minus 0.1%, respectively. Similar behavior of 153Sm in irradiated (C5H5)3Sm(III) was found when paper chromatography was used for separation. The different retention values given by different methods of separation were discussed. An important improvement of the specific activity was achieved as compared with other published results in this field. The obtained results pointed out that tris(cyclopentadienyl)holmium and samarium could be used to produce high specific activity of 166Ho and 153Sm in the Syrian low flux miniature nuclear source reactor (MNSR), where the averaged achieved enrichment factor for holmium compound was found to be greater than 1.6 x 107.