Abstract: Provided is a semiconductor device capable of reducing switching loss at turn-off while suppressing conduction loss. An emitter p? layer 11, a collector p layer 23, a drift layer 10, an emitter electrode 18, a collector electrode 28, an emitter-side gate electrode 17, an emitter n layer 12, a collector p? layer 23a, a collector-side gate electrode 27, and a collector n layer 22 configure a semiconductor device 1, and a total length of a first facing region of the emitter-side gate electrode 17 in a gate width direction facing an emitter layer p? 11 via a gate insulating film 15 is longer than the total length in the gate width direction of a second facing region of a collector-side gate electrode 27 facing an impurity layer 23a via a collector-side gate insulating film 25.

Abstract: In a circular accelerator that applies a radiofrequency wave in a main magnetic field to accelerate charged particle beam while increasing an orbit radius, another radiofrequency wave with a frequency different from the radiofrequency wave used for acceleration is applied to the charged particle beam in order to extract the charged particle beam. Thereby, in the circular accelerator that accelerates charged particle beam while increasing an orbit radius by applying a radiofrequency wave in a main magnetic field, the high precision control on extraction of the charged particle beam from the circular accelerator is achieved.

Abstract: In a circular accelerator that applies a radiofrequency wave in a main magnetic field to accelerate charged particle beam while increasing an orbit radius, another radiofrequency wave with a frequency different from the radiofrequency wave used for acceleration is applied to the charged particle beam in order to extract the charged particle beam. Thereby, in the circular accelerator that accelerates charged particle beam while increasing an orbit radius by applying a radiofrequency wave in a main magnetic field, the high precision control on extraction of the charged particle beam from the circular accelerator is achieved.

Abstract: In a circular accelerator that applies a radiofrequency wave in a main magnetic field to accelerate charged particle beam while increasing an orbit radius, another radiofrequency wave with a frequency different from the radiofrequency wave used for acceleration is applied to the charged particle beam in order to extract the charged particle beam. Thereby, in the circular accelerator that accelerates charged particle beam while increasing an orbit radius by applying a radiofrequency wave in a main magnetic field, the high precision control on extraction of the charged particle beam from the circular accelerator is achieved.

Abstract: In a circular accelerator that applies a radiofrequency wave in a main magnetic field to accelerate charged particle beam while increasing an orbit radius, another radiofrequency wave with a frequency different from the radiofrequency wave used for acceleration is applied to the charged particle beam in order to extract the charged particle beam. Thereby, in the circular accelerator that accelerates charged particle beam while increasing an orbit radius by applying a radiofrequency wave in a main magnetic field, the high precision control on extraction of the charged particle beam from the circular accelerator is achieved.

Abstract: First ions and second ions that are heavier than first ions are generated in an ion source. One kind of ions of the first ions and second ions is injected into an accelerator by action of a switching magnet and accelerated in the accelerator. An ion beam including the one kind of ions is extracted from the accelerator to a beam transport system and a tumor volume of a patient is irradiated with the ion beam from an irradiation nozzle. In the irradiation of the ion beam, a tumor volume depth and the largest underwater range of each ion species are compared, and an ion species in which the tumor volume depth becomes the longest underwater range or lower is injected into the accelerator, and accelerated by the accelerator. The tumor volume is irradiated with the ion species.

Abstract: A radiotherapy system acquires an image which is necessary for positioning of a patient for radiation treatment and enables grasping of a positional relationship of a target in a treatment radiation irradiated state, a radiation passing area and a critical organ. An X-ray imaging device is attached to the rotatable support device and configured to apply X-rays to the subject from plural directions while rotating around the subject to perform X-ray imaging. A target recognizing device recognizes a three-dimensional position of the target in the subject from X-ray images acquired by the X-ray imaging device; and CT image generating devices are configured to select, from the X-ray images acquired by the X-ray imaging device, the images in which the position of the target recognized by the recognizing device satisfies the treatment radiation irradiation condition for the motion tracking treatment to perform image reconstruction and generate a cone beam CT image.

Abstract: First ions and second ions that are heavier than first ions are generated in an ion source. One kind of ions of the first ions and second ions is injected into an accelerator by action of a switching magnet and accelerated in the accelerator. An ion beam including the one kind of ions is extracted from the accelerator to a beam transport system and a tumor volume of a patient is irradiated with the ion beam from an irradiation nozzle. In the irradiation of the ion beam, a tumor volume depth and the largest underwater range of each ion species are compared, and an ion species in which the tumor volume depth becomes the longest underwater range or lower is injected into the accelerator, and accelerated by the accelerator. The tumor volume is irradiated with the ion species.

Abstract: A radiotherapy system acquires an image which is necessary for positioning of a patient for radiation treatment and enables grasping of a positional relationship of a target in a treatment radiation irradiated state, a radiation passing area and a critical organ. An X-ray imaging device is attached to the rotatable support device and configured to apply X-rays to the subject from plural directions while rotating around the subject to perform X-ray imaging. A target recognizing device recognizes a three-dimensional position of the target in the subject from X-ray images acquired by the X-ray imaging device; and CT image generating devices are configured to select, from the X-ray images acquired by the X-ray imaging device, the images in which the position of the target recognized by the recognizing device satisfies the treatment radiation irradiation condition for the motion tracking treatment to perform image reconstruction and generate a cone beam CT image.

Abstract: A charged particle beam reduces treatment time in the uniform scanning or in the conformal layer stacking irradiation. In the uniform scanning, an optimum charged particle beam scan path for uniformly irradiating a collimator aperture area is calculated. In the conformal layer stacking irradiation, an optimum charged particle beam scan path for uniformly irradiating a multi-leaf collimator aperture area of each layer for each of the layers obtained by partitioning the target volume is calculated. Alternatively, a minimum irradiation field size that covers the multi-leaf collimator aperture area of each layer is calculated, and a scan path corresponding to the irradiation field size, prestored in a memory of a particle therapy control apparatus, is selected. The charged particle beam scan path is optimally changed in the lateral directions in conformity with the collimator aperture area in the uniform scanning or in each layer in the conformal layer stacking irradiation.

Abstract: Disclosed herein are provided an arrangement of devices suitable to downsize a synchrotron, a synchrotron using such an arrangement, and a particle therapy system using the synchrotron. In the synchrotron, a plurality of deflection magnets and a single defocusing quadrupole magnet are arranged between a first extraction deflector and a second extraction deflector. The defocusing quadrupole magnet is arranged between deflection magnets among the plurality of deflection magnets, a focusing quadrupole magnet is arranged on the side of an inlet of the first extraction deflector, and a focusing quadrupole magnet is arranged on the side of an outlet of the second extraction deflector.

Abstract: Disclosed herein are provided an arrangement of devices suitable to downsize a synchrotron, a synchrotron using such an arrangement, and a particle therapy system using the synchrotron. In the synchrotron, a plurality of deflection magnets and a single defocusing quadrupole magnet are arranged between a first extraction deflector and a second extraction deflector. The defocusing quadrupole magnet is arranged between deflection magnets among the plurality of deflection magnets, a focusing quadrupole magnet is arranged on the side of an inlet of the first extraction deflector, and a focusing quadrupole magnet is arranged on the side of an outlet of the second extraction deflector.

Abstract: A charged particle beam reduces treatment time in the uniform scanning or in the conformal layer stacking irradiation. In the uniform scanning, an optimum charged particle beam scan path for uniformly irradiating a collimator aperture area is calculated. In the conformal layer stacking irradiation, an optimum charged particle beam scan path for uniformly irradiating a multi-leaf collimator aperture area of each layer for each of the layers obtained by partitioning the target volume is calculated. Alternatively, a minimum irradiation field size that covers the multi-leaf collimator aperture area of each layer is calculated, and a scan path corresponding to the irradiation field size, prestored in a memory of a particle therapy control apparatus, is selected. The charged particle beam scan path is optimally changed in the lateral directions in conformity with the collimator aperture area in the uniform scanning or in each layer in the conformal layer stacking irradiation.

Abstract: A charged particle beam irradiation system includes a synchrotron which accelerates an ion beam, an irradiation apparatus for irradiating an object with the ion beam introduced from the synchrotron, detection means for measuring an amount of accumulated charge of the ion beam that orbits in the synchrotron immediately before an extraction control period in an operating cycle of the synchrotron, and beam extraction control means for controlling extraction of the ion beam based on the measurement result of the accumulated beam charge amount so that extraction of a total amount of the ion beam is to be completed with an expiration of an extraction control time, the extraction control time representing a length of the extraction control period of the synchrotron and being set in advance.

Abstract: In a charged particle irradiation system, forming a uniform dose distribution is required by irradiating a moving irradiation object through beam scanning and energy stacking. The charged particle irradiation system includes an ion beam generator 1 from which an ion beam is extracted with a target beam current value thereof set; an irradiation nozzle 21 having scanning magnets 23, 24 and an energy filter 26, the irradiation nozzle 21 for irradiating an irradiation object with the ion beam; and an irradiation object monitoring unit 66 for measuring a position of the irradiation object and outputting signals that vary with time according to displacement of the irradiation object. The charged particle irradiation system determines extraction timing of the ion beam based on the signal outputted from the irradiation object monitoring unit 66 and sequentially changes energies of the ion beam to thereby perform a repainting irradiation with each of the energies.

Abstract: A charged particle irradiation system that positions the beam at a target position to avoid irradiation of normal tissue includes an acceleration system 6 for extracting a charged particle beam, scanning magnets 24 and 25, and charged particle beam position monitors 26 and 27. On the basis of signals received from the charged particle beam position monitors 26 and 27, the control unit 70 calculates a beam position at a target position and then controls the scanning magnets 24 and 25 so that the charged particle beam is moved to a desired irradiation position at the target position. The control unit 70 corrects the value of an excitation current applied to each of the scanning magnets 24 and 25 on a specified cycle basis on the basis of information about the position and the angle of the charged particle beam.

Abstract: A charged particle beam irradiation system and a charged particle beam extraction method which can prevent erroneous irradiation of a charged particle beam in the direction of advance of the charged particle beam. The system and method are featured in stopping supply of an ion beam to one or more of a plurality of angle zones in each of which a target dose is attained, the angle zones being formed by dividing an RMW in a rotating direction thereof, and in allowing the supply of the ion beam to one or more other angle zones in each of which a target dose is not yet attained. The invention can easily adjust beam doses at various positions in an affected part of the patient body in the direction of advance of the ion beam, and can greatly reduce the probability of erroneous irradiation that the beam dose becomes excessive or deficient at the various positions within the affected part of the patient body in the direction of advance of the ion beam.

Abstract: In a charged particle irradiation system, forming a uniform dose distribution is required by irradiating a moving irradiation object through beam scanning and energy stacking. The charged particle irradiation system includes an ion beam generator 1 from which an ion beam is extracted with a target beam current value thereof set; an irradiation nozzle 21 having scanning magnets 23, 24 and an energy filter 26, the irradiation nozzle 21 for irradiating an irradiation object with the ion beam; and an irradiation object monitoring unit 66 for measuring a position of the irradiation object and outputting signals that vary with time according to displacement of the irradiation object. The charged particle irradiation system determines extraction timing of the ion beam based on the signal outputted from the irradiation object monitoring unit 66 and sequentially changes energies of the ion beam to thereby perform a repainting irradiation with each of the energies.

Abstract: A charged particle beam extraction system and method capable of shortening the irradiation time and increasing the number of patients treatable per unit time. The charged particle beam extraction system comprises a synchrotron for cyclically performing patterned operation including four steps of introducing, accelerating, extracting and decelerating an ion beam, an on/off switch for opening or closing connection between an RF knockout electrode and an RF power supply for applying RF power to the RF knockout electrode, and a timing controller for controlling on/off-timing of the on/off switch such that when extraction of the ion beam is stopped at least once during the extraction step of the synchrotron, an amount of the ion beam extracted from the synchrotron in one cycle is held substantially at a setting value.

Abstract: To ensure irradiation accuracy and safety, even when an irradiation device employing a different irradiation method is used, disclosed is herein a charged particle beam irradiation apparatus that irradiates an irradiation target with charged particle beams includes: a charged particle beam generator for generating the charged particle beams; a passive scattering irradiation device and a scanning irradiation device, both for irradiating the irradiation target with the charged particle beams; a beam transport system for transporting the charged particles beam extracted from the charged particle beam generator, to selected one of the two irradiation devices; and a central controller that modifies operating parameters on the charged particle beam generator, according to the irradiation method adopted for the selected irradiation device.