en Radiation Biology Radiation Biology تحقيق بديع Original Research <p><strong>Backgrounds: </strong>Thallium-201 is produced through <i>²⁰³Tl (p, 3n) ²⁰¹pb ²⁰¹Tl</i> reaction by cyclotron. This radioisotope has known as one of the cyclotron radioisotopes which is used for myocardial perfusion in the coronary artery disease, Tl-201 after chemical purification and quality control in the form of ²⁰¹Tl-chlorid is ready to send to the hospitals. </p><p><strong>Materials and methods<i>:</i> </strong>In this work the effect of the proton energy on quality of Tl-201, was studied. Radionucleidic purity was determined by high purity Ge (HPGe) detector Gamma spectrometer, in production time and after one half-life (73h). The targets were coated with Enriched Thallium-203 (97%). </p><p><strong>Results:</strong> The Variation of thickness of targets was 18.3 ± 1.3µm. The different energies of bombardment on quality of Tl-201 and Tl-200, Tl-202, and Pb-203 (as impurity) were studied. The results have shown that optimum energy for proton was 28.5 MeV. </p><p><strong>Conclusion: </strong>The variation energy of bombardment can change the purity of Tl-201 but all results were in the standard range according to the United States Pharmacopoeia (USP) and European Pharmacopoeia. <i>Iran </i><i>. J. Radiat. Res. 2003 1(1): 51 - 54. </i></p> Quality control of thallium chloride, quality of thallium 201, radionuclide purity, thallium 201 51 54 http://ijrr.com/browse.php?a_code=A-10-1-8&slc_lang=en&sid=1 A. Sattari asattari@seai.neda.net.ir 7900319475328460021 7900319475328460021 Yes M. Kamalidehghan 7900319475328460022 7900319475328460022 No B. Shirazi 7900319475328460023 7900319475328460023 No M. Shafie 7900319475328460024 7900319475328460024 No M. Mirzaie 7900319475328460025 7900319475328460025 No