Particle therapy system and method

A particle therapy system comprising:

• a circular accelerator for accelerating a charged particle beam, said circular accelerator including a bending magnet;
• a charged particle beam irradiation apparatus for irradiating the charged particle beam extracted from said circular accelerator to an irradiation target;
• a bending magnetic field strength measuring device for measuring the strength of the bending magnetic field of said bending magnet;
• a radial beam position measuring device for measuring the orbit position of the charged particle beam orbiting within said circular accelerator;
• and
• an energy determination device for determining energy of the charged particle beam orbiting within said circular accelerator after the end of acceleration of the charged particle beam by said circular accelerator and before extraction of the charged particle beam from said circular accelerator, and wherein said energy determination device determines the energy of the charged particle beam orbiting within said circular accelerator based on the strength of the bending magnetic field of the bending magnet measured by said bending magnetic field strength measuring device after the end of the acceleration and the orbit position of the charged particle beam measured by said radial beam position measuring device after the end of the acceleration.

A particle therapy system comprising:

• a circular accelerator for accelerating a charged particle beam, said circular accelerator including a cavity for applying a radio frequency wave to accelerate the charged particle beam, and a bending magnet;
• a charged particle beam irradiation apparatus for irradiating the charged particle beam extracted from said circular accelerator to an irradiation target;
• a bending magnetic field strength measuring device for measuring the strength of the bending magnetic field of said bending magnet;
• a frequency counter for measuring the frequency of said radio frequency wave applied by said cavity to accelerate the charged particle beam or the revolution frequency of the charged particle beam orbiting within said circular accelerator;
• and
• an energy determination device for determining energy of the charged particle beam orbiting within said circular accelerator after the end of acceleration of the charged particle beam by said circular accelerator and before extraction of the charged particle beam from said circular accelerator, and wherein said energy determination device determines the energy of the charged particle beam orbiting within said circular accelerator based on the strength of the bending magnetic field of the bending magnet measured by said bending magnetic field strength measuring device after the end of the acceleration and the frequency of the radio frequency wave or the revolution frequency of the charged particle beam measured by said frequency counter after the end of the acceleration.

A method of extracting a charged particle beam comprising the steps of:

• accelerating a charged particle beam within a circular accelerator;
• determining energy of the charged particle beam orbiting within said circular accelerator after the end of acceleration of the charged particle beam by said circular accelerator and before extraction of the charged particle beam from said circular accelerator;
• and
• extracting said charged particle beam from said circular accelerator after completion of said energy determination, and wherein said energy determination is carried out based on a frequency of a radio frequency wave applied for accelerating the charged particle beam by an accelerating cavity provided to said circular accelerator, or a revolution frequency of the charged particle beam orbiting within said circular accelerator, and an orbit position of the charged particle beam orbiting within said circular accelerator, the frequency of the radio frequency wave or the revolution frequency of the charged particle beam orbiting within said circular accelerator and the orbit position of the charged particle beam orbiting within said circular accelerator used for the energy determination being the value measured after the end of the acceleration.

A method of extracting a charged particle beam comprising the steps of:

• accelerating a charged particle beam within a circular accelerator;
• determining energy of the charged particle beam orbiting within said circular accelerator after the end of acceleration of the charged particle beam by said circular accelerator and before extraction of the charged particle beam from said circular accelerator;
• and
• extracting said charged particle beam from said circular accelerator after completion of said energy determination, and wherein said energy determination is carried out based on a strength of a bending magnetic field of a bending magnet provided to said circular accelerator and an orbit position of the charged particle beam orbiting within said circular accelerator, the strength of the bending magnetic field of the bending magnet and the orbit position of the charged particle beam orbiting within said circular acceleratator used for the energy determination being the values measured after the end of the acceleration.

A method of extracting a charged particle beam comprising the steps of:

• accelerating a charged particle beam within a circular accelerator;
• determining energy of the charged particle beam orbiting within said circular accelerator after the end of acceleration of the charged particle beam by said circular accelerator and before extraction of the charged particle beam from said circular accelerator;
• and
• extracting said charged particle beam from said circular accelerator after completion of said energy determination, and wherein said energy determination is carried out based on a strength of a bending magnetic field of a bending magnet provided to said circular accelerator and a frequency of a radio frequency wave applied for accelerating the charged particle beam by an accelerating cavity provided to said circular accelerator, or a revolution frequency of the charged particle beam orbiting within said circular accelerator, the strength of the bending magnetic field of the bending magnet and the frequency of the radio frequency wave or the revolution frequency of the charged particle beam orbiting within said circular accelerator used for the energy determination being the values measured after the end of the acceleration.