Circular accelerator, particle therapy system with circular accelerator, and method of operating circular accelerator

A circular accelerator that applies a first radiofrequency wave in a main magnetic field in order to accelerate charged particle beam while increasing an orbit radius comprising,

• a radiofrequency acceleration cavity configured to generate the first radiofrequency wave;
• a radiofrequency kicker configured to generate a second radiofrequency wave;
• wherein the second radiofrequency wave has a frequency different from the first radiofrequency wave and is applied in an intensive region of the orbit of the charged particle beam inside the circular accelerator, or on the maximum energy orbit of the charged particle beam in order to extract the charged particle beam,
• wherein the second radiofrequency wave is applied in a direction perpendicular to the orbit in an orbit plane.