Mevion Medical Systems, Inc.

Still River Systems Incorporated

Kenneth P Gall

Stanley J Rosenthal

Gerrit Townsend Zwart

Jan Van Der Laan

Gordon Row

Charles D O'Neal, Iii

Michael J Ahearn

Alan P Sliski

Ken Yoshiki Franzen

Adam C Molzahn

Thomas C Sobczynski

James Cooley

Michael Busky

Stanislaw P Sobczynski

Charles D Iii O'NEAL

Charles D O'NEAL Iii

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.

Interrupted particle source

A system includes a patient support and an outer gantry on which an accelerator is mounted to enable the accelerator to move through a range of positions around a patient on the patient support. The accelerator is configured to produce a proton or ion beam having an energy level sufficient to reach a target in the patient. An inner gantry includes an aperture for directing the proton or ion beam towards the target.

Inner gantry

A synchrocyclotroncomprisesincludesa 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 voltageand orand/orcurrent 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. The programmable waveform generator can adjust at least one of the oscillating voltage input, the voltage on the injection electrode and the voltage on the extraction electrode according to beam intensity and in response to changes in resonant conditions.

Programmable radio frequency waveform generator for a synchrocyclotron

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.

Magnetic field regenerator

An example particle therapy system includes the following: a gantry that is rotatable relative to a patient position; a particle accelerator mounted to the gantry, where the particle accelerator is for outputting a particle beam essentially directly to the patient position; and a control system to receive a prescription and to generate machine instructions for configuring one or more operational characteristics of the particle therapy system. At least one of the operational characteristics relates to a rotational angle of the gantry relative to the patient position.

Controlling particle therapy

In an example, a synchrocyclotron includes a particle source to provide pulses of ionized plasma to a cavity; a voltage source to provide a radio frequency (RF) voltage to the cavity to accelerate particles from the plasma column outwardly; and an extraction channel to receive a beam of particles from the cavity for output from the particle accelerator. The particle source is configured to control pulse widths of the ionized plasma in order to control an intensity of the beam of particles. This example synchrocyclotron may include one or more of the following features, either alone or in combination.

Controlling intensity of a particle beam

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.

Adjusting energy of a particle beam

An example particle therapy system includes a particle accelerator to output a particle beam, where the particle accelerator includes: a particle source to provide pulses of ionized plasma to a cavity, where each pulse of the particle source has a pulse width corresponding to a duration of operation of the particle source to produce the corresponding pulse, and where the particle beam is based on the pulses of ionized plasma; and a modulator wheel having different thicknesses, where each thickness extends across a different circumferential length of the modulator wheel, and where the modulator wheel is arranged to receive a precursor to the particle beam and is configured to create a spread-out Bragg peak for the particle beam.

Control system for a particle accelerator

An example particle accelerator includes a coil to provide a magnetic field to a cavity; a cryostat comprising a chamber for holding the coil, where the coil is arranged in the chamber to define an interior region of the coil and an exterior region of the coil; magnetic structures adjacent to the cryostat, where the magnetic structures have one or more slots at least part-way therethrough; and one or more magnetic shims in one or more corresponding slots. The one or more magnetic shims are movable to adjust a position of the coil by changing a magnetic field produced by the magnetic structures.

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Harvard, MA, United States of America

Kenneth P Gall