Authors:Yang Weifan, Yuan Shuangui, Xiao Yonghou, and Xu Yanbing
Protactinium was produced by the reaction of 60 MeV/nucleon 18O with natural uranium. A simple, relatively fast radiochemical procedure was developed, which can be used for the extraction separation of protactinium from uranium and from the complex reaction products using 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and tri-iso-octylamine as extractants. Measurements of the gamma-ray spectra for the separated protactinium fractions were performed with a HPGe detector. The measured g-ray spectrum of protactinium shows that the decontamination from the main impurity elements, especially zirconium and niobium, is quite satisfactory.
Authors:S. Lahiri, X. Wu, Yang Weifan, Xu Yanbing, and Yuan Shuanggui
Liquid liquid extraction of 46Sc was studied with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP). It has been found that PMBP extracts almost quantitatively scandium from 10-3 to 10-2M HCl solutions. Tributyl phosphate (TBP) has a pronounced antagonistic effect on the extraction process.
Authors:Xiao Yonghou, Yan Weifan, Yuan Shuanggui, Xu Yanbing, He Janjun, Pan Wiangyan, and Li Yingjun
230Ra and its daughter 230Ac were produced by the reaction of 60 MeV/u 18O with ThO2. Using 133Ba, 224Ra and 212Pb–212Bi as tracers, 0.1M NH4EDTA–0.3M NH4-acetate solution as eluent, the relationship between pH and elution peaks, and the influence of the amount of Ba2+ carrier on the elution curve in cation exchange procedures were tested. Based on the results of conditional experiments, a procedure suitable for isolation of radium from the ThO2 irradiated with 60 MeV/u 18O beam was developed. The results demonstrated that the decontamination effectiveness for main reaction products, specially for barium, was satisfactory.
Authors:Xu Yanbing, Yang Weifan, Yuan Shuanggui, Xiao Yonghou, Pan Qiangyan, and Li Yingjun
Barium isotopes were produced by 60 MeV/u 18O ion bombardment of natural uranium via 238U (18O, X) reactions. Ba sources were prepared by radiochemical separation, and measured by a HPGe detector. The cumulative cross sections were obtained by analysis of measured time sequence g-ray spectra. A double peak phenomenon in Ba isotope distribution was observed.
Authors:Xiong Bing, Yang Weifan, Yuan Shuanggui, Ma Taotao, He Jianjun, Xu Yanbing, and Li Zongwei
A new heavy neutron-rich thorium isotope was produced via a multinucleon transfer reaction by irradiation of natural uranium
targets with 60 MeV/u18O ions. The Th activities was radiochemically separated from the uranium and mixture of reaction products by the rapid solvent
extraction method. Measurements of the gamma-ray spectra were performed with HPGe detectors. The new neutron-rich isotope238Th was identified for the first time based on the observation of the growth and decay of the gamma-ray with energy of 1060.5
keV from the decay of238Pa. The half-life of238Th has been determined to be 9.4±2.0 minutes. Further, a gamma-ray of 89.0 keV with the 8.9-minute half-life was found, which
may be due to the decay of the new isotope238Th.
The solvent extraction behavior of thorium traces from the hydrochloric acid media with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) is described using 234Th as a tracer. The influence of certain variables such as extractant concentration, acidity, equilibrium time as well as UO22+ ions on the extraction of thorium has been investigated systematically. The back-extraction behavior of thorium from the organic phase has also been tested. The results reveal that the percent extraction of 234Th decreases with increasing hydrochloric acid concentration and thorium is easily back-extracted with an 4-6 mol/l aqueous HCl solution. At the same time, the effect of thorium extraction with PMBP was tested employing radioisotopes as multi-tracers in the irradiation of natural uranium with 14-15 MeV neutrons. The results show that thorium can be completely separated from a large amount of uranium and most of the other main reaction products.