Probable nuclear reactions to produce proton rich rhenium radionuclides

Production and separation of no-carrier-added 181−184Re radioisotopes from proton irradiated tungsten target

Cross sections for the production of 181−184Re isotopes from proton irradiated thin natWO3 target at 20.9, 17.9, 14.9, 11.9 and 8.8 MeV projectile energies have been measured. An acceptable agreement between experimentally obtained data and available literature reports was found. The produced no-carrier-added (NCA) Re radionuclides have been separated from bulk tungsten target by liquid-liquid extraction (LLX) using trioctyl amine (TOA) and di-(2-ethylhexyl)phosphoric acid (HDEHP) dissolved in cyclohexane. A clear separation has been observed at 0.1 M and 1 M TOA with 0.1 M HNO3 concentration. However, by using HDEHP NCA Re radionuclides could not be separated from bulk W target without its contamination.

Investigation of activation cross-section data of proton induced nuclear reactions on rhenium

In the frame of systematic investigations of activation cross-section data for different applications the excitation functions of (nat)Re(p,x)(185)Os, (183m)Os, (183g)Os, (182)Os, (181m)Os, (186g)Re, (184m)Re, (184g)Re, (183)Re, (182m)Re, (182g)Re and (181g)Re reactions were measured up to 70MeV. The data for the (nat)Re(p,x) (183m)Os, (183g)Os, (182)Os, (181g)Os,(186g)Re, (184m)Re,(182m)Re, (182g)Re, and (181)Re reactions are reported for the first time. The activation method, the stacked foil irradiation technique and γ-spectroscopy for activity detection were used. The experimental data were compared with predictions of three theoretical codes. From the measured cross-section thick target integral yields were also calculated and presented.

Application of PEG based aqueous biphasic systems in extraction and separation of no-carrier-added 183Re from bulk tantalum

No-carrier-added (nca) rhenium isotopes (182,182m,183Re) were produced by irradiation with 30 MeV α particles on natural tantalum target. The short-lived 182,182mRe were allowed to decay and long-lived nca 183Re was separated from bulk tantalum matrix by aqueous biphasic system (ABS) using 2 M solutions of nine different salts, namely, Na2SO4, Na2SO3, NaHSO3, Na2S2O3, Na2HPO4, Na2CO3, Na-citrate, Na-tartrate, and (NH4)2SO4 as salt rich phases against 50% (w/w) PEG-4000 as polymer rich phase at room temperature. The influence of temperature and thermodynamic parameters Δ Hº and Δ Sº were obtained for the partition of 183Re and tantalum in these systems. Nca 183Re was extracted in high amount in polymer rich phases irrespective of the salt rich phases. Bulk tantalum showed tendency to remain in salt rich phases. ABSs with PEG-4000 polymer rich phase in combination with Na2SO4, Na2SO3, NaHSO3, Na2HPO4, Na2CO3, Na-citrate and Na-tartrate as salt rich phases at basic pH and at ambient temperature (27 ºC) offered single-step separation between nca 183Re and bulk Ta. When Na2S2O3 and (NH4)2SO4 were used as salt rich phase, slight extraction of bulk tantalum was observed in PEG-4000 rich phase. The dynamic dissociation constant of 183Re-PEG-4000 complex was measured by dialysis of the PEG-rich phase against de-ionised water. The k dissociation value was found as low as 0.0185 min−1. Therefore, it is possible to have pure 183Re in de-ionized water immediately after the dialysis.