Mitsubishi Electric Corporation

Hitachi, Ltd.

Kengo Sugahara

Shuhei Odawara

Kazushi Hanakawa

Katsuhisa Yoshida

Masahiro Ikeda

Hisashi Harada

Taizo Honda

Toshihiro Otani

Kazuo Yamamoto

Satoshi Azuma

Takaaki Iwata

Hirofumi Tanaka

Nobuyuki Haruna

Tadashi Katayose

Daisuke Itoh

Masataka Yabuuchi

Yasuto Kishii

Kazuhiro Nishi

Shinichi Masuno

Fumihiko Kashima

Toshihiro Ohtani

A circular accelerator that accelerates charged particles orbiting along an orbital path to a predetermined energy to perform, by deviating the path from the orbital path to an extraction path, extraction of the charged particles exceeding a stable region formed by multipole electromagnets, includes a multipole electromagnet energization control unit setting energization of the multipole electromagnets so that part of the charged particles are deviated to a discarding path other than the extraction path to discard unwanted charged particles, and then setting energization of the multipole electromagnets so that the charged particles orbiting in the orbital path are deviated to the extraction path to perform extraction of the charged particles.

Circular accelerator, circular accelerator operation method, and particle-beam therapy device

A device controller controls an acceleration-related devices and an extraction-related devices of an accelerator for accelerating and extracting a particle beam, in such a way that the controller checks, at a time point when receiving a master clock pulse, that preparation for operating the acceleration-related devices is completed and then commands the acceleration-related devices to operate in accordance with an operation pattern corresponding to a prescribed energy of the particle beam, and commands the acceleration-related devices to operate in accordance with an extracting operation pattern when an extraction enable signal indicating that the particle beam reaches the prescribed energy is turned ON and an extraction-related device setting-status signal indicating that completion of setting the extraction-related devices for the prescribed energy is ON.

Particle beam therapy device

In a beam transport system, based on a beam temporal-variation related amount that has been calculated by a beam analyzer and that is a beam-position temporal variation amount or a beam diameter at a beam profile monitor, an optical parameter calculator calculates a start-point momentum dispersion function that is a momentum dispersion function (&#x3b7;, &#x3b7;') of a charged particle beam at a start point in design of the beam transport system that is set on a beam trajectory of the accelerator; and calculates optical parameters using, as an initial condition, the start-point momentum dispersion function and a beginning condition at an irradiation position at the time of detecting profile data.

Beam transport system and particle beam therapy system

When an energy of a particle beam to be emitted from an accelerator is set for every slice group including two or more adjacent slices and an attenuation amount is set for each slice in the slice group, the energy to be emitted from the accelerator is set, for every slice group, higher than an energy corresponding to the slice at a deepest location in that slice group so that a transmissive plate has a predetermined thickness for the slice at the deepest location; and, with respect to a thickness of the transmissive plate to be set for every slice group, the thickness set for the slice group at a deep location is larger than or equal to the thickness set for the slice group at a shallow location, and the thickness set for the slice group at a deepest location is thicker than the thickness set for the slice group at a shallowest location.

Particle beam treatment device and operation method therefor

A method of manufacturing a radio frequency accelerator that accelerates charged particles injected into a second-stage linear accelerator from a first-stage linear accelerator includes a step of setting a value of a power distribution factor R for the power distributor to supply radio frequency power to the second-stage linear accelerator and a value of a ratio L/&#x3c9; of a length L of the matching section between the outlet of the first-stage linear accelerator and the inlet of the second-stage linear accelerator to the angular frequency &#x3c9; of the radio frequency power, so that a charged particle beam is extracted from the second-stage linear accelerator over a range of the total radio frequency power wider than a widest allowable range among allowable total radio frequency power ranges determined for each phase of charged particles on the basis of phase acceptance of the second-stage accelerator.

Method of manufacturing radio frequency accelerator, radio frequency accelerator, and circular accelerator system

A particle beam treatment system includes an accelerator system that accelerates a charged particle beam and a beam transport system that transports a high-energy beam emitted from the accelerator to an irradiation location, wherein the beam transport system is provided with at least one steering electromagnet and at least one beam position monitor corresponding to the at least one steering electromagnet, and wherein the at least one beam position monitor supplies an excitation current for correcting a beam position, which periodically varies, to the at least one steering electromagnet.

Particle beam treatment system and beam position correcting method thereof

In gantry type particle beam irradiation system comprising a gantry and being configured to irradiate a particle beam, which has small emittance in X direction and large emittance in Y direction at an extraction position of a circular accelerator, from an irradiation nozzle installed in the gantry to an irradiation target, the irradiation nozzle has a ridge filter which is installed so as for a direction in which emittance in X direction is maintained to tilt to a direction which is perpendicular to a ridge of the ridge filter by a predetermined angle in the state where the gantry is a reference angle.

Gantry-type particle beam irradiation system and particle beam therapy system comprising same

A charged particle beam transport system is characterized in that in a fixed transport unit, a phase of a phase space distribution of a charged particle beam at an inlet of a rotating deflection unit that rotates around an gantry rotation axle of a rotating gantry coincides with a phase determined by a calculation based on an average value of a first phase advance and a second phase advance. The first phase advance is defined as a change in a phase, of the phase space distribution, that changes when the charged particle beam travels from the inlet of the rotating deflection unit to an isocenter in the case where a gantry angle is a gantry reference angle; the second phase advance is defined as a change in a phase at a time when the gantry angle is pivoted by 90&#xb0; from the gantry reference angle.

Charged particle beam transport system and particle beam therapy system

A septum magnet includes a yoke that can be separated at the approximately center portion thereof in the axis direction; a septum coil; a return coil; and a vacuum duct that is inserted between the septum coil and the return coil. The septum coil is formed in such a way as to be able to be separated into a first portion and a second portion in response to separation of the yoke; and in a space between the septum coil and the vacuum duct, there is provided an auxiliary coil, in two portions of which, corresponding to the first portion and the second portion of the septum coil, electric currents flow in opposite direction to each other in a circumferential direction.

Septum magnet and particle beam therapy system

A circular accelerator comprises a target current value memory which stores a target current value of a beam current of charged particle which is extracted from an extracting device; and a frequency determination part in which a frequency change ratio is obtained by performing a feedback control based on an error signal between a detection signal of a beam current detector and a target current value which is stored in a target current value memory, and determines a subsequent frequency from the obtained frequency change ratio and a current frequency, wherein the subsequent frequency which is determined by the frequency determination part is stored in a frequency memory and a radio-frequency generator generates the subsequent radio-frequency of frequency which is determined.

Circular accelerator and its operation method

The objective is to eliminate the effect of the hysteresis of a scanning electromagnet and resume high-accuracy beam irradiation from an irradiation position where it has been interrupted, even in the case where emergency-stop processing is performed during therapy. There are provided an irradiation management apparatus that controls a scanning electromagnet; and an interlock information inputting device that generates an interlock signal for stopping irradiation of the charged particle beam, when a contingency occurs. When irradiation of the charged particle beam is resumed, the irradiation management apparatus performs idle operation in which the scanning electromagnet is controlled, with the charged particle beam unirradiated, from a start step, which is situated prior to a stop step and is different from the initial step in actual irradiation, to the stop step, and then irradiates the charged particle beam from the desired irradiation position coordinates corresponding to the stop step.

Particle beam therapy system

The object is to effectively reduce the resonant current flowing inside a converter unit and an inverter unit in a power conversion apparatus for an electric vehicle. The power conversion apparatus includes a converter unit that converts an alternating-current power into a direct-current power, an inverter unit that converts the direct-current power into an intended alternating-current power and supplies the intended alternating-current power to an electric motor that drives an electric vehicle, a housing that accommodates the converter unit and the inverter unit and a part of which is connected to ground, and a magnetic core that is disposed inside the housing and that suppresses the resonant current flowing between the converter unit and the inverter unit.

Growing community of inventors

Tokyo, Japan

Kengo Sugahara