Speaker
Description
Antimony-124 (¹²⁴Sb) is a promising radionuclide for medical applications, particularly in low-dose rate intravascular brachytherapy (IVBT), due to its unique nuclear characteristics. High-energy β-particles (1-2 MeV and higher) are effective for local tumor or restenosis treatment. Low-energy γ-rays (20–300 keV) are suitable for imaging, dosimetry, and monitoring the treatment process without significant deep tissue penetration. Researches indicate that it can be successfully used to prevent recurrent restenosis of blood vessels, which accrue after invasive angioplasty.
We investigated proton-induced nuclear reactions on enriched tin 124Sn (91.9%). The cross-sections were measured up to an energy of 18 MeV using the stacked-foil activation technique. The measurements were performed at the CYCLON 18/18 cyclotron in Yerevan, Armenia.
Besides measuring the production cross-section of the 124Sb isotope (T1/2 = 60.2 d), formed in the 124Sn(p,n) reaction, we also measured the cross sections of the reactions 124Sn(p,pn)123mSn (T1/2 = 40.06 min) and 124Sn(p,3n)122Sb (T1/2 = 2.72 d). The excitation function of the 124Sn(p,n)124Sb reaction has a maximum at 8–9 MeV, and the influence of the 122Sb impurity can be easily avoided by choosing an initial beam energy of less than 16.96 MeV. The co-produced 123mSn isotope is short-lived.
However, the presence of a small impurity (2.4%) of the 122Sn isotope in the target material resulted in a strongly pronounced gamma line at 158 keV (the interference line of 117mSn (T1/2 = 13.61 d), 117Sb (T1/2 = 2.8h), 117mIn (T1/2 = 1.94 h), and 117gIn (T1/2 = 43.8 min). Therefore, the isotopic purity of the target is critical for the production of 124Sn.
