High flux isotope reactor target

Os-191 is produced by neutron irradiation of isotopically enriched 0s-190 (isotopic composition 0s-190, 97.8 o Os-188, 0.47 o Os-192, 1. 02 o). Irradiations are currrently performed at the Oak Ridge National Laboratory in the High Flux Isotope Reactor (HFIR) at a neutron flux of 2.5 x 10 n/cm -s. The routes to the various nuclides produced during irradiation of the 0s-190 target and the neutron cross-section values (2 ) are summarized below (Scheme I). 

Sease, J. D. "The Fabrication of Target Elements for the High-Flux Isotope Reactor," ORNL-TM-1712 (1967). 

Production of from a W target in the Oak Ridge High Flux Isotope Reactor (HFIR) and the... 

Transuranium elements are artificially created. The (n, y) reaction, first used successfully for the production of neptunium (Z = 93), works only up to fermium (Z = 100). It ends at Fm due to the short half-life of this isotope (e.g., Seaborg and Loveland 1990). With neutron irradiation, transuranium elements can be produced in weighable amounts by breeding in high flux reactors because the cross sections are of the order of barns, neutron fluxes are high, and the usable target thickness is large. 

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