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First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
G. C. Pomraning
Nuclear Science and Engineering | Volume 69 | Number 1 | January 1979 | Pages 6-13
Technical Paper | doi.org/10.13182/NSE79-A21279
Articles are hosted by Taylor and Francis Online.
Analytic estimates are given for the angular dependence of the neutron (or photon) flux in toroidal geometry arising from the toroidal character of the configuration. The model used in the analysis is the one-group homogeneous diffusion model The toroidal angular effects in the local flux are shown to be first order in ϵ, the inverse aspect ratio, whereas angular effects occurring in spatial integrals of the flux are found to be of order ϵ2. An analytic expression for the Green's function for diffusion equation in toroidal geometry is given correct to order ϵ2, and typical numerical results are shown. A transformation of the scalar flux is presented that removes all angular dependence from the streaming term in the diffusion equation and removes the angular dependence from the absorption term correct to order ϵ. The overall conclusion reached is that angular toroidal effects are not simply characterized.
