Particle beam transport system, and segment thereof

1. A particle beam transport system comprising:

a main line configured to transport a particle beam generated by an accelerator outward;

a branch line branching from the main line;

irradiation equipments provided at respective ends of the branch line and configured to irradiate a patient with the particle beam,

wherein at least a part of the main line and the branch line is configured as plural segments; and

in each of the segments, constituent components and arrangement of the constituent components are made common, and at least a first bending electromagnet, a focus electromagnet, and a second bending electromagnet among the constituent components are arranged in this order, the focus electromagnet configured to focus an outer diameter of the particle beam by an action of a magnetic field and the bending electromagnet configured to bend a traveling direction of the particle beam by an action of a magnetic field;

beam characteristics of the particle beam of each of the plural segments are substantially equal at both ends.

2. The particle beam transport system according to claim 1 ,

wherein in each of the plural segments a betatron function β (βx, βy) in the orthogonal direction (x, y) of the passing particle beam is equal at both ends.

3. The particle beam transport system according to claim 1 ,

wherein each of the plural segments includes a beam measuring component; and

the beam measuring component is provided at a most upstream portion or a most downstream portion of each of the plural segments.

4. The particle beam transport system according to claim 1 ,

wherein each of the plural segments includes a beam-trajectory correction electromagnet.

5. The particle beam transport system according to claim 1 , further comprising a scatterer provided on the main line between the accelerator and one of the plural segments that is closest to the accelerator,

the scatterer is configured to cause multiple scattering of the particle beam; and

a cross-sectional shape of the particle beam at both ends of each of the plural segments is adjusted to be substantially circular.

6. The particle beam transport system according to claim 1 ,

wherein phase difference of the particle beam between both ends of each of the plural segment is adjusted to be an integral multiple of 180 degrees.

7. The particle beam transport system according to claim 1 ,

wherein the plural segments constitute the respective ends of the branch line and are connected to respective irradiation equipments.

8. A segment of a particle beam transport system that includes a main line transporting a particle beam generated by an accelerator outward, a branch line branching from the main line, and irradiation equipments provided at respective ends of the branch line and configured to irradiate a patient with the particle beam, the segment being used for the particle beam transport system by being connected to at least one segment of same configuration and comprising:

an entrance on which the particle beam is made incident;

a passage through which the particle beam made incident from the entrance advances; and

an exit from which the particle beam having advanced through the passage is emitted,

wherein plural magnets are arranged in such a manner that beam characteristics of the particle beam are substantially equal at the entrance and at the exit,

in the segment, constituent components and arrangement of the constituent components are made common, and at least a first bending electromagnet, a focus electromagnet, and a second bending electromagnet among the constituent components are arranged in this order, the focus electromagnet configured to focus an outer diameter of the particle beam by an action of a magnetic field and the bending electromagnet configured to bend a traveling direction of the particle beam by an action of a magnetic field.