Ac, La, and Ce radioimpurities in Ac-225 produced in 40-200 MeV proton irradiations of thorium

作者：Engle Jonathan W^*; Weidner John W; Ballard Beau D; Fas**ender Michael E; Hudston Lisa A; Jackman Kevin R; Dry Donald E; Wolf**erg Laura E; Bitteker Leo J; Ullmann John L; Gulley Mark S; Pillai Chandra; Goff George; Birnbaum Eva R; John Kevin D; Mashnik Stepan G; Nortier Francois M

来源：Radiochimica Acta, 2014, 102(7): 569-581.

DOI：10.1515/ract-2013-2179

• Ac-225
• Ac-227
• Ce-139
• Ce-141
• Ce-143
• La-140
• Ba-140
• Alpha-emitting
• Radionuclides
• Radiotherapy
• Proton irradiation
• Thorium

Accelerator production of Ac-225 addresses the global supply deficiency currently inhibiting clinical trials fromestablishing Ac-225's therapeutic utility, provided that the accelerator product is of sufficient radionuclidic purity for patient use. Two proton activation experiments utilizing the stacked foil technique between 40 and 200MeV were employed to study the likely co-formation of radionuclides expected to be especially challenging to separate from Ac-225. Foils were assayed by nondestructive gamma-spectroscopy and by alpha-spectroscopy of chemically processed target material. Nuclear formation cross sections for the radionuclides Ac-226 and Ac-227 as well as lower lanthanide radioisotopes Ce-139, Ce-141, Ce-143, and La-140 whose elemental ionic radii closely match that of actinium were measured and are reported. The predictions of the latest MCNP6 event generators are compared with measured data, as they permit estimation of the formation rates of other radionuclides whose decay emissions are not clearly discerned in the complex spectra collected from Th-232(p,x) fission product mixtures.

• 出版日期2014-7
• 单位Los Alamos; 中国人民解放军空军电子技术研究所