Radiochemical separation and purification of non-carrier-added silicon-32

32Si (T 1/2 = 153(19) y) is an extremely rare, naturally-occurring isotope that has been considered as a geochronometer suitable for radiometric dating over the time span from 100 to 1000 years ago – a time span that has proved rather difficult to explore in this manner. Past attempts to determine the 32Si half-life have resulted in a wide range of values possessing significant uncertainties because only low-activity samples could be made available for such measurements. Utilizing the 590 MeV ring cyclotron at PSI, megabecquerel quantities of 32Si have been produced by exposing metallic vanadium discs to high-energy protons in order to induce spallation. A radiochemical separation procedure has been successfully developed and applied to the irradiated discs as part of the SINCHRON project, based on a combination of ion-exchange and extraction resins. The process was shown to be reliable and robust with a high chemical yield. Radiochemically pure 32Si solutions with activity concentrations of up to several kBq/g can be produced to perform individual measurements (AMS, ICP-MS, LSC) for various studies. Thus, a careful redetermination of the 32Si half-life has become feasible to begin the first steps toward the confident implementation of this radionuclide for geochronological purposes.

Radioactivity of some natural and artificial radionuclides in coastal seawater at Ninh Thuan, Ba Ria - Vung Tau and Ca Mau provinces in 2018

Radioactivities of some natural (Ra-226, Th-232, U-238, Po-210) and artificial (Cs-137, Sr-90 and Pu-239,240) radionuclides in coastal seawater at monitoring points of Ninh Thuan, Ba Ria - Vung Tau and Ca Mau provinces were analyzed quarterly in the year of 2018. Radioactivities of Ra-226, Th-232, U-238, and Cs-137 had been determined by simultaneous precipitation method and measured on low-level background gamma spectrometer; the radioactivities of Po-210 and Pu- 239,240 had been analyzed by radiochemical separation method and measured on alpha spectrometer; the radioactivity of Sr-90 had been analyzed by radiochemical separation method and measured on low-level background beta counting system. The ranges of radioactivities of Ra-226, Th-232, U-238, Po-210, Cs-137, Sr-90, and Pu-239,240 were 2.71 ÷ 15.91, 3.45 ÷ 35.93, 3.02 ÷ 21.47, 1.51÷ 6.74, 0.88 ÷ 1.68, 1.08 ÷ 1.86 and 0.0026 ÷ 0.0062 mBq/L, with the average values of 6.37, 12.67, 8.34, 3.29, 1.36, 1.46 and 0.0043 mBq/L, respectively. The results shown that the radioactivities of theabove-mentioned radionuclides varied between the seawaters at Ninh Thuan, Ba Ria - Vung Tau and Ca Mau seawater. Additionally, physicochemical parameters in seawater were also surveyed to assess their impact on the fluctuations of the above radionuclides.

A review of accelerator-produced Ga-68 with solid targets

Ga-68 is a positron-emitting nuclide that has recently achieved clinical acceptance as the diagnostic radionuclide in PET tracers used for theranostic studies of Lu-177 labeled therapeutic drugs due to the ease of access provided by Ge-68/Ga-68 generators. An alternative method of production currently being explored uses accelerators to form Ga-68 directly. This review of Ga-68 production strategies discusses available accelerator targetry at a range of beam energies and intensities, the many radiochemical separation techniques available to isolate Ga-68 from irradiated targets, isotopically enriched target material recovery, and the implications of these techniques for downstream radiolabeling applications.

Production of the 103Pd via Cyclotron and Preparation of the Brachytherapy Seed

This study will briefly explain the production of 103Pd via cyclotron for brachytherapy use. The excitation functions of 103Rh(p,n)103Pd and 103Rh(d,2n)103Pd reactions were calculated using ALICE/91, ALICE/ASH, and TALYS-1.2 codes and compared with published data. Production of 103Pd was done via 103Rh(p,n)103Pd nuclear reaction. The target was bombarded with 18 MeV protons at 200 μA beam current for 15 h. After irradiation and radiochemical separation of the electroplated rhodium target, at the optimum condition, 103Pd was absorbed into Amberlite®IR-93 resin. The preparation of the brachytherapy seed, which is loaded by the resin beads, has also been presented. At least, the method to determine the dosimetric parameters for the seed by experimental measurement has been presented.