Development of an Electron Linac for Radiation Therapy. II. Reduction of Accelerating Field Strength, Improvement of Accelerating Structure Efficiency

The second part of the article on the development of an electron linac for the radiation therapy complex ‘‘Onyx’’ is devoted to solving problems associated with the high electric field strength in the accelerating structure, which include high dark currents, a lengthy conditioning process, significant consumption of pulsed RF power for ohmic losses in the structure walls, and its low efficiency. The article outlines the steps we took to reduce the electric field and increase the efficiency of the accelerating structure. The main results of the bremsstrahlung characteristics tests for the final version of the accelerating structure are presented.