[en] Using the new technology described for electrodeposition of elemental thallium-203, zinc-68 and tellurium-124, it was possible to produce simultaneously four targets in each shift. These dense, smooth and homogeneous targets were being able to tolerate high beam currents without loosing or burning enriched material. As a result, radiochemical yields for Tl-201, Ga-67 and I-123 were increased by 22%, 17% and 31% respectively. (author)

[en] The objectives of the present work are to increase thermal stability of cyclotron targets for production of Tl-201 isotope, increase Tl-203 regeneration rate at radiochemical reprocessing of the targets and develop production technology for radiochemical sources based on Rd-103 isotope. Electrochemical coating of copper substrate with Tl increased the beam current at target irradiation from 100 μA to 125 μA. Further increase of the beam current results in sharp decrease of target stability time at irradiation to 15 min at beam current 150 μA. Thermal calculations and tests at the electron-beam stand predict satisfactory stability at such currents. The discrepancy with the irradiation results has not been explained. More accurate specification of regimes for Tl-203 electrochemical recovery from irradiated targets and better matching of the electrolyte composition made it possible to increase the recovery rate up to 99.5%. Before the present Project, the INP had no experience in production of radioactive sources based on Pd-103. Thermo-diffusion extraction of Pd-103 from irradiated rhodium foil has been chosen as a technology-defining method. The process assures good extraction rate and high purity of extracted isotope. Production of Pd-103 sources based on this technology is much simpler compared to the same based on electrochemical processes. (author)

[en] The tellurium-124 target was prepared by electroplating of tellurium-124 on the Ni/Cu target carrier and was irradiated with a proton beam of 25 MeV energy. The loss of the target material was also determined. The overall radiochemical yield was typically greater than 92% and the recovery of ¹²⁴ Te was greater than 99%. The layer of rhodium on the target was prepared by periodic reverse plating. After irradiation of the rhodium target, the electrodissolution and oxidation dissolution method were evaluated and the Molecular plating of Pd-103 onto silver rod was validated in this work. (author)

[en] Research and development for the production of Pd-103 at U-120 Cyclotron in Bucharest was undertaken based on demand of two hospitals in Bucharest interested in brachytherapy of prostate cancer using Pd-103 seeds. The work done during three year project activity has been focused on design and adaptation of dedicated beam line at NIPNE-HH U-120 Cyclotron for experiments of Pd-103 production. Experiments were conducted to obtain nuclear data to find optimal parameters of target irradiation. Post irradiation characterization of the radionuclides activated in target was performed as well. The results obtained are promising and will be developed further in the next two years in the frame of a national research program for implementation of brachytherapy of prostate cancer with Pd-103 seeds. (author)

[en] This work was done in the frame of the research program of 'Standardized High Current Solid Targets for Cyclotron Production of Diagnostic and Therapeutic Radionuclides' co-ordinated by the International Atomic Energy Agency. The aim of the work was to collect, evaluate and calculate cross-section data for proton and deuteron induced reactions on stable isotopes of tellurium, rhodium and palladium in order to produce iodine, palladium and thallium radionuclide respectively for diagnostic and therapeutic purposes. A simple calculation tool was developed to estimate the amount of different radionuclide produced during proton or deuteron bombardment of targets with different enrichments. Using tabulated yield information absolute and relative activity can be calculated for any valid input parameters. (author)

[en] The aim of the present work was to design and build a solid target device with remote control system to be used on the proton beam with the energy of about 15 MeV to produce iodine-123 (124) via p,n reaction with an enriched tellurium-123 (124). It has a motor drive for target compressing. The control system is based on microcontroller and interface converter RS485. It is being used to control water and helium cooling, target compressing and dropping it into the container. The test of the system operation was successful. (author)

[en] Solid targets development aims to obtain large quantities of radionuclides from accelerators. ²⁰¹Tl is the most used radioisotope in nuclear medicine, which is produced in cyclotron. The scope of the research was to test another procedure of Tl-201 production as an alternative of the precipitation and extraction method used at present. Utilization of ionic exchange resins was studied. Pd-103 is increasingly used in brachytherapy seeds. A high current solid target technique for cyclotron irradiation of electroplated metals was developed to produce Tl-201 and Pd-103. The design of the solid target set up and different procedures to obtain Pd-103 for seeds applications are presented. (author)

[en] A new technology for the industrial preparation of high quality Tl-203 cyclotron targets was developed. It consists of ac-constant current electrodeposition of Tl-203 from an alkaline (pH> 12) EDTA plating solution containing appropriate amounts of an anodic depolarizer (hydrazine) and of non-incorporated neutral wetting agent (BRIJ-35). As plating waveform a bipolar chopped sawtooth (f_ST=100 Hz, f_CH = 100 Hz) is applied while the optimum current density equals 2-3 mA.cm^-2. When plating up to 50% depletion is performed, the current efficiency is 100% allowing time-controlled plating of up to eight targets simultaneously. A single plating solution can be reused up to 10 times upon simple addition of the appropriate amount of Tl_2O3 after each batch. (author)

[en] The production of carrier-free Pd-103 solutions by the ¹⁰³Rh(p,n)¹⁰³Pd threshold reaction involves three chemical steps. The first deals with the electroplating of a homogeneous 40-50 μm rhodium layer on a copper target carrier, ensuring to take full benefit of the excitation function during the irradiation in a 6 deg. beam/target geometry. After irradiation the second step involves the dissolution of the irradiated rhodium, followed by step number 3, the separation of rhodium and carrier-free Pd-103. A cylindrical, graphite centrifugal electro-dissolution mini-reactor was developed. It allows time-controlled solution of rhodium fragments, powder and pieces of foils and wires. Feeding 12 N hydrochloric acid into the system operated at 85 deg. C and 1000rpm rotation speed and applying a 30 amperes ac-current, up to 3 grams of metal are dissolved in 40 ml of acid at 99% solubilization level in less than 3 hours. Carrier-free Rd 103 was separated and extracted using the solvent-solvent method. Three different solvents, aqueous Rh_2O3, Rh₂(SO₄)₃, RhCl₃, were tried for rhodium electroplating and recovery. The results indicate that aqueous Rh₂O₃ works best. To optimize the process, the experiment was repeated for different currents, temperatures, and pHs. With this method, a completely smooth, reflective, and crack-free electroplated layer with a thickness of 120 micrometers was obtained. (author)

[en] This paper presents some common characteristics of all solid targets. The effect of power density in solid targets is explored. The transfer of heat from the target to the water cooled target carrier is examined in terms of the laws of heat transfer which will allow transfer out of the target and into the cooling water. Some common types of solid targets are explored including both internal and external targets. Some possibilities for the extraction of the radioisotopes from the target matrix are presented including physical extraction, chemical extraction or extraction using supercritical fluids. Methods of recovery for the enriched target materials are also presented. (author)