Mevion Medical Systems, Inc.

Varian Associates, Inc.

Other

The Boc Group, Inc.

K.o. Devices, Inc.

Charles D O'Neal, Iii

Kenneth P Gall

Adam C Molzahn

Gerrit Townsend Zwart

Ken Yoshiki Franzen

Jan Van Der Laan

Stanley J Rosenthal

James Cooley

Thomas C Sobczynski

Michael Busky

Marsbed Hablanian

Paul A Keleher

John J Vincent

Leo J Blumle

An example particle therapy system includes: a particle accelerator to output a beam of charged particles; and a scanning system to scan the beam across at least part of an irradiation target. An example scanning system includes: a scanning magnet to move the beam during scanning; and a control system (i) to control the scanning magnet to produce uninterrupted movement of the beam over at least part of a depth-wise layer of the irradiation target so as to deliver doses of charged particles to the irradiation target; and (ii) to determine, in synchronism with delivery of a dose, information identifying the dose actually delivered at different positions along the depth-wise layer.

Scanning system

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

An example synchrocyclotron includes the following: a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a particle source; a coil to receive a variable electrical current and to generate a magnetic field that is at least 4 Tesla to cause the particles to move orbitally within the cavity; and an extraction channel to receive the accelerated particles and to output the received particles from the cavity. The particles that are output from the cavity have an energy that is variable based at least on the variable electrical current applied to the coil.

Particle accelerator that produces charged particles having variable energies

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

Scanning system for a particle therapy system

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.

Focusing a particle beam using magnetic field flutter

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.

Matching a resonant frequency of a resonant cavity to a frequency of an input voltage

An example particle accelerator includes the following: a resonant cavity in which particles are accelerated, where the resonant cavity has a background magnetic field having a first shape; and an extraction channel for receiving particles output from the resonant cavity. The extraction channel comprises a series of focusing regions to focus a beam of received particles. At least one of the focusing regions is a focusing element configured to alter a shape of the background magnetic field to a second shape that is substantially opposite to the first shape in the presence of a magnetic field gradient resulting from reduction of the background magnetic field from the resonant cavity to the extraction channel.

Focusing a particle beam

A circuit breaker test device for testing a circuit breaker, and also for testing the branch circuit of which the circuit breaker is a part. The circuit breaker test device includes a switch that controllably short-circuits the branch circuit. A controller causes the switch to short circuit the branch circuit. A timer, responsive to operation of the controller, causes the switch to cease short-circuiting the branch circuit after a particular test time. An impedance value of the branch circuit is determined. The controller is enabled only if the impedance value is within predetermined limits. The timer is capable of establishing a variable test time.

Circuit and circuit breaker tester

A circuit breaker tripper includes a first charging circuit for charging an RC shorting time control circuit. A relay is connected to a pair of probes that are connected to an active line which enables a charging of the RC shorting time control circuit. Activation of a switch causes a relay to apply a short circuit across the active line, thereby causing a tripping of the circuit breaker. At the same time, a discharge circuit is activated which causes the relay open the short circuit after a preset period. Since the circuit breaker tripper relies on enabling sufficient current flow through the circuit breaker to trip it, a test circuit is provided which enables operation of the tripper only if the branch circuit is within a safe operating range for the circuit breaker tripper.

Circuit breaker tester

The present invention provides a vacuum gauge having two integrated circuits connected in a half bridge circuit to register subatmospheric gas pressure from a change in thermal gas conductivity. One of the integrated circuits serves to generate an electrical current proportional to the ambient temperature and a function of its power output conducted by the gas. The other of the integrated circuits acts as a reference to generate an electrical current proportional to ambient temperature. The half bridge circuit acts to subtract the currents so that subatmospheric pressure can be read on an ammeter as a function of gas thermal conductivity.

Growing community of inventors

Bolton, MA, United States of America

Charles D O'Neal, Iii