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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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Latest News
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.”
S. K. Davis, J. A. De Juren, M. Reier
Nuclear Science and Engineering | Volume 23 | Number 1 | September 1965 | Pages 74-81
Technical Paper | doi.org/10.13182/NSE65-A19260
Articles are hosted by Taylor and Francis Online.
Measurements of the shape of the fundamental mode of a thermalized neutron pulse in graphite for rectangular stacks has yielded a value of the extrapolation length, d = 1.825 ± 0.025 cm. The pulsed-neutron decay constants in graphite have been measured over a buckling range from 1.946 × 10−3 to 1.230 × 10−2 cm −2 and fitted to three- and four-term power series in the buckling. To fit points at bucklings greater than 6.0 × 10−3 cm−2, a cubic fit is necessary. An iterative method of fitting the decay constants results in an extrapolation length of 1.78 ± 0.01 cm. The diffusion constant was (2.0896 ± 0.0093) × 105cm2/sec, and the diffusion cooling constant was (3.77 ± 0.35) × 106 cm4/sec at a density of 1.689 g/cm3. A technique of correcting the decay constants for the effect of spectral cooling has been developed. The decay constants corrected to room temperature can be fitted as a linear function of the buckling. This method interates on the heat-transfer coefficient, γ, and gives a value of γ = 1633 ± 89 sec−1 for graphite. The heat-transfer coefficient relates the rate of energy transfer from a moderator to a cooled-neutron spectrum. With this approach the entire buckling range can be fitted with three parameters.