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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.”
Zhang Huanqiao, Liu Zuhua, Ding Shengyue, and Liu Shaoming
Nuclear Science and Engineering | Volume 86 | Number 3 | March 1984 | Pages 315-319
Technical Note | doi.org/10.13182/NSE84-A17560
Articles are hosted by Taylor and Francis Online.
This research was published (in Chinese) in Chin. J. Nucl. Phys., 3, 2, 149 (1981). The average number of prompt neutron and the distributions of prompt neutron number probability P(ν) for spontaneous fission of 240Pu, 242Cm, and 244Cm relative to (252Cf) have been measured using a large gadolinium-loaded liquid scintillation counter with a co-incidence method. The results were (240Pu) = 2.141 ± 0.016, (242Cm) = 2.562 ± 0.020, and (244Cm) = 2.721 ±0.021. The measured distributions of prompt neutron number were fitted with Gaussian curves by a weighted least-squares method. The widths of Gaussian distribution are 1.149 ± 0.047, 1.159 ± 0.074, and 1.175 ± 0.098 for 240Pu, 242Cm, and 244Cm, respectively. These results as well as a previous measurement of spontaneous fission of 252Cf show the linear variation of σ with at the first order of approximation. The data were fitted by a least-squares method, and the result is given by σ = 0.980 + 0.076. This fact demonstrates the trend that the width of the excitation energy distribution of fission fragments increases with the average excitation energy of the fission fragments in the range of nuclides mentioned above.