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US 10,420,201 B2Granted
Linear accelerator system for stable pulsing at multiple dose levels
AssigneeETM Electromatic, Inc.
InventorsWilliam L. Nighan, Jr., Maarten Korringa, John Howard Rolin, Devin Kirk Henderlong
Life of this patent
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Abstract
A linac-based X-ray system for cargo scanning and imaging applications uses linac design, RF power control, beam current control, and beam current pulse duration control to provide stable sequences of pulses having different energy levels or different dose.
Claims20
An X-ray system for providing a plurality of X-ray pulses of controlled dose per pulse, each of the plurality comprising either different energy or different dose characteristics, comprising
- a linear accelerator having resonance with a bandwidth for outputting pulses of high energy electrons and configured to strike a target to thereby generate a plurality of X-ray pulses,
- a magnetron responsive to a first control signal for supplying RF energy pulses to the linear accelerator at a plurality of RF power levels with a corresponding plurality of frequencies,
- an electron gun driver, operating independently of the magnetron by being responsive to a second control signal different from the first control signal, for supplying to the linear accelerator pulses of a plurality of beam currents at times substantially corresponding to an associated one of the RF energy pulses at a plurality of RF power levels, and wherein the bandwidth of the linear accelerator resonance is sufficiently broad to allow coupling of the magnetron output to the linear accelerator at the plurality of RF power levels such that the energies of X-ray pulses resulting from at least two of the plurality of pulses of high energy electrons are at least 1 MeV apart and less than 5 MeV apart with controlled dose per pulse, at least one of the plurality of X-ray pulses is at a reduced dose relative to at least one other of the plurality of X-ray pulses and the reduced dose pulses are substantially within the range of 5× to 200× smaller than the pulses that are not reduced dose.
An X-ray system for providing X-ray pulses of controlled dose per pulse comprising
- a linear accelerator for outputting pulses of high energy electrons and configured to strike a target to thereby generate a plurality of X-ray pulses
- a magnetron responsive to a first control signal for supplying as an output RF energy pulses to the linear accelerator at at least three different RF power levels with a corresponding at least three frequencies,
- an electron gun driver, responsive to a second control signal different from the first control signal, for supplying to the linear accelerator pulses of at least three different beam currents at times substantially corresponding to the RF energy pulses at the at least three RF power levels, and wherein the bandwidth of the linear accelerator resonance is sufficiently broad to allow coupling of the magnetron output to the linear accelerator at the at least three RF power levels such that the energies of the X-ray pulses resulting from at least two of the three different beam currents are at least 1 MeV apart and less than 5 MeV apart with controlled dose per pulse and at least one of the plurality of X-ray pulses is at a reduced dose relative to at least one other of the plurality of X-ray pulses and the reduced dose pulses are substantially within the range of 5× to 200× smaller than the pulses that are not reduced dose.
An X-ray system for providing X-ray pulses of controlled dose per pulse comprising
- a linear accelerator having a triode gun,
- a control system,
- an RF source responsive to the control system to supply RF pulses to the linear accelerator,
- an electron gun driver connected to said triode gun, responsive to the control system but controlled independently of the RF source, for supplying to the linear accelerator pulses of a plurality of controllable beam currents at times substantially corresponding to RF pulses,
- the RF source and electron gun driver being configured cooperatively to strike a target and thereby to cause the generation of X-ray pulses of a first energy and dose for scanning a first region, and to cause the generation of X-ray pulses of a second energy and dose for scanning a second region and wherein the first dose is substantially in the range of 5× to 200× smaller than the second dose.
2 more elements
An X-ray system for providing a plurality of X-ray pulses of controlled dose per pulse, each of the plurality comprising either different energy or different dose characteristics, comprising
- a linear accelerator having resonance with a bandwidth for outputting pulses of high energy electrons and configured to strike a target to thereby generate a plurality of X-ray pulses,
- a magnetron responsive to a first control signal for supplying RF energy pulses to the linear accelerator of at least two RF power levels with a corresponding plurality of frequencies,
- an electron gun driver, operating independently of the magnetron by being responsive to a second control signal different from the first control signal, for supplying to the linear accelerator pulses of at least three beam currents at times substantially synchronous with the RF energy pulses, and wherein the bandwidth of the linear accelerator resonance is sufficiently broad to allow coupling of the magnetron output to the linear accelerator at the plurality of RF power levels such that the energies of X-ray pulses resulting from at least two of the plurality of pulses of high energy electrons are at least 1 MeV apart and less than 5 MeV apart with controlled dose per pulse, at least one of the plurality of X-ray pulses is at a reduced dose relative to at least one other of the plurality of X-ray pulses and the reduced dose pulses are substantially within the range of 5× to 200× smaller than the pulses that are not reduced dose.
Dependencies are inferred from the claim text.