Test of Production of $^{198}$Au Radioisotope by Means of Typical Medical Linear Accelerators Used in Teleradiotherapy

The test of production of the Au-198 radioisotope by means of Varian medical linear accelerators used in teleradiotherapy was carried out. The targets made of the natural gold (100% of the Au-197 isotope) were irradiated with high-energy therapeutic 20 MV X-ray beam. Au-198 was produced in the simple capture reaction Au-197(n, gamma) Au-198. The obtained specific activities in the saturation state are relatively low, not exceeding the value of 510.4 kBq/g, because only the high-energy part of the spectrum of 20 MV X-ray beam covers the energy range of the neutron production cross section. Low activity of the Au-198 radioisotope produced by medical linear accelerators makes this technique not suitable for a massive production of Au-198 for nuclear medicine, but the produced amount of Au-198 is sufficient for laboratory tests of new drugs for possible clinical applications.