A radiotherapy system includes: a waveguide, an adjustable waveguide, and a non-reciprocal circuit element. The waveguide transmits a high-frequency wave from a high-frequency power source to an acceleration tube. The adjustable waveguide is included in said waveguide and transforms a part of said waveguide. The non-reciprocal circuit element is provided between said acceleration tube and said adjustable waveguide in said waveguide. Said acceleration tube accelerates charged particles for generating therapeutic radiation by using said high-frequency wave.

Radiotherapy system for performing radiotherapy with presice irradiation

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

An accelerator (10) for accelerating a particle beam (12) includes a main body (70) having a plurality of electromagnetic cavities (16) coupled in series, and a first coupling body (21) having a first side cavity coupled to one of the electromagnetic cavities (16) through a first opening (22), and to another of the electromagnetic cavities (16) through a second opening (22), wherein the first opening and the second opening have different configurations. The accelerator further includes a pair of conductive capacitively coupled noses (24) secured to side walls of the first coupling body, wherein the pair of noses (24) have equal lengths.

Standing wave particle beam accelerator

Provided herein are systems and methods for operating a traveling wave linear accelerator to generate stable electron beams at two or more different intensities by varying the number of electrons injected into the accelerator structure during each pulse by varying the electron beam current applied to an electron gun The electron beams may be used to generate x-rays having selected doses and energies, which may be used for cargo scanning or radiotherapy applications

Systems and methods for cargo scanning and radiotherapy using a traveling wave linear accelerator based x-ray source using pulse width to modulate pulse-to-pulse dosage

An electromagnetic wave having a phase velocity and an amplitude is provided by an electromagnetic wave source to a traveling wave linear accelerator. The traveling wave linear accelerator generates a first output of electrons having a first energy by accelerating an electron beam using the electromagnetic wave. The first output of electrons can be contacted with a target to provide a first beam of x-rays. The electromagnetic wave can be modified by adjusting its amplitude and the phase velocity. The traveling wave linear accelerator then generates a second output of electrons having a second energy by accelerating an electron beam using the modified electromagnetic wave. The second output of electrons can be contacted with a target to provide a second beam of x-rays. A frequency controller can monitor the phase shift of the electromagnetic wave from the input to the output ends of the accelerator and can correct the phase shift of the electromagnetic wave based on the measured phase shift.

Traveling wave linear accelerator comprising a frequency controller for interleaved multi-energy operation

The frequency of a microwave source, such as a magnetron of klystron, is locked to the variable frequency of a resonant load. A sample of the microwave power incident on the load is derived from the magnetron and compared in a phase comparator with a sample of the microwave energy reflected from the resonant load to derive an error signal representative of the frequency departure of the frequency of the microwave source from the resonant frequency of the load. The error signal is utilized for driving a tuner for tuning the frequency of the microwave source to the frequency of the load. In a preferred embodiment the phase comparator comprises a three db four port microwave hybrid coupler having a pair of outputs, the outputs of which are rectified by microwave diodes and subtracted to produce the error signal. The length of the transmission path from the microwave source to the phase comparator circuit is made longer than the length of the transmission path from the microwave source to the load and back to the phase comparator circuit in order to skew the frequency discriminator output characteristic of the phase comparator in order to eliminate ambiguities in the sense of the error signal at frequencies far removed from the resonant frequency of the load.

G Meddaugh

Papers

Microwave automatic frequency control circuit