Abstract: A multi-energy frequency-multiplying particle accelerator and a method thereof are disclosed, an accelerator comprises a pulse power generation unit for generating N pulse signals with different power levels, N is equal to or greater than 2; N microwave power generation units for, under the control of a control signal, generating N microwaves with different energy levels based on said N pulse signals, respectively; a power mixing unit having N entrances and one exit and for inputting a corresponding microwave among said N microwaves from each of said N entrances and outputting said N microwaves from said one exit; a particle beam generation unit for generating N particle beams in synchronization with said N microwaves; and an accelerating unit for using said N microwaves to accelerate said N particle beams, respectively.

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 method of irradiating a target in a subject using charged particle therapy includes the steps of positioning a subject on a supporting device, positioning a delivery device adapted to deliver charged particles, and delivering charged particles to a target in the subject wherein the delivery device rotates around the target during delivery of at least a portion of the charged particles.

Abstract: A multi-energy frequency-multiplying particle accelerator and a method thereof are disclosed in order to overcome the drawbacks of the existing accelerator, such as single energy level, beam current and operating frequency limited by a single power source. The accelerator comprises a pulse power generation unit for generating N pulse signals with different power levels, N is equal to or greater than 2; N microwave power generation units for, under the control of a control signal, generating N microwaves with different energy levels based on said N pulse signals, respectively; a power mixing unit having N entrances and one exit and for inputting a corresponding microwave among said N microwaves from each of said N entrances and outputting said N microwaves from said one exit; a particle beam generation unit for generating N particle beams in synchronization with said N is microwaves; and an accelerating unit for using said N microwaves to accelerate said N particle beams, respectively.

Abstract: The invention comprises a charged particle beam acceleration, extraction, and/or targeting method and apparatus used in conjunction with charged particle beam radiation therapy of cancerous tumors. Novel design features of a synchrotron are described. Particularly, turning magnets, edge focusing magnets, concentrating magnetic field magnets, winding and control coils, and extraction elements are described that minimize the overall size of the synchrotron, provide a tightly controlled proton beam, directly reduce the size of required magnetic fields, directly reduces required operating power, and allow continual acceleration of protons in a synchrotron even during a process of extracting protons from the synchrotron.

Abstract: A particle beam therapy system using a spot scanning method includes a synchrotron, a beam transport system, an irradiation system, and a controller. A controller is configured to turn on a radio frequency electromagnetic field to be applied to an extraction system when a charged particle beam is to be supplied to the irradiation system, and turn off the radio frequency electromagnetic field to be applied to the extraction system when the supply of the charged particle beam to the irradiation system is to be blocked by means of an electromagnet provided in the beam transport system or in the synchrotron. The controller is also adapted to turn off a radio frequency acceleration voltage to be applied to an acceleration cavity in synchronization with the turning-off of the radio frequency electromagnetic field to be applied to the extraction device.

Abstract: [PROBLEMS] To provide an induction voltage control device (8) capable of accelerating arbitrary charged particles to an arbitrary energy level in synchronization with any magnetic excitation pattern even for an acceleration voltage (9a) of constant voltage by an induction acceleration cell (6) for acceleration and its control method. [MEANS FOR SOLVING PROBLEMS] An induction voltage control device (8) includes: a digital signal processing device (8d) for controlling a variable delay time according to a necessary variable delay time pattern obtained based on a magnetic excitation pattern, an equivalent acceleration voltage value pattern, and a passing signal (7a) of a bunch (3) from a bunch monitor (7); and a pattern generator (8b) for conversion to a gate signal pattern (8a) of a switching power source (5b). The induction voltage control device (8) controls a pulse density of the induction voltage (9) for acceleration per control unit.

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.

Abstract: The invention relates to treatment of solid cancers and more particularly to a method and apparatus correlating proton beam intensity with proton delivery efficiency, optionally in a raster beam scanning system. The system induces betatron oscillation on the proton beam causing the beam to traverse an extraction material resulting in slowed protons and a feedback current proportional to the proton flux. A controller receives the desired intensity from an irradiation plan and the feedback current and adjusts the radio-frequency field in the radio-frequency cavity system to yield an intensity of the proton beam that matches the desired intensity from the irradiation plan. Preferably, the intensity of the proton beam correlates with radiation delivery efficiency. The system preferably operates in conjunction with a multi-field charged particle cancer therapy system, with charged particle beam injection, particle beam acceleration, multi-axis charged particle beam control, and/or targeting methods and apparatus.

Abstract: The invention relates to method and apparatus for treatment of solid cancer. More particularly, the invention comprises a multi-axis and/or multi-field charged particle cancer therapy system. The system independently controls patient translation position, patient rotation position, two-dimensional beam trajectory, delivered beam energy, delivered beam intensity, timing of charged particle delivery, and/or distribution of radiation striking healthy tissue. The system operates in conjunction with a negative ion beam source, synchrotron, patient positioning, imaging, and/or targeting method and apparatus to deliver an effective and uniform dose of radiation to a tumor while distributing radiation striking healthy tissue.

Abstract: The invention relates generally to treatment of solid cancers. More particularly, the invention relates to enhancing synchrotron acceleration cycle usage efficiency by adjusting the synchrotron's acceleration cycle to correlate with a patient's respiration rate where efficiency refers to the duty cycle or the percentage of acceleration cycles used to deliver charged particles to the tumor. The system senses patient respiration and controls timing of negative ion beam formation, injection of charged particles into a synchrotron, acceleration of the charged particles, and extraction to yield delivery of the particles to the tumor at a predetermine period of the patient's respiration cycle. Independent control of charged particle energy and intensity is maintained during the timed irradiation therapy. Multi-field irradiation ensures efficient delivery of Bragg peak energy to the tumor while spreading ingress energy about the tumor.

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.

Abstract: This invention relates generally to treatment of solid cancers. More particularly, the invention relates to a computer controlled patient positioning, immobilization, and repositioning method and apparatus used in conjunction with multi-field charged particle cancer therapy coordinated with patient respiration patterns and further in combination with charged particle beam injection, acceleration, extraction, and/or targeting methods and apparatus.

Abstract: The magnetic field in an acceleration chamber defined by a magnet structure is shaped by shaping the poles of a magnetic yoke and/or by providing additional magnetic coils to produce a magnetic field in the median acceleration plane that decreases with increasing radial distance from a central axis. The magnet structure is thereby rendered suitable for the acceleration of charged particles in a synchrocyclotron. The magnetic field in the median acceleration plane is “coil-dominated,” meaning that a strong majority of the magnetic field in the median acceleration plane is directly generated by a pair of primary magnetic coils (e.g., superconducting coils) positioned about the acceleration chamber, and the magnet structure is structured to provide both weak focusing and phase stability in the acceleration chamber. The magnet structure can be very compact and can produce particularly high magnetic fields.

Abstract: A fast electromagnet device (140) receives a high voltage from a pulse power supply through a coaxial cable and excites an electromagnet at high speed, so as to bend a charged particle beam. The fast electromagnet device (140) includes a kicker magnet (150) and an auxiliary circuit (160). The kicker magnet (150) is equivalent to a circuit element of a lumped constant circuit, is formed with a space penetrating in the traveling direction of the charged particle beams, instantaneously generates a magnetic field in the penetrated space with a high voltage applied, and bends the charged particle beams passing through the penetrated space. The auxiliary circuit (160) constitutes a matching circuit in combination with the kicker magnet (150), so that the input impedance of the matching circuit and the characteristic impedance of the coaxial cable connected to the input terminal of the matching circuit are matched.

Abstract: The invention comprises a charged particle beam acceleration, extraction, and/or targeting method and apparatus used in conjunction with charged particle beam radiation therapy of cancerous tumors. Novel design features of a synchrotron are described. Particularly, turning magnets, edge focusing magnets, concentrating magnetic field magnets, winding and control coils, flat surface incident magnetic field surfaces, and extraction elements are described that minimize the overall size of the synchrotron, provide a tightly controlled proton beam, directly reduce the size of required magnetic fields, directly reduces required operating power, and allow continual acceleration of protons in a synchrotron even during a process of extracting protons from the synchrotron.

Abstract: In a particle beam irradiation method and a particle beam irradiation apparatus in which depth direction irradiation field spread and lateral direction irradiation field spread are performed, an irradiation dose in each of the irradiation layers of an irradiation target is made substantially constant, the control is simplified, and the irradiation error by the displacement of the irradiation target is reduced. The depth direction irradiation field spread is an active irradiation field spread to superimpose plural irradiation layers having different ranges in the irradiation direction of the particle beam. A bolus having a shape along a deepest part of the irradiation target in the depth direction is disposed to cross the particle beam. At least one irradiation layer selected from the plural irradiation layers is re-irradiated one or more times with the particle beam.

Abstract: The invention is intended to increase the number of patients treatable using one wheel having a thickness varied in the rotating direction to change energy of an ion beam passing the wheel. Ion beam delivery equipment for irradiating an ion beam to a patient for treatment comprises a beam generator for producing and accelerating the ion beam, an beam delivery nozzle including a range modulation wheel which has a predetermined thickness distribution in the rotating direction and is rotated on a travel passage of the ion beam generated from the beam generator to control a range of the ion beam, and an irradiation controller for controlling the beam producing and accelerating operation of the beam generator in accordance with the phase of rotation of the range modulation wheel.

Abstract: It is an object of the present invention to provide an accelerator that can accelerate by itself all ions up to any energy level allowed by the magnetic fields for beam guiding, and provides an all-ion accelerator in which with trigger timing and a charging time of an induced voltage applied to an ion beam injected from a preinjector by induction cells for confinement and acceleration used in an induction synchrotron, digital signal processors for confinement and acceleration and pattern generators for confinement and acceleration generate gate signal patterns for confinement and acceleration on the basis of a passage signal of the ion beam and an induced voltage signal for indicating the value of the induced voltage applied to the ion beam, and intelligent control devices for confinement and acceleration perform feedback control of on/off of the induction cells for confinement and acceleration.

Abstract: A particle beam irradiation apparatus includes a synchrotron, two scanning electromagnets, a beam delivery apparatus for outputting an ion beam extracted from the synchrotron, and an accelerator and transport system controller, and a scanning controller. These controllers stop the output of the ion beam from the beam delivery apparatus; in a state where the output of the ion beam is stopped, change the irradiation position of the ion beam by controlling the scanning electromagnets; and after this change, control the scanning electromagnets to start the output of the ion beam from the beam delivery apparatus and to perform irradiations of the ion beam to at least one irradiation position a plurality of times based on treatment planning information.

Abstract: Apparatus and method for trapping uncharged multi-pole particles comprises a bound cavity for receiving the particles, and a multiplicity of electrodes coupled to the cavity for producing an electric field in the cavity. In a preferred embodiment, the electrodes are configured to produce in the electric field potential both a multi-pole (e.g., dipole) component that aligns the particles predominantly along an axis of the cavity and a higher order multi-pole (e.g., hexapole) component that forms a trapping region along the axis. In one embodiment, the electrodes and/or the particles are cooled to a cryogenic temperature.

Abstract: The present invention provides a multi-beam klystron apparatus. In the above-described multi-beam klystron apparatus, the magnetic field generating element of the electron-gun-unit-side magnetic field generating unit is disposed around the electron gun unit, and a plurality of magnetic gaps are provided in the inner peripheral surface of the magnetic pole, which covers the magnetic field generating element, in the direction of travel of the electron beams. Therefore, lines of magnetic force, which are parallel to the center axis of the radio-frequency interaction unit, can be generated. Thus, even the electron beam, which is generated from the location apart from the center axis of the electron gun unit, can be guided to the radio-frequency interaction unit in the same manner as in the location at the canter axis of the electron gun unit.

Abstract: A medical synchrotron which cycles rapidly in order to accelerate particles for delivery in a beam therapy system. The synchrotron generally includes a radiofrequency (RF) cavity for accelerating the particles as a beam and a plurality of combined function magnets arranged in a ring. Each of the combined function magnets performs two functions. The first function of the combined function magnet is to bend the particle beam along an orbital path around the ring. The second function of the combined function magnet is to focus or defocus the particle beam as it travels around the path. The radiofrequency (RF) cavity is a ferrite loaded cavity adapted for high speed frequency swings for rapid cycling acceleration of the particles.

Abstract: A particle beam irradiation apparatus includes a synchrotron, two scanning electromagnets, an beam delivery apparatus for outputting an ion beam extracted from the synchrotron, and an accelerator and transport system controller, and a scanning controller. These controllers stop the output of the ion beam from the beam delivery apparatus; in a state where the output of the ion beam is stopped, change the irradiation position of the ion beam by controlling the scanning electromagnets; and after this change, control the scanning electromagnets to start the output of the ion beam from the beam delivery apparatus and to perform irradiations of the ion beam to at least one irradiation position a plurality of times based on treatment planning information.

Abstract: A particle beam therapy system comprises a charged particle beam generator for generating a charged particle beam, two or more treatment rooms provided with respective irradiation devices for irradiating the charged particle beam, a beam line for transporting the charged particle beam extracted from the charged particle beam generator to the irradiation device in selected one of the two or more treatment rooms, a beam detection processing/control unit for monitoring a beam state of the charged particle beam in one of the two or more irradiation devices, and a selector for switchably selecting one of the irradiation devices which is to be monitored by the beam detection processing/control unit. The selector is controlled such that the selector establishes connection with the irradiation device in the selected one treatment room to which the charged particle beam is transported through the beam line. The system configuration can be simplified while maintaining the operation efficiency.

Abstract: An electrostatic fluid acceleration and method of operation thereof includes at least two synchronously powered stages. A single power supply or synchronized and phase controlled power supplies provide high voltage power to each of the stages such that both the phase and amplitude of the electric power applied to the corresponding electrodes are aligned in time. The frequency and phase control allows neighboring stages to be closely spaced at a distance of from 1 to 2 times an inter-electrode distance within a stage, and, in any case, minimizing or avoiding production of a back corona current from a corona discharge electrode of one stage to an electrode of a neighboring stage. Corona discharge electrodes of neighboring stages may be horizontally aligned, complementary collector electrodes of all stages being similarly horizontally aligned between and horizontally offset from the corona discharge electrodes.

Abstract: In one embodiment of the present invention, thermal deformation or bending of membranes in a transition radiation emitting structure can be reduced by providing flex regions in the membranes or the membrane support structures. In a second embodiment, deformation of membranes is compensated for by fabricating the membranes to cooperatively bend in a similar manner and direction. In a third embodiment, deformation of the membrane is reduced by fabricating the membranes with an intrinsic tensile or compressive stress.

Abstract: A particle beam irradiation system which can increase an availability factor. An ion beam extracted from one proton beam linac is bent at 90 degrees by a switching magnet and is introduced to RI production equipment through a beam line. In the RI production equipment, a RI is produced using the introduced ion beam. An ion beam extracted from the other proton beam linac is bent at 90 degrees by the switching magnet and is introduced to a synchrotron through a beam line. The ion beam extracted from the synchrotron is irradiated to a patient from irradiation equipment. If one proton beam linac comes into an abnormal state, the one proton beam linac is stopped in operation and checked. During the check, the ion beam extracted from the other proton beam linac is selectively introduced to the RI production equipment and the synchrotron by the switching magnet.

Abstract: In an undulator for the generation of synchrotron radiation from a particle beam introduced into the undulator, two partial undulators are provided each comprising a conductor of superconductive material which, when a current is conducted therethrough, generates an undulator field that extends perpendicularly to the current flow, and the superconductive conductors are arranged in the individual partial undulators such that the undulator fields generated are not parallel, whereby, by controlling the energization of the two partial undulators, the polarization direction of the synchrotron radiation can be adjusted without mechanical movements.

Abstract: An electron tube for communication is provided with an output waveguide that is directly coupled to an outlet port of a RF (Radio Frequency) wave signal, and at least one of a low-pass filter, a high-pass filter, and a band-pass filter is included inside the output waveguide.

Abstract: A particle therapy system is provided which can simply and quickly correct a beam orbit. In a particle therapy system provided with an irradiation facility comprising a first beam transport system for receiving a beam and transporting the beam to the patient side, and an irradiation nozzle for forming an irradiation field of the beam, the particle therapy system comprises first beam position monitors for detecting a position upstream of the irradiation nozzle at which the beam passes, second beam position monitors for detecting a position downstream of the irradiation nozzle at which the charged-particle beam passes, and first and second steering magnets. Correction bending amounts for causing the beam to be coincident with a predetermined orbit after the correction are determined in accordance with detected results from the first and second beam position monitors, and first and second steering magnets are excited under control so that the determined correction bending amounts are obtained.

Abstract: An electrostatic fluid acceleration and method of operation thereof includes at least two synchronously powered stages with final or rear-most electrodes of one stage maintained at substantially the same instantaneous voltage as the immediately adjacent initial or forward-most electrodes of a next stage in an airflow direction. A single power supply or synchronized and phase controlled power supplies provide high voltage power to each of the stages such that both the phase and amplitude of the electric power applied to the corresponding electrodes are aligned in time. The frequency and phase control allows neighboring stages to be closely spaced at a distance of from 1 to 2 times an inter-electrode distance within a stage, and, in any case, minimizing or avoiding production of a back corona current from a corona discharge electrode of one stage to an electrode of a neighboring stage.

Abstract: A particle therapy system is provided which can simply and quickly correct a beam orbit. In a particle therapy system provided with an irradiation facility comprising a first beam transport system for receiving a beam and transporting the beam to the patient side, and an irradiation nozzle for forming an irradiation field of the beam, the particle therapy system comprises first beam position monitors for detecting a position upstream of the irradiation nozzle at which the beam passes, second beam position monitors for detecting a position downstream of the irradiation nozzle at which the charged-particle beam passes, and first and second steering magnets. Correction bending amounts for causing the beam to be coincident with a predetermined orbit after the correction are determined in accordance with detected results from the first and second beam position monitors, and first and second steering magnets are excited under control so that the determined correction bending amounts are obtained.

Abstract: A method of producing synchrotron radiation comprising the steps of accelerating and compressing an electron beam generated from an electron source by means of a pre-accelerator, further accelerating the electron beam in a main accelerator to produce synchrotron radiation on a recirculation orbit, decelerating the electron beam in the main accelerator to recover its energy and discarding it into a beam dump, said pre-accelerator being an energy-recovery pre-accelerator and posited before the main accelerator on said recirculation orbit so that it also performs energy recovery through beam deceleration, thereby reducing the rf power it is supplied with externally for beam acceleration.

Abstract: A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

Abstract: The invention relates to a compact time-of-flight mass spectrometer which enables very accurate mass determinations. The invention consists of a method of producing a high resolution by means of a long flight path, where the ion beam repeatedly sweeps a figure of eight in two opposed cylindrical capacitors, each of 254.56°, and the linear ion beam paths between the cylindrical capacitors are extended virtually by a change in potential so as to cause a time focusing with respect to an initial energy spread.

Abstract: A method for using a synchrotron, the method including the steps of: providing a synchrotron designed to accelerate a hadron beam to higher momenta; altering said synchrotron to enable deceleration of hadron beams to lower momenta; and using the synchrotron in said altering step in decelerating a hadron beam to lower momentum.

Abstract: A method of producing synchrotron radiation comprising the steps of accelerating and compressing an electron beam generated from an electron source by means of a pre-accelerator, further accelerating the electron beam in a main accelerator to produce synchrotron radiation on a recirculation orbit, decelerating the electron beam in the main accelerator to recover its energy and discarding it into a beam dump, said pre-accelerator being an energy-recovery pre-accelerator and posited before the main accelerator on said recirculation orbit so that it also performs energy recovery through beam deceleration, thereby reducing the rf power it is supplied with externally for beam acceleration.

Abstract: To provide an accelerator system having a wide ion beam current control range, being capable of operating with low power consumption and a long maintenance interval and being capable of preventing unnecessarily large dose of the ion beam for irradiation from erroneously being supplied to the downstream side of the system. In an accelerator system designed to treat the patient with irradiation of a high-energy ion beam accelerated by a post-accelerator 4 comprising a synchrotron in irradiation rooms 6 to 8, a value of ion beam current to be supplied to the post-accelerator 4 is controlled by a pre-accelerator comprising an ion source 10, quadrupole electromagnet 15, radio frequency quadrupole accelerator 17 and a drift tube type accelerator 19. The accelerator system featuring low power consumption, a long maintenance interval and high reliability can be made available.

Abstract: Systems and techniques to generate extreme ultraviolet (EUV) illumination. An EUV system includes first layers, and second layers interleaved with the first layers, where the first layers and the second layers have a thickness selected to produce coherent transition radiation in an extreme ultraviolet wavelength region when an electron beam passes through the first layers and the second layers. The first and second layers may be built using thin film deposition techniques and etching techniques. The first layers may include metal, such as molybdenum. The second layers may include a dielectric material and may define regions of vacuum between the first layers, including possibly multiple regions of vacuum per layer.

Abstract: A particle therapy system is provided which can simply and quickly correct a beam orbit. In a particle therapy system provided with an irradiation facility comprising a first beam transport system for receiving a beam and transporting the beam to the patient side, and an irradiation nozzle for forming an irradiation field of the beam, the particle therapy system comprises first beam position monitors for detecting a position upstream of the irradiation nozzle at which the beam passes, second beam position monitors for detecting a position downstream of the irradiation nozzle at which the charged-particle beam passes, and first and second steering magnets. Correction bending amounts for causing the beam to be coincident with a predetermined orbit after the correction are determined in accordance with detected results from the first and second beam position monitors, and first and second steering magnets are excited under control so that the determined correction bending amounts are obtained.

Abstract: A method for using a synchrotron, the method including the steps of: providing a synchrotron designed to accelerate a hadron beam to higher momenta; altering said synchrotron to enable deceleration of hadron beams to lower momenta; and using the synchrotron in said altering step in decelerating a hadron beam to lower momentum.

Abstract: An accelerator system which can be implemented in a small size at low manufacturing cost and which can nonetheless ensure a high utilization efficiency of the ion beam. The system includes an ion source for generating an ion beam, pre-accelerators for accelerating the ion beam generated by the ion source, an radioisotope producing unit for irradiating a target with the ion beam accelerated by the pre-accelerators for producing radioisotopes, a synchrotron into which the ion beam accelerated by the pre-accelerators is injected and from which the ion beam is ejected after acceleration, and a selector electromagnet for introducing the ion beam accelerated by the pre-accelerators into either the radioisotope producing unit or the synchrotron.

Abstract: A control method and apparatus of a circular accelerator can adjust a timing of emitting a charged particle beam in the circular accelerator. Generation of a clock pulse having a fixed period is suspended after acceleration of the charged particle beam has been ended and the generation of the clock pulse is resumed when a beam irradiation request is produced on the basis of a state of an object to be irradiated during the suspension state of generation of the clock pulse. An emitter is operated in accordance with the clock pulse generated again.

Abstract: A device for varying the energy of a particle beam extracted from a fixed-energy particle accelerator includes a block of energy degrading material positioned in the path of the particle beam. The block of energy degrading material is preferably in the form of a ring arranged on a wheel. The ring is of a staircase configuration, having discrete steps defining a thickness between parallel entry and exit faces. According to one aspect of the invention, the block is configured so that the particle beam energy variation reaches a maximum at the edges of each step. This upper limit is also the lower limit of the next step. Thus, continuous energy variation is possible despite the fact that the thickness of the block varies in discrete steps.

Abstract: A charged-particle beam irradiation system for an affected part in which while a charged-particle beam ejected from an accelerator is scanned by an electromagnet onto the affected part, each layer of the affected part resulting from division of the affected part into a plurality of layers in a direction of progression of said charged-particle beam is irradiated with the charged-particle beam. The system includes a changer for changing an energy of said charged-particle beam in accordance with a layer of the plurality of layers to be irradiated with the charged-particle beam and an intensity controller for controlling an intensity of the charged-particle beam.

Abstract: An electromagnet comprises a pair of magnetic pole 1a and 1b, a return yoke 3, exciting coils 4 and 5, etc. In an interior portion of a magnetic pole, plural spacers 2a-2g are provided putting side by side in a horizontal direction. Each of the spaces 2a-2g is an air layer and a longitudinal cross-section is a substantially rectangular shape and the space has a lengthily extending slit shape in a vertical direction against a paper face in FIG. 1. The plural spaces are mainly arranged toward a right side from a beam orbit center O and an interval formed between adjacent spaces is narrower toward the right side. The electromagnet having a simple magnetic pole structure and a wide effective magnetic field area in a case where a maximum magnetic field strength is increased can be secured.

Abstract: A charged-particle beam irradiation method and system are disclosed in which while a charged-particle beam ejected from an accelerator is scanned by an electromagnet, each layer resulting from the division of an affected part into a plurality of layers in the direction of progression of the charged-particle beam is irradiated with the charged-particle beam. The intensity of a charged-particle beam for irradiation of a first layer is made lower than the intensity of a charged-particle beam for irradiation of a second layer existing at a position deeper than the first layer in the beam progressing direction. A scanning speed in the first layer is changed between a portion of the first layer subjected to irradiation at the time of irradiation of the second layer and a portion of the first layer subjected to no irradiation at the time of irradiation of the second layer.

Abstract: A charged-particle beam irradiation method and system are disclosed in which while a charged-particle beam ejected from an accelerator is scanned by an electromagnet, each layer resulting from the division of an affected part into a plurality of layers in the direction of progression of the charged-particle beam is irradiated with the charged-particle beam. The intensity of a charged-particle beam for irradiation of a first layer is made lower than the intensity of a charged-particle beam for irradiation of a second layer existing at a position deeper than the first layer in the beam progressing direction. A scanning speed in the first layer is changed between a portion of the first layer subjected to irradiation at the time of irradiation of the second layer and a portion of the first layer subjected to no irradiation at the time of irradiation of the second layer.