Abstract: A circuit is operative to extract electromagnetic wave energy from the ground via a resonant transformer in which resonance is triggered by electrical charge arcing across a spark gap. A center tap of the primary winding of the transformer is capacitively coupled to an electrode buried in the ground. In-rush current from the ground electrode is converted to a useful form (e.g., one- or three-phase 60 Hz AC) by a power conversion circuit connected to the secondary winding of the resonant transformer. The ground electrode of the capacitor coupling the grounded electrode to the center tap primary winding is the shield of a Faraday cage enclosing the resonant transformer, spark gap, and a high-voltage power supply exciting the spark gap.

Abstract: A superconducting magnet system and a cyclotron using the same. The superconducting magnet system includes a cryogenic device, a superconducting device and a protecting module. The cryogenic device includes a refrigerating machine and a cryogenic container assembly. The cryogenic container assembly includes a first container end, a connecting tube and a second container end. The first container end is communicated with the second container end through the connecting tube. The superconducting device includes a superconducting coil arranged in the first container end and immersed in a liquid or gaseous cooling medium. The protecting module is connected to the superconducting coil and is configured to protect the superconducting coil if the superconducting coil suffers a quench.

Abstract: There is provided a cyclotron which accelerates a charged particle in an orbital trajectory to emit a charged particle beam. The cyclotron includes a magnetic pole that generates a magnetic field required for accelerating the charged particle, and a magnetic channel portion having a magnetic channel disposed on an outer peripheral portion of the orbital trajectory to guide the charged particle beam to an extraction trajectory and to focus the charged particle beam. The magnetic channel portion is attached to the magnetic pole.

Abstract: A cryogenic magnet structure includes at least two superconducting coils that are substantially symmetric about a central axis and on opposite sides of a median plane. At least one cryostat contains the superconducting coils; and a magnetic yoke surrounds the superconducting coils and contains at least a portion of a chamber, wherein the median plane extends through the chamber. At least one integral maintenance boot assembly is in thermal contact with the superconducting coils and is configured to preserve a sealed vacuum in the cryostat; and a cryogenic refrigerator is in thermal contact with the maintenance boot assembly and is configured to cool the superconducting coils below their critical superconducting temperatures and is configured for removal from thermal contact with the integral maintenance boot assembly without breaking the sealed vacuum in the cryostat.

Abstract: A device for applying a constant magnetic field to a volume of interest (VOI) has been developed. At least one magnetic field source and a permeable yoke, which guides the magnetic flux generated by this magnetic field source into the volume of interest (VOI). The yoke is guided through at least one closed conductor loop, which can be switched to the superconducting state so that, in the superconducting state of the conductor loop, a change in the flux through the yoke effects a current counteracting this change along the conductor loop. It has been identified that, in this way, the stabilizer for the magnetic field can be spaced so far apart from the volume of interest (VOI) that the field distribution in this volume is virtually no longer influenced. At the same time, the quality of the stabilization is also improved, since the conductor loop is no longer exposed to the entire magnetic field prevailing in the volume of interest (VOI).

Abstract: A cryogenic magnet structure includes at least two superconducting coils, a magnetic yoke, and first and second cryostats. The superconducting coils are substantially symmetric about a central axis, wherein the superconducting coils are on opposite sides of a median plane. The magnetic yoke surrounds the superconducting coils and contains at least a portion of a chamber, wherein the median plane extends through the chamber. The first cryostat contains a first of the superconducting coils, and the second cryostat contains a second of the superconducting coils. The second cryostat is distinct from the first cryostat, and the first and second cryostats are on opposite sides of the median plane in the chamber.

Abstract: An example particle accelerator includes the following: a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, where the cavity has a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity; an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel. The magnetic field is at least 6 Tesla and the magnetic field bump is at most 2 Tesla.

Abstract: Embodiments of the present invention disclose methods and systems for performing particle acceleration using a cyclotron RF resonator with an asymmetrical fixed tuner. A cyclotron RF resonator includes a single shorting plate tuner inside and a fixed short stem, and does not require top-bottom mirror symmetry. Small movements in relation to the wavelengths of the maximum acceleration voltage is bound by the capacitance of the accelerating surfaces. As such, the resonator may perform particle acceleration using asymmetrical tuning to reduce design complexity, cost of maintenance, fabrication and installation complexity, failure rate, and software complexity (e.g., control software), for example.

Abstract: The present disclosure relates to a magnet pole for an isochronous sector-focused cyclotron having hill and valley sectors alternatively distributed around a central axis, Z, each hill sector having an upper surface bounded by four edges: an upper peripheral edge, an upper central edge, a first and a second upper lateral edges, and a peripheral surface extending from the upper peripheral edge to a lower peripheral line. The upper peripheral edge of at least one hill sector may further include a concave portion with respect to the central axis defining a recess extending at least partially over a portion of the peripheral surface of the corresponding hill sector.

Abstract: An arrangement includes a superconducting split ring resonator, a cryostat, and a copper coil. The resonator is arranged in the cryostat and includes at least one ring-shaped conductor made of a superconducting material and including an opening and a taper. The copper coil may be used to transmit a MRI excitation signal. This signal causes a current to be induced in the conductor that leads to the breakdown of the superconductivity. The conductor is detuned and therefore no longer develops an interfering effect. It is possible for the effect of the breakdown of superconductivity to be used for detuning in a targeted manner. After the transmission is complete, the conductor returns into the superconducting state and acts as a superconducting reception antenna for the MRI measurement signal. The copper coil is inductively coupled to the conductor and configured to read out the signal induced in the conductor.

Abstract: A superconducting magnet device includes a superconducting coil, a radiation shield, a refrigeration unit, a vacuum case, an electrode member, and a conductive member. The vacuum case includes a case body housing the superconducting coil and a surrounding cover that surrounds the refrigeration unit. The conductive member includes a contact portion having a sleeve-shaped outer circumferential face and thermally contactable with an inner face of the surrounding cover via an insulating material. The surrounding cover includes a heat radiating part including at least a surface of a portion of the surrounding cover overlapping the contact portion in a radial direction of the surrounding cover. Thermal conductivity of the heat radiating part is higher than thermal conductivity of stainless steel.

Abstract: The invention comprises an apparatus and method of use thereof for extracting ions from an ion source, such as for use in cancer treatment or tomographic imaging. The extraction apparatus uses a triode extraction system, with the ion source and/or first electrode held at a first potential; an extraction electrode held at a second potential; and a gating electrode, positioned between the ion source and the extraction electrode, oscillating and/or alternating between a first suppression potential proximate that of the ion source potential and a second extraction potential between the ion source potential and the extraction electrode potential. Optionally, the ion source comprises an electron cyclotron resonance ion source.

Abstract: A superconducting magnet device includes a superconducting coil, a radiation shield, a vacuum case, an electrode member, and a conductive member. The conductive member includes an oxidized lead disposed in the radiation shield. The vacuum case includes a case body having an outer opening and an outer lid that is detachably attachable to the case body. The radiation shield includes a shield body having an inner opening and an inner lid that is detachably attachable to the shield body. The inner opening is formed in the region of the shield body that overlaps a portion of the outer opening when viewed in the direction from the outer opening to the oxidized lead.

Abstract: An isochronous cyclotron includes at least two superconducting coils, a magnetic yoke surrounding the coils and containing at least a portion of a beam chamber, a plurality of superconducting flutter coils on each side of the median acceleration plane, a non-magnetic reinforcement structure filling the valleys between the superconducting flutter coils so as to maintain the positioning of the superconducting flutter coils, internal reinforcement structures mounted inside the superconducting flutter coils, and a cryogenic refrigerator thermally coupled with the superconducting coils and with the magnetic yoke.

Abstract: Radio-frequency (RF) electrode for a cyclotron. The RF electrode includes a hollowed dee having first and second surfaces that oppose each other and define a gap therebetween. The hollowed dee is configured to be electrically controlled to direct a beam of charged particles through the gap and along an orbit plane of the cyclotron. The orbit plane extends parallel to the first and second surfaces through the gap. The RF electrode also includes a bridge structure that is coupled to and extends away from the hollowed dee. The bridge structure includes a side wall that defines an interior cavity of the bridge structure. The side wall has a particle opening therethrough that coincides with or is proximate to the orbit plane such that the particle opening receives neutral particles from an orbit of the charged particles.

Abstract: Cyclotron for accelerating charged particles around an axis, comprising an electromagnet with an upper pole and a lower pole, producing a magnetic field in the direction of said axis; a Dee electrode assembly and a counter Dee electrode assembly separated from each other by a gap for accelerating said charged particles and a pair of ion sources located in a central region of the cyclotron. Said ion sources are located at a distance of said axis such that the particles emitted from the first ion source pass between said first and second ion sources after a path of half a turn, and radially outwards of the second ion source after a path of three half-turns, and reciprocally.

Abstract: Various emitters and emitter systems are disclosed. For instance, in various embodiments, an emitter can comprise a substrate, an insulator bonded to the substrate, a graphene layer bonded to the insulator, and a first electrical contact and a second electrical contact. The first electrical contact can be bonded over a first portion of the graphene layer, and the second electrical contact can be bonded over a second portion of the graphene layer. The graphene layer electrically couples the first electrical contact and the second electrical contact and is configured to receive the application of a pulsed input voltage between the first electrical contact and the second electrical contact and to radiate radio frequency (RF) energy. An emitter system can comprise a plurality of emitters, each disposed on a single integrated circuit.

Abstract: A magnetron sputtering electrode for use in a rotatable cylindrical magnetron sputtering device, the electrode including a cathode body defining a magnet receiving chamber and a cylindrical target surrounding the cathode body. The target is rotatable about the cathode body. A magnet arrangement is received within the magnet receiving chamber, the magnet arrangement including a plurality of magnets. A shunt is secured to the cathode body and proximate to a side of the magnet arrangement, the shunt extending in a plane substantially parallel to the side of the magnet arrangement. A method of fine-tuning a magnetron sputtering electrode in a rotatable cylindrical magnetron sputtering device is also disclosed.

Abstract: A particle beam therapy system is disclosed which includes: a synchrotron accelerating a charged particle beam injected from a pre-accelerator up to a predetermined energy level before applying a high-frequency voltage to an extraction device to extract the charged particle beam caused to exceed a stability limit; a beam transportation system transporting the charged particle beam extracted from the synchrotron up to a treatment room, and an irradiation device irradiating a patient in the treatment room with the charged particle beam in conformity to the patient's tumor shape. The synchrotron has functionality to accelerate or decelerate the charged particle beam successively to extract the charged particle beam at a plurality of energy levels during an extraction phase of the synchrotron, the beam transportation system further having functionality to block off an unnecessary charged particle beam extracted from the synchrotron during acceleration or deceleration.

Abstract: When controlling the ejection of a charged particle beam from a synchrotron, a radiofrequency voltage is applied, which serves as the radio-frequency voltage to be applied to an ejection radio-frequency electrode equipping the synchrotron, and which is constituted by a first radio-frequency voltage for increasing an oscillation amplitude in such a way as to exceed a stable limit in order to eject to the exterior of the synchrotron a beam that circles inside the synchrotron, and a second radio-frequency voltage for preferentially ejecting a charged particle beam that circles in the vicinity of the stable limit, with the amplitude value of the second radiofrequency voltage being controlled in such a way that the amplitude value is 0 prior to the beam ejection start, the amplitude value increases gradually from the beam ejection start, and, once a predetermined amplitude value has been reached, this value is maintained.

Abstract: A particle accelerator including an electrical field system and a magnetic field system that are configured to direct a particle beam of charged particles along a designated path within an acceleration chamber. The particle accelerator also includes a foil holder having a beam window and a positioning slot that at least partially surrounds the beam window. The positioning slot is dimensioned to hold an extraction foil such that the extraction foil extends across the beam window and into the path of the charged particles. The positioning slot is defined by interior reference surfaces that face the extraction foil and retain the extraction foil within the positioning slot. The reference surfaces permit the extraction foil to move relative to the reference surfaces when the particle beam is incident on the extraction foil.

Abstract: An example particle accelerator includes the following: a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, where the cavity has a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity; an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel. The magnetic field is at least 6 Tesla and the magnetic field bump is at most 2 Tesla.

Abstract: The invention specifies the use of feedback in the radio frequency (RF) drive for a synchrocyclotron, controlling the phase and/or amplitude of the accelerating field as a means to assure optimal acceleration of the beam, to increase the average beam current and to alter the beam orbit in order to allow appropriate extraction as the beam energy is varied. The effect of space charge is reduced by rapid acceleration and extraction of the beam, and the repetition rate of the pulses can be increased. Several means are presented to monitor the phase of the beam in synchrocyclotrons and to adjust the phase and amplitude of the RF to optimize the acceleration of the beam and to adjust the extraction and injection of the beam. Also, the use of a pulsed ion source that matches the acceptance window of the synchrocyclotron is described.

Abstract: The invention specifies the use of feedback in the radio frequency (RF) drive for a synchrocyclotron, controlling the phase and/or amplitude of the accelerating field as a means to assure optimal acceleration of the beam, to increase the average beam current and to alter the beam orbit in order to allow appropriate extraction as the beam energy is varied. The effect of space charge is reduced by rapid acceleration and extraction of the beam, and the repetition rate of the pulses can be increased. Several means are presented to monitor the phase of the beam in synchrocyclotrons and to adjust the phase and amplitude of the RF to optimize the acceleration of the beam and to adjust the extraction and injection of the beam. Also, the use of a pulsed ion source that matches the acceptance window of the synchrocyclotron is described.

Abstract: An example particle accelerator includes a coil to provide a magnetic field to a cavity; a particle source to provide a plasma column to the cavity; a voltage source to provide a radio frequency (RF) voltage to the cavity to accelerate particles from the plasma column, where the magnetic field causes particles accelerated from the plasma column to move orbitally within the cavity; an enclosure containing an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and a structure arranged proximate to the extraction channel to change an energy level of the received particles.

Abstract: A magnet structure for use in a circular ion accelerator, such as e.g. a synchrocyclotron comprises a cold-mass structure including superconducting magnetic coils (20, 25), at least one dry cryocooler unit (10, 11, 12, 13) coupled with the cold-mass structure for cooling the latter and a magnetic yoke structure (30) with a return yoke (35) configured radially around said coils (20, 25). The return yoke (35) comprises an opening in which said dry cryocooler unit (10, 11, 12, 13) is received so as to be in thermal contact with said cold-mass structure.

Abstract: An example particle accelerator may include the following: a voltage source to sweep a radio frequency (RF) voltage in a cavity to accelerate particles from a plasma column, where the cavity has a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity, and where the magnetic field has flux that bows at edges of the cavity; a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to an extraction point, where the regenerator is located at a radius in the cavity relative to the plasma column; and ferromagnetic arrangements located in the cavity proximate to the radius, where each ferromagnetic arrangement provides a magnetic field bump, and where ferromagnetic arrangements adjacent to the regenerator are separated from the regenerator by a space.

Abstract: There is provided a cyclotron including: a hollow yoke; first and second poles disposed in the yoke; an ion source that generates an ion; a buncher of which at least a part enters the yoke and which adjusts a density of an ion beam, which is emitted from the ion source, in a traveling direction; and an inflector that deflects an ion beam having passed through the buncher to make the ion beam incident on a median plane.

Abstract: The present disclosure relates to a cyclotron. Embodiments of the present disclosure may include an upper and lower magnet pole, an upper and lower superconducting coil arranged around each of the magnetic poles, a ring-shaped magnetic return yoke, a beam chamber between the upper and lower magnetic poles having one or more electrodes configured to accelerate ions moving substantially in the median plane, and a cryostat. The ring-shaped magnetic return yoke and the coils may form a cold mass contained within the cryostat. Further, the cryostat may not contain the upper and lower poles.

Abstract: A synchrocyclotron includes magnetic structures that define a resonant cavity, a source to provide particles to the resonant cavity, a voltage source to provide radio frequency (RF) voltage to the resonant cavity, a phase detector to detect a difference in phase between the RF voltage and a resonant frequency of the resonant cavity that changes over time, and a control circuit, responsive to the difference in phase, to control the voltage source so that a frequency of the RF voltage substantially matches the resonant frequency of the resonant cavity.

Abstract: A cyclotron includes a superconductive coil that is disposed in a vacuum vessel, a cooling unit that cools the superconductive coil, a basic support member that is installed in the vacuum vessel and supports the superconductive coil in the vacuum vessel, and a support member for quenching that is fixed to one of the superconductive coil and the vacuum vessel and forms a predetermined gap with the other thereof.

Abstract: Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce useful products, such as fuels. For example, systems can use feedstock materials, such as cellulosic and/or lignocellulosic materials and/or starchy materials, to produce ethanol and/or butanol, e.g., by fermentation.

Abstract: Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce useful products, such as fuels. For example, systems can use feedstock materials, such as cellulosic and/or lignocellulosic materials and/or starchy materials, to produce ethanol and/or butanol, e.g., by fermentation.

Abstract: Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce useful products, such as fuels. For example, systems can use feedstock materials, such as cellulosic and/or lignocellulosic materials and/or starchy materials, to produce ethanol and/or butanol, e.g., by fermentation.

Abstract: There is provided a cyclotron including: a hollow yoke; first and second poles disposed in the yoke; an ion source that generates an ion; a buncher of which at least a part enters the yoke and which adjusts a density of an ion beam, which is emitted from the ion source, in a traveling direction; and an inflector that deflects an ion beam having passed through the buncher to make the ion beam incident on a median plane.

Abstract: The invention comprises a charged particle beam path coupling an injector, synchrotron accelerator, beam transport system, targeting system, and/or patient interface method and apparatus. Preferably, the injector comprises: a negative ion beam source, a two phase ion source vacuum system, an ion beam focusing lens, and/or a tandem accelerator. Preferably, the synchrotron comprises turning magnets, edge focusing magnets, magnetic field concentration magnets, winding and correction coils, flat magnetic field incident surfaces, and/or extraction elements.

Abstract: The invention comprises a patient positioning method and apparatus used in conjunction with multi-axis charged particle or proton beam radiation therapy of cancerous tumors. The patient positioning system is used to translate the patient and/or rotate the patient into a zone where the proton beam can scan the tumor using a targeting system. The patient positioning system is optionally used in conjunction with systems used to constrain movement of the patient, such as semi-vertical, sitting, or laying positioning systems.

Abstract: Superconducting rf is limited by a wide range of failure mechanisms inherent in the typical manufacture methods. This invention provides a method for fabricating superconducting rf structures comprising coating the structures with single atomic-layer thick films of alternating chemical composition. Also provided is a cavity defining the invented laminate structure.

Abstract: Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce useful products, such as fuels. For example, systems can use feedstock materials, such as cellulosic and/or lignocellulosic materials and/or starchy materials, to produce ethanol and/or butanol, e.g., by fermentation.

Abstract: The invention relates to treatment of solid cancers. More particularly, the invention relates to a combined rotation/raster method, referred to as multi-field charged particle cancer therapy. The system uses a fixed orientation proton source relative to a rotating patient to yield tumor irradiation from multiple directions. The system combines layer-wise tumor irradiation from many directions with controlled energy proton irradiation to deliver peak proton beam energy within a selected tumor volume or irradiated slice. Optionally, the selected tumor volume for irradiation from a given angle is a distal portion of the tumor. In this manner ingress Bragg peak energy is circumferentially spread about the tumor minimizing damage to healthy tissue and peak proton energy is efficiently, accurately, and precisely delivered to the tumor.

Abstract: The present invention relates to a stripping member for stripping electrons off a negatively charged particle beam at the periphery of a cyclotron for extracting a particle beam out of said cyclotron, said stripping member comprising a first stripper foil adapted for being located at the periphery of said cyclotron so that said particle beam passes through said first stripper foil, characterized in that it comprises a second stripper foil adapted for being located side-by-side with the first foil at the periphery of said cyclotron at a more peripheral radius than said first stripper foil so that said negatively charged particle beam passes through said second stripper foil when said first stripper foil is damaged.

Abstract: The invention comprises intensity control of a charged particle beam acceleration, extraction, and/or targeting method and apparatus used in conjunction with charged particle beam radiation therapy of cancerous tumors. Particularly, intensity of a charged particle stream of a synchrotron is described. Intensity control is described in combination with turning magnets, edge focusing magnets, concentrating magnetic field magnets, winding and control coils, and extraction elements of the synchrotron. The system reduces the overall size of the synchrotron, provides a tightly controlled proton beam, directly reduces the size of required magnetic fields, directly reduces required operating power, and allows continual acceleration of protons in a synchrotron even during a process of extracting protons from the synchrotron.

Abstract: The invention comprises a charged particle cancer therapy system or synchrotron system using one or more switches to introduce a corresponding one or more resistors into a circuit linking a power supply to a magnet or an inductor during an applied power recovery phase between acceleration cycles of the synchrotron, which reduces time of reduction in power from an active applied power to a power suitable for use with a subsequent injection of charged particles into the synchrotron.

Abstract: The invention comprises intensity control of a charged particle beam acceleration, extraction, and/or targeting method and apparatus used in conjunction with charged particle beam radiation therapy of cancerous tumors. Particularly, intensity of a charged particle stream of a synchrotron is described. Intensity control is described in combination with turning magnets, edge focusing magnets, concentrating magnetic field magnets, winding and control coils, and extraction elements of the synchrotron. The system reduces the overall size of the synchrotron, provides a tightly controlled proton beam, directly reduces the size of required magnetic fields, directly reduces required operating power, and allows continual acceleration of protons in a synchrotron even during a process of extracting protons from the synchrotron.

Abstract: The present invention relates to a cyclotron including two internal ion sources for the production of the same particles. The second ion source can be used as a spare ion source which strongly increases the uptime and the reliability of the cyclotron and reduces the maintenance interventions. Advantageously, the cyclotron is further characterized by an optimized close geometry of the different elements within the central region of the cyclotron. The cyclotron of the invention may be further characterized by an adaptation and optimization of the shape of first and second internal ion source to avoid particle losses during the first turn of acceleration. The cyclotron may be further characterized by an adaptation and optimization of the shape of the counter-Dee electrode assembly and possibly the Dee-electrode assembly in order to improve the acceleration field in-between the gaps.

Abstract: An electrode for fixed-frequency particle accelerators geometrically compensating for relativistic mass increase by placing the acceleration gap at the location of the particle at each peak of the accelerating electric field.

Abstract: The invention comprises a tandem accelerator method and apparatus, which is part of an ion beam injection system used in conjunction with multi-axis charged particle radiation therapy of cancerous tumors. The negative ion beam source includes an injection system vacuum system and a synchrotron vacuum system separated by a foil, where negative ions are converted to positive ions. The foil is sealed to the edges of the vacuum tube providing for a higher partial pressure in the injection system vacuum chamber and a lower pressure in the synchrotron vacuum system. Having the foil physically separating the vacuum chamber into two pressure regions allows for fewer and/or smaller pumps to maintain the lower pressure system in the synchrotron as the inlet hydrogen gas is extracted in a separate contained and isolated space by the injection partial vacuum system.

Abstract: The invention comprises a proton beam positioning method and apparatus used in conjunction with multi-axis charged particle radiation therapy of cancerous tumors. The proton beam verification system allows for monitoring of the actual proton beam position in real-time without destruction of the proton beam. The system includes a coating or thin layer substantially in contact with a foil covering the end of an exit nozzle or is a layer located after the x- and y-axis proton beam scanning controllers and before the patient. The coating yields a measurable spectroscopic response, spatially viewable by the detector, as a result of transmission by the proton beam. The proton beam position is monitored by the detector and compared to the calibration and/or treatment plan to verify accurate proton delivery to the tumor and/or as a proton beam shutoff safety indicator.

Abstract: A synchrocyclotron comprises includes a resonant circuit that includes electrodes having a gap therebetween across the magnetic field. An oscillating voltage input, having a variable amplitude and frequency determined by a programmable digital waveform generator generates an oscillating electric field across the gap. The synchrocyclotron can include a variable capacitor in circuit with the electrodes to vary the resonant frequency. The synchrocyclotron can further include an injection electrode and an extraction electrode having voltages controlled by the programmable digital waveform generator. The synchrocyclotron can further include a beam monitor. The synchrocyclotron can detect resonant conditions in the resonant circuit by measuring the voltage and or and/or current in the resonant circuit, driven by the input voltage, and adjust the capacitance of the variable capacitor or the frequency of the input voltage to maintain the resonant conditions.

Abstract: A synchrocyclotron includes magnetic structures to provide a magnetic field to a cavity, a particle source to provide a plasma column to the cavity, where the particle source has a housing to hold the plasma column, and where the housing is interrupted at an acceleration region to expose the plasma column, and a voltage source to provide a radio frequency (RF) voltage to the cavity to accelerate particles from the plasma column at the acceleration region.