Speaker
Dr
Bernhard Scholten
(Forschungszentrum Juelich GmbH, Germany)
Description
The radionuclide 193mPt (T1/2 = 4.33 d) decays by highly converted isomeric transition emitting about 33 Auger electrons. It is of great potential interest in internal radiotherapy because of its suitable decay properties. So far the specific activity of 193mPt produced has been rather low due to the use of the 192Pt(n,γ)-process at a reactor. The aim of this work was to measure the excitation function of the 192Os(α,3n) reaction. Furthermore, the yield and the specific activity of 193mPt produced was determined.
The dissolution of osmium, its conversion to OsO4 vapor and trapping in KOH solution for electrolytic preparation of thin target samples of highly enriched 192Os on Ni as well as the complete radiochemical separation of radioplatinum including 192Os recovery were optimized.
The excitation function of the 192Os(α,3n) 193mPt reaction was measured up to 39 MeV using the stacked-foil activation technique with 99.65 % enriched 192Os targets at the Brussels Cyclotron. The natTi(α,x) 51Cr reaction induced in Ti foils was used to monitor the incident beam intensity of about 100 nA. After a clean separation of radioplatinum, the radioactivity of 193mPt was measured via X-ray spectrometry using the Pt Kα1 X-ray line of 66.8 keV. The cross section of the 192Os(α,3n) 193mPt reaction reaches a value of about 1.5 b at the maximum at about 35 MeV. It was also calculated theoretically using the compound-precompound nuclear model codes TALYS and STAPRE. The calculated values are consistent with the measured data. The optimum production of the 193mPt radionuclide via this route was found in the range 30-38 MeV; the integral yield of 193mPt amounted to 10 MBq/μAh. Its radionuclidic purity was found to be > 99% and the determined specific activity amounted to 1 GBq/μg Pt, which is by about 103 higher than in reactor production. Thus basic information on the production of high-quality 193mPt for therapeutic application is provided.
Primary author
Dr
Bernhard Scholten
(Forschungszentrum Juelich GmbH, Germany)
Co-authors
Heinz H. Coenen
(INM-5: Nuklearchemie, Forschungszentrum Jülich, D-52425 Jülich, Germany)
Md. Shuza Uddin
(INM-5: Nuklearchemie, Forschungszentrum Jülich, D-52425 Jülich, Germany)
Sandor Sudar
(Institute of Experimental Physics, Debrecen University, H-4001 Debrecen, Hungary)
Syed M. Qaim
(Forschungszentrum Jülich)
alex hermanne
(Vrije Universiteit Brussel)