HIGHLY ENRICHED ISOTOPE SAMPLES OF URANIUM AND TRANSURANIUM ELEMENTS FOR SCIENTIFIC INVESTIGATION

The paper describes the production of highly enriched isotopes of uranium, plutonium, americium and curium by electromagnetic separation for scientific and applied researches in physics, chemistry, geology, medicine, biology and other fields. Using the equipment described, the isotopes are produced in quantities sufficient to set up nuclear physical experiments, to produce nuclear reference materials and standard sources for calibration of radiometrical and mass spectrometrical equipment, in radionuclide metrology, etc. For the following isotopes the indicated degrees of isotopic enrichment were achieved: U-233 - 99.97%; U-235 - 99.97%; U-236 - 98.0%; U-238 - 99.997%; Pu-238 - 99.6%; Pu-239 - 99.9977%; Pu-240 - 99.9-100%; Pu-241 - 96.998%; Pu-242 - 97.8-99.96%; Pu-244 - 96.7%; Am-241 - 99.6%; Am-242m - 73.6%; Am-243 - 99.2-99.94%; Cm-243 - 99.99%; Cm-245 - 99.998%; Cm-246 - 99.8%; Cm-247 - 90%; Cm-248 - 97%. Methods for preparing layers of highly enriched isotopes on various substances are presented: - electrochemical deposition of transuranic elements from aqueous-organic and organic media and vacuum spraying; - the method of foil and coating formation via compounds in the vapour phase; - the method of fabrication of layers of transuranic elements on superthin (1-2-mu-m) metal substrates with additional isolating polymer-metal coatings (0.2-0.4-mu-m), that substantially decrease material transfer from the active layer and increase safety of product handling.