129 results about "Linear particle accelerator" patented technology

The present invention provides a charged particle accelerator comprising a charged particle generating apparatus, a bending magnet, accelerating means and a vacuum duct, wherein first and second acceleration periods (22), (23) are provided, accelerating electric field of the accelerating means is applied from the start time (25) of the first acceleration period (22) until the end time of the second acceleration period (23), and bending magnetic field is applied at a fixed value during the first accelerating period while, during the second acceleration period, it is applied so as to increase until the end time of the second acceleration period. Accordingly, there is provided a compact and high power charged particle accelerator which can perform large-current acceleration.

A radiation therapy system comprises a magnetic resonance imaging (MRI) system combined with an irradiation system, which can include one or more linear accelerators (linacs) that can emit respective radiation beams suitable for radiation therapy. The MRI system includes a split magnet system, comprising first and second main magnets separated by gap. A gantry is positioned in the gap between the main MRI magnets and supports the linac(s) of the irradiation system. The gantry is rotatable independently of the MRI system and can angularly reposition the linac(s). Shielding can also be provided in the form of magnetic and / or RF shielding. Magnetic shielding can be provided for shielding the linac(s) from the magnetic field generated by the MRI magnets. RF shielding can be provided for shielding the MRI system from RF radiation from the linac.

The present invention provides a radiotherapy treatment apparatus that includes a treatment beam, a magnetic field disposed parallel collinear to the treatment beam, and a target that is disposed along the treatment beam. The treatment beam can be a charged particle beam, a proton beam, an electron beam, or a linear accelerator (Linac) beam. The magnetic field is from a magnetic resonance imager (MRI), a megavolt x-ray imager, or a kilovolt x-ray imager and is disposed to operate in coordination with operation of the treatment beam and to narrow the beam. The tumor is disposed to rotate with respect to the treatment beam and the magnetic field, or the treatment beam and the magnetic field are disposed to rotate up to 360° with respect to the target when mounted to a ring gantry. The apparatus can include a rotation angle dependent shim disposed to account for Earth's magnetic field.

A radiation therapy system comprises a magnetic resonance imaging (MRI) system combined with an irradiation system, which can include one or more linear accelerators (linacs) that can emit respective radiation beams suitable for radiation therapy. The MRI system includes a split magnet system, comprising first and second main magnets separated by gap. A gantry is positioned in the gap between the main MRI magnets and supports the linac(s) of the irradiation system. The gantry is rotatable independently of the MRI system and can angularly reposition the linac(s). Shielding can also be provided in the form of magnetic and / or RF shielding. Magnetic shielding can be provided for shielding the linac(s) from the magnetic field generated by the MRI magnets. RF shielding can be provided for shielding the MRI system from RF radiation from the linac.

A radiation therapy System comprises a magnetic resonance imaging (MRI) apparatus and a linear accelerator capable of generating a beam of radiation. The linear accelerator is immersed in and oriented with respect to the MRI magnetic field to expose the linear accelerator to magnetic force that directs particles therein along a central axis thereof.

The present invention provides a method for controlling nonlinear control problems within particle accelerators. This method involves first utilizing software tools to identify variable inputs and controlled variables associated with the particle accelerator, wherein at least one variable input parameter is a controlled variable. This software tool is further operable to determine relationships between the variable inputs and controlled variables. A control system that provides variable inputs to and acts on controller outputs from the software tools tunes one or more manipulated variables to achieve a desired controlled variable, which in the case of a particle accelerator may be realized as a more efficient collision.

A radiation therapy System comprises a magnetic resonance imaging (MRI) apparatus and a linear accelerator capable of generating a beam of radiation. The linear accelerator is immersed in and oriented with respect to the MRI magnetic field to expose the linear accelerator to magnetic force that directs particles therein along a central axis thereof.

According to the present invention, a non-isochronous magnetic field distribution in which the magnetic field increases as the radius increases is formed and a distribution of fixed-frequency accelerating RF voltage is formed, said non-isochronous magnetic field distribution and said distribution of fixed-frequency accelerating RF voltage being formed so that a harmonic number defined as a ratio of the particle revolution period to the period of the accelerating RF voltage decreases in integer for every particle revolution.

Some embodiments include operation of an accelerator waveguide to accelerate particles to a first energy within the waveguide, wherein a prebuncher coupled to the waveguide outputs particle bunches having a first phase, change of a phase at which particle bunches will be output from the prebuncher from the first phase to a second phase, and operation of the accelerator waveguide to accelerate particles to a second energy within the waveguide, wherein the prebuncher outputs particle bunches having the second phase. Further aspects provide change of a resonant frequency of the prebuncher from a first frequency to a second frequency. According to still further aspects, the prebuncher includes a prebuncher cavity and change of the resonant frequency comprises change of a shape of the prebuncher cavity.

This device allows the variation of the coupling between two points in an RF circuit in a very simple way while maintaining the RF phase relationship and varying the relative magnitude of the RF fields. The device is characterized by a simple mechanical control of coupling value, that has negligible effect on the phase shift across the device. This is achieved by the simple rotation of the polarisation of a TE111 mode inside a cylindrical cavity. Such a device does not contain resistive elements, and the sliding mechanical surfaces are free from high RF currents. This device finds an application in standing wave linear accelerators, where it is desirable to vary the relative RF field in one set of cavities with respect to another, in order that the accelerator can operate successfully over a wide range of energies.

A slot resonance coupled, linear standing wave particle accelerator. The accelerator includes a series of resonant accelerator cavities positioned along a beam line, which are connected by resonant azimuthal slots formed in interior walls separating adjacent cavities. At least some of the slots are resonant at a frequency comparable to the resonant frequency of the cavities. The resonant slots are offset from the axis of the accelerator and have a major dimension extending in a direction transverse to the radial direction with respect to the accelerator axis. The off-axis resonant slots function to magnetically couple adjacent cavities of the accelerator while also advancing the phase difference between the standing wave in adjacent cavities by 180 degrees in addition to the 180 degree phase difference resulting from coupling of the standing wave in each cavity with the adjacent slot, such that the signals in each cavity are in phase with one another and each cavity functions as a live accelerating cavity. The resonance frequency of the slot is the comparable to the resonance frequency of the cavities, resulting in coupling of the cavities while also eliminating the need for side-cavity or other off-axis coupling cavities.

A particle accelerator system for producing a charged particle beam having pulses of charged particles that have different energy levels from pulse to pulse. The system enables independent adjustment of the RF power delivered to first and second accelerating sections thereof without adjustment of the RF power generated by an RF source. Such independent adjustment enables the RF power provided to the first accelerating section to be maintained at a level appropriate for optimal particle capturing therein and for producing a tightly bunched beam of particles having different energy levels from pulse to pulse, while enabling the RF power provided to the second accelerating section to be varied in order to vary the energy levels of the charged particles of the charged particle beam from pulse to pulse.

A system according to some embodiments may include a treatment head to emit a megavoltage radiation beam toward a volume, a plurality of X-ray sources to emit a respective kilovoltage radiation beam toward the volume while the plurality of X-ray sources are substantially stationary with respect to the volume, a detector to receive the plurality of kilovoltage radiation beams after having passed through the volume, and a processor to generate a three-dimensional image of the volume based only on the plurality of kilovoltage radiation beams received by the detector while the plurality of X-ray sources were substantially stationary with respect to the volume.

A particle accelerator including an electrical field system and a magnetic field system that are configured to direct charged particles along a desired path within an acceleration chamber. The particle accelerator also includes a mechanical device that is located within the acceleration chamber. The mechanical device is configured to be selectively moved to different positions within the acceleration chamber. The particle accelerator also includes an electromechanical (EM) motor having a connector component and piezoelectric elements that are operatively coupled to the connector component. The connector component is operatively attached to the mechanical device. The EM motor drives the connector component when the piezoelectric elements are activated thereby moving the mechanical device.

In a charged particle accelerator, voltage of several tens of kV is applied between accelerating electrodes. In such a case, electric discharge is sometimes generated between the accelerating electrodes. In the charged particle accelerator, part or entirety of the accelerating electrodes is coated with an electric discharge suppressing layer made of ceramics or alloy having a high melting point as compared with metal. When impurity fine particles are accelerated by an electric field and collide with the electrodes, the electric discharge suppressing layer made of ceramics or alloy prevents metal vapor from being easily generated from the electrodes and an ionized plasma from being easily produced, thus suppressing electric discharge between the electrodes.

The invention relates to a power source low-level all-digital amplitude phase control system for a high-energy particle accelerator and an implementation method thereof. The method comprises cooperation of signal preprocessing, digital signal processing and digital loop control. An analog circuit component of the signal preprocessing comprises six signal processing channels and one clock processing channel integrated on an analog part, wherein each signal processing channel comprises an attenuator, an amplifier and a filter; and the clock processing channel comprises an attenuator, an amplifier, a filter, a frequency multiplier and a frequency divider. A digital circuit component of the digital signal processing and the digital loop control comprises three A / D (Analog to Digital) converters for sampling six paths of signals, one D / A (Digital to Analog) converter for generating signals and one FPGA (Field Programmable Gate Array) for the digital signal processing and the digital loop control, wherein the three A / D converters, the D / A converter and the FPGA are integrated on a digital part. Through adoption of the power source low-level all-digital amplitude phase control system, the physical structural parameters of a super conduction cavity can be controlled, and high stability of the amplitude and phase of a super conduction cavity driving energy field can be kept.

A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (˜70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

A microwave system for driving a linear accelerator is provided. The inventive microwave system employs a plurality of magnetrons, at least one pulse generator to energize the magnetrons, means for synchronizing outputs from the magnetrons, and at least one waveguide for transmitting synchronized outputs or power from the magnetrons to a linear accelerator. The linear accelerator that is driven by the inventive microwave system demonstrates increased efficiency and dependability, higher energy and power outputs, as well as, different energy outputs that can take the form of successive pulses that alternate between at least two different energy levels.

The invention aims to disclose an ambient neutron dose equivalent meter. The ambient neutron dose equivalent meter is characterized by comprising a neutron probe, a neutron energy response adjustor and a control system, wherein a neutron detection element is arranged in the neutron probe, the neutron detection element is europium-doped lithium iodide scintillation crystal, the signal output end of the neutron probe is connected with the signal input end of the control system, and the neutron probe is placed at the position of the geometric center of the neutron energy response adjustor. Because the photomultiplier with high sensitivity is used as a photoelectric converter, the meter has light weight, portability, sensitive neutron response and good angle response, can accurately measure the ambient neutron dose equivalent level, has sound and light alarm function, is used for ambient neutron radiation monitoring of large nuclear facilities such as reactors, high-energy particle accelerators and the like, ensures neutron radiation safety of the ambient and the public, and fulfills the purpose of the invention.

The objective is to obtain a charged particle accelerator where the amount of pattern data for operating an acceleration cavity and electromagnets based on time clocks is reduced and the pattern data communication time is shortened. An accelerator control apparatus provided in a charged particle accelerator of the present invention is characterized by including a clock generation unit that generates an acceleration cavity clock and an electromagnet clock that is synchronized with the acceleration cavity clock and has a frequency lower than that of the acceleration cavity clock; a high-frequency control unit that controls an acceleration cavity, based on an acceleration cavity pattern stored in a first pattern memory and the acceleration cavity clock; and a deflection electromagnet control unit that controls a deflection electromagnet, based on a deflection electromagnet pattern stored in a second pattern memory and the electromagnet clock.

A hybrid linear accelerator is disclosed comprising a standing wave linear accelerator section (“SW section”) followed by a travelling wave linear accelerator section (“TW section”). In one example, RF power is provided to the TW section and power not used by the TW section is provided to the SW section via a waveguide. An RF switch, an RF phase adjuster, and / or an RF power adjuster is provided along the waveguide to change the energy and / or phase of the RF power provided to the SW section. In another example, RF power is provided to both the SW section and the TW section, and RF power not used by the TW section is provided to the SW section, via an RF switch, an RF phase adjuster, and / or an RF power. In another example, an RF load is matched to the output of the TW section by an RF switch.

A slot resonance coupled, linear standing wave particle accelerator. The accelerator includes a series of resonant accelerator cavities positioned along a beam line, which are connected by resonant azimuthal slots formed in interior walls separating adjacent cavities. At least some of the slots are resonant at a frequency comparable to the resonant frequency of the cavities. The resonant slots are offset from the axis of the accelerator and have a major dimension extending in a direction transverse to the radial direction with respect to the accelerator axis. The off-axis resonant slots function to magnetically couple adjacent cavities of the accelerator while also advancing the phase difference between the standing wave in adjacent cavities by 180 degrees in addition to the 180 degree phase difference resulting from coupling of the standing wave in each cavity with the adjacent slot, such that the signals in each cavity are in phase with one another and each cavity functions as a live accelerating cavity. The resonance frequency of the slot is the comparable to the resonance frequency of the cavities, resulting in coupling of the cavities while also eliminating the need for side-cavity or other off-axis coupling cavities.

The invention discloses a real-time detecting method and system for multi-leaf collimator blade position of a linear accelerator. The method comprises the following steps: processing the video collected by two routes of the video collectors, obtaining the actual movement state and position of the multi-leaf collimator; and comparing with the set movement state and position of the multi-leaf collimator, and realizing the position precision detection to the multi-leaf collimator. The method is capable of collecting the movement video of the collimator blade, performing the image processing to the image of the collected video, obtaining the actual displacement of the collimator blade in the image; and comparing with the planed displacement of the collimator blade, obtaining the displacement error, and alarming while the displacement error exceeds the error range. The method has higher precision, and the blade positioning situation can be displayed online in real time during the self-inspection or radiotherapy. The requirement of the hardware is lower, the system cost is low, and the system can be repeatedly used. The system does not need other operates after the success of system installation and debugging, a related person can learn easily, and the using is convenient.

A radiation shielding arrangement for shielding high-energy neutron radiation and gamma radiation from high-energy particle accelerators or storage rings includes a shielding element made of water-containing material, for example with chemically bound water or water of crystallization, in particular gypsum. The water component of the material preferably makes up at least 5, 10 or 20 percent by weight. The hydrogen nuclei or protons contained therein moderate neutrons in a virtually ideal manner because of the almost identical mass and the maximum pulse transformation associated with this.

A charged particle beam transport system and method for linear accelerators includes a lens stack having two electrodes serially arranged along an acceleration axis between a charged particle source, and a linear accelerator. After producing and extracting a bunch of charged particles (i.e. particle beam) from the particle source, a voltage difference between the two electrodes is ramped in time to longitudinally compress the particle beam to be shorter than the pulsewidth of acceleration pulses produced in the accelerator. Additional electrodes may be provided in the lens stack for performing transverse focusing of the charged particle bunch and controlling a final beam spot size independent of the current and energy of the particle beam. In a traveling wave accelerator embodiment having a plurality of independently switchable pulse-forming lines, beam transport can also be controlled by triggering multiple adjacent lines simultaneously so that the physical size of the accelerating electric field is longer than the charged particle bunch, as well as by controlling trigger timing of the pulse-forming lines to perform alternating phase focusing.

The invention discloses a particle injection system and an annular particle accelerator. The particle injection system adopts jumping magnet to provide a pulse magnetic field having a preset cycle to an injection beam, and the jumping of the transmission speed and the transmission direction of the injection beam occur, when the injection beam passes through the incident gap of the jumping magnet, and the jumping of the emittance phase ellipse of the injection beam occurs, and therefore the emittance phase ellipse of the injection beam falls into the acceptability phase ellipse of the annular particle accelerator, and the injection process of the injection beam is completed. The ratio between pulse width of the pulse magnetic field provided by the jumping magnet and the circling cycle of the storage beam of the particle accelerator is smaller than a set value, and therefore the injection beam can be captured by the radio frequency acceleration electric field of the annular particle accelerator after entering the annular particle accelerator with help of a horizontal oscillation amplitude damping oscillation attenuation process. Because the pulse width of the pulse magnetic field is small, disturbances on the storage beam of the annular particle accelerator cannot be caused by the pulse magnetic field.

Standing-wave linear accelerators (linac) having a plurality of accelerating cavities and which do not have any auxiliary cavities are provided. Such linacs are useful for industrial applications such as radiography, cargo inspection and food sterilization, and also medical applications such as radiation therapy and imaging. In one embodiment, the linac includes an electron gun for generating an electron beam, and a plurality of accelerating cavities which accelerates the electron beam by applying electromagnetic fields generated by a microwave source. At least two adjacent accelerating cavities of the plurality of accelerating cavities are coupled together by at least one resonant iris. The electromagnetic fields resonate through the plurality of accelerating cavities and the at least one resonant iris.

The invention provides a system for measuring the beam flow intensity of a particle accelerator. The system comprises a dual-chamber chamber-type BPM and an ICT both arranged on a particle accelerator. The BPM comprises two reference chambers, each of which comprises a pair of probes on two sides respectively. The system also comprises a pair of differentiators, a mixer, a low-pass filter and a data collector. The mixer, the low pass filter and the data collector are connected in series successively. The pair of differentiators are connected between the BPM and the mixer parallelly. The system overcomes the defect in the prior art that a common mode TM010 signal must be transmitted for a long distance to the outside of a tunnel for mixing with a downconverted local oscillator source so that the signal is attenuated and is sensitive to the indoor and outdoor temperature difference, so that the measurement precision is improved.