Particle beam therapy device and particle beam therapy device operation method

A particle beam therapy system comprising:

• an accelerator having a deflection electromagnet using a core of a magnetic material, that emits a particle beam after adjusting it to have a given energy;
• an irradiation device that irradiates an irradiation target with the particle beam supplied from the accelerator, according to a shape of the target;
• and
• a control unit that controls the accelerator and the irradiation device in a cooperative manner;
• wherein the control unit is provided with:
• an operation pattern retaining section that retains a plurality of operation patterns each being a pattern of operation to be periodically repeated by the accelerator, said operation patterns having respective operation conditions adjusted to have different times that allow emission of the particle beam, and to cause the deflection electromagnet in the accelerator to have an intended magnetic field intensity even under a presence of a hysteresis of the magnetic material;
• an irradiation condition reading section for a plurality of slices resulting from partitioning the irradiation target in a depth direction, that reads an irradiation condition for each of the slices;
• an operation pattern selection section that selects the operation pattern suitable for each of the slices from among the plurality of operation patterns, on the basis of the irradiation condition read by the irradiation condition reading section;
• and
• a main control section that controls, for each of the slices, the accelerator on the basis of the selected operation pattern and the irradiation device on the basis of the irradiation condition.