Varian Medical Systems, Inc.

Varex Imaging Corporation

Gongyin Chen

Robert Edward Drubka

Timothy R Fox

John C Turner

Douglas W Eaton

David T Nisius

Kevin Matthew Holt

Kenneth Todd Romriell

David Alan Howell

Paul Bjorkholm

Martin Hu

John Stammetti

Zane J Wilson

Michael Z Duncan

Kevin Holt

These various embodiments serve to facilitate interlaced amplitude pulsing using a hard-tube type pulse generator having at least one energy-storage unit each comprising at least one energy-storing capacitor. Generally speaking, this comprises controlling an amount of energy withdrawn from the energy-storage unit and provided to an output load to form productive electric pulses by controlling at least one of: (1) energy replenishment; and (2) non-productive energy withdrawal of the energy-storage unit, to thereby achieve a series of productive interlaced amplitude electric pulses.

Method and apparatus for interlaced amplitude pulsing using a hard-tube type pulse generator

A method of operating an acceleration system comprises injecting charged particles into an RF accelerator, providing RF power to the accelerator, and accelerating the injected charged particles. The accelerated charged particles may impact a target to generate radiation. The RF power is based, at least in part, on past performance of the system, to compensate, at least partially, for dose and/or energy instability. A controller may provide a compensated control voltage ('CCV') to an electric power source based on the past performance, to provide compensated electric power to the RF source. A decreasing CCV, such as an exponentially decreasing CCV, may be provided to the electric power source during beam on time periods. The CCV to be provided may be increased, such as exponentially increased toward a maximum value, during beam off time periods. The controller may be configured by a compensation circuit and/or software. Systems are also described.

Charged particle accelerator systems including beam dose and energy compensation and methods therefor

Radiation scanning systems providing multiple views of an object in different planes and a reconstruction algorithm for reconstructing quasi-three-dimensional images from a limited number of views. A system may include bend magnets to direct accelerated charged particles to multiple targets in different viewing locations. Another system collimates radiation generated by a plurality of radiation sources into multiple beams for scanning an object at multiple angles. The object may be a cargo container, for example. The reconstruction algorithm uses an optimization algorithm and imaging and feasibility models to reconstruct quasi-three-dimensional images from the limited number of views.

Systems and methods for multi-view imaging and tomography

Variable pulse frequency during an output session of a betatron device and adjustable energy from pulse to pulse are provided. A different bias magnetic field may be used for different cycles of an output session, thereby providing different pulse energies. In one example, the bias field can be switched from a positive value to zero, with energy stored in a storage device when the bias field is zero. The bias field can also be used to expand electrons from a stable orbit when the bias field is decreased. For variable pulse frequency, when a current in the swing coils decreases to zero, the swing coils can be disengaged from a storage device for an adjustable time before re-engaging for a next cycle, thereby adjusting the frequency. In addition, radiation dose output can be adjusted by varying a length of time for the injection of electrons into a betatron.

Interlaced multi-energy betatron with adjustable pulse repetition frequency

A RF accelerator system includes an accelerator, a RF source coupled to the accelerator for providing RF power to the accelerator, a control for adjusting a frequency of the RF power provided by the RF source through a frequency range, and a sensor for sensing a response resulted from an operation of the accelerator based at least in part on the adjusted frequency of the RF power through the frequency range. A method of diagnosing a RF spectrum in an accelerator system includes providing RF power to an accelerator, adjusting a frequency of the RF power through a frequency range, and sensing a response resulted from an operation of the accelerator, the response being based at least in part on the adjusted frequency of the RF power through the frequency range.

On board diagnosis of RF spectra in accelerators

A method for generating stabilized particle acceleration by a radio-frequency (RF) accelerator is described, comprising operating the accelerator in a warm-up mode during a warm-up time period, without injecting charged particles or without accelerating injected charged particles, and operating the accelerator in a beam-on mode during a beam-on time period after the warm-up time period, to accelerate charged particles injected by the charged particle source. Automatic frequency control to match an expected frequency of the accelerator during the beam-on time period, prior to the start of the beam-on time period, for stability, is also described.

Accelerator system stabilization for charged particle acceleration and radiation beam generation

Multi-energy radiation sources comprising charged particle accelerators driven by power generators providing different RF powers to the accelerator, capable of interlaced operation, are disclosed. Automatic frequency control techniques are provided to match the frequency of RF power provided to the accelerator with the accelerator resonance frequency. In one example where the power generator is a mechanically tunable magnetron, an automatic frequency controller is provided to match the frequency of RF power pulses at one power to the accelerator resonance frequency when those RF power pulses are provided, and the magnetron is operated such that frequency shift in the magnetron at the other power at least partially matches the resonance frequency shift in the accelerator when those RF power pulses are provided. In other examples, when the power generator is a klystron or electrically tunable magnetron, separate automatic frequency controllers are provided for each RF power pulse. Methods and systems are disclosed.

Interlaced multi-energy radiation sources

At least three radiation-detection views are used to facilitate identifying material as comprises an object being assessed along a beam path relative to that object. This comprises developing a first radiation-detection view () as corresponds to the material along the beam path, a second radiation-detection view () as corresponds to the material along substantially the beam path, and at least a third radiation-detection view () as corresponds to the material along substantially the beam path. At least one of the source spectra and detector spectral responses used for these radiation-detection views are different from one another for each view. One then uses () these radiation-detection views to identify the material by, at least in part, differentiating the material from other possible materials.

Method and apparatus to facilitate using multiple radiation-detection views to differentiate one material from another

An x-ray-based radiation imaging apparatus () for use in imaging an object () can comprise a source of x-rays () having an output radiation intensity control input and a radiation intensity controller () operably coupled thereto. This radiation intensity controller can have a control output () that is operably coupled to the output radiation intensity control input and an object information input (). So configured, the radiation intensity controller can dynamically adjust radiation intensity as output by the source of x-rays as a function of information regarding the object itself.

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Henderson, NV, United States of America

Gongyin Chen