Patent Number: 
Section: claims

1. A beam irradiation apparatus comprising:a vacuum-evacuated transport pipe for transporting a beam from an accelerator;a quadrupole magnet on an outer periphery of the vacuum-evacuated transport pipe, and which is configured to control a diameter of the beam by strongly focusing the beam so that the beam is incident on an irradiation target existing in the atmosphere while maintaining a focusing angle of the beam; anda vacuum-evacuated extraction nozzle which is connected, via a vacuum diaphragm, to an end portion of the vacuum-evacuated transport pipe,wherein the vacuum-evacuated extraction nozzle comprises an expanding-contracting section which retractably extends from the end portion of the vacuum-evacuated transport pipe. 2. The beam irradiation apparatus according to claim 1, further comprising one or more longitudinally movable range shifters which are configured to modulate a beam range by reducing energy of the beam by allowing the beam to pass through the one or more longitudinally movable range shifters, andwherein the expanding-contracting section of the vacuum-evacuated extraction nozzle is configured to modulate the beam range by changing a distance of a non-vacuum space between the one or more longitudinally movable range shifters and the irradiation target. 3. The beam irradiation apparatus according to claim 2,wherein the vacuum-evacuated extraction nozzle further comprises an extension section which is continuously connected to the vacuum-evacuated transport pipe and which extends perpendicularly from the vacuum-evacuated transport pipe. 4. The beam irradiation apparatus according to claim 2,wherein each of the one or more longitudinally movable range shifters is adapted to be slidably inserted into the vacuum-evacuated extraction nozzle with respect to a beam axis, to change a combined thickness of the one or more longitudinally movable range shifters. 5. The beam irradiation apparatus according to claim 4, further comprising, on the outer periphery of the vacuum-evacuated transport pipe and on a downstream side of the quadrupole magnet, a pair of X-axis direction scanning electromagnets arranged to face each other, and a pair of Y-axis direction scanning electromagnets arranged to face each other,wherein the pair of X-axis direction scanning electromagnets and the pair of Y-axis direction scanning electromagnets are configured to modulate a trajectory of the beam. 6. The beam irradiation apparatus according to claim 2, further comprising, on the outer periphery of the vacuum-evacuated transport pipe and on a downstream side of the quadrupole magnet, a pair of X-axis direction scanning electromagnets arranged to face each other, and a pair of Y-axis direction scanning electromagnets arranged to face each other,wherein the pair of X-axis direction scanning electromagnets and the pair of Y-axis direction scanning electromagnets are configured to modulate a trajectory of the beam. 7. The beam irradiation apparatus according to claim 1,wherein the vacuum-evacuated extraction nozzle further comprises an extension section which is continuously connected to the vacuum-evacuated transport pipe and which extends perpendicularly from the vacuum-evacuated transport pipe. 8. The beam irradiation apparatus according to claim 7,wherein each of the one or more longitudinally movable range shifters is adapted to be slidably inserted into the vacuum-evacuated extraction nozzle with respect to a beam axis, to change a combined thickness of the one or more longitudinally movable range shifters. 9. The beam irradiation apparatus according to claim 7, further comprising, on the outer periphery of the vacuum-evacuated transport pipe and on a downstream side of the quadrupole magnet, a pair of X-axis direction scanning electromagnets arranged to face each other, and a pair of Y-axis direction scanning electromagnets arranged to face each other,wherein the pair of X-axis direction scanning electromagnets and the pair of Y-axis direction scanning electromagnets are configured to modulate a trajectory of the beam. 10. The beam irradiation apparatus according to claim 1, further comprising, on the outer periphery of the vacuum-evacuated transport pipe and on a downstream side of the quadrupole magnet, a pair of X-axis direction scanning electromagnets arranged to face each other, and a pair of Y-axis direction scanning electromagnets arranged to face each other,wherein the pair of X-axis direction scanning electromagnets and the pair of Y-axis direction scanning electromagnets are configured to modulate a trajectory of the beam. 11. A beam irradiation control method, comprising:strongly focusing a beam in a vacuum-evacuated transport pipe using a quadrupole magnet, the beam having been emitted from an accelerator,modulating a diameter of the beam in increments of 0.1 mm or less, andirradiating the beam onto an irradiation target,wherein strongly focusing the beam in the vacuum-evacuated transport pipe maintains a focusing angle of the beam until the beam reaches the irradiation target. 12. The beam irradiation control method according to claim 11, further comprising:controlling a beam range by passing the beam through one or more longitudinally movable range shifters, and optionally passing the beam through a distance of a non-vacuum space between the one or more longitudinally movable range shifters and the irradiation target,wherein each of the one or more longitudinally movable range shifters is adapted to be slidably inserted into a vacuum-evacuated extraction nozzle which is connected, via a vacuum diaphragm, to the vacuum-evacuated transport pipe,wherein the one or more longitudinally movable range shifters are configured to modulate a beam range by reducing energy of the beam by allowing the beam to pass through the one or more longitudinally movable range shifters, andwherein the distance of the non-vacuum space between the one or more longitudinally movable range shifters and the irradiation target can be changed. 13. The beam irradiation control method according to claim 12,wherein the distance of the non-vacuum space between the one or more longitudinally movable range shifters and the irradiation target is in a range of 0 to 100 cm. 14. A heavy particle radiotherapy apparatus for medical purposes, comprising:a vacuum-evacuated transport pipe for transporting a beam from an accelerator;a quadrupole magnet on an outer periphery of the vacuum-evacuated transport pipe and which is configured to modulate a diameter of the beam by strongly focusing the beam so that the beam is incident on an irradiation target existing in the atmosphere while maintaining a focusing angle of the beam;a vacuum-evacuated extraction nozzle which is connected, via a vacuum diaphragm, to an end portion of the vacuum-evacuated transport pipe and which comprises an expanding-contracting section that retractably extends from the end portion of the vacuum-evacuated transport pipe;one or more longitudinally movable range shifters which are provided at a distal end of the vacuum-evacuated extraction nozzle, each of the one or more longitudinally movable range shifters being adapted to be slidably inserted into the vacuum-evacuated extraction nozzle with respect to a beam axis, to change a combined thickness of the one or more longitudinally movable range shifters; anda pair of X-axis direction scanning electromagnets that face each other and a pair of Y-axis direction scanning electromagnets that face each other, each of the pair of X-axis direction scanning electromagnets and the pair of Y-axis direction scanning electromagnets being arranged on the outer periphery of the vacuum-evacuated transport pipe and on a downstream side of the quadrupole magnet,wherein the one or more longitudinally movable range shifters are configured to modulate a beam range by reducing the energy of the beam by allowing the beam to pass through the one or more longitudinally movable range shifters, andwherein the expanding-contracting section of the vacuum-evacuated extraction nozzle is configured to modulate the beam range by changing a distance of a non-vacuum space between the one or more longitudinally movable range shifters and the irradiation target.