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 doses.

A continuous wave (CW) electron accelerator for the treatment of industrial streams including an electron beam source, a modified high efficiency slot coupled cavity, at least one focusing magnet positioned surrounding the accelerator to contain the beam in the accelerator, an efficient radio frequency power supply means for supplying power of a radio frequency to the cavity to induce a TM01 accelerating mode in the cavity, an electron beam spreader or raster, a fixed magnet array or two-dimensional scanning magnet for deflecting the accelerated beam into a desired shape, and an exit window for extracting the deflected electron beam. The accelerator includes a graded-beta cavity to enable use with a low-power pulsed electron source. The accelerator benefits from a low wall-power loss accelerating cavity that is energized with efficient RF sources, enabling it to be operated in continuous wave mode.

A linear accelerator comprises side-coupled cavity cells configured to accelerate electrons with a radio frequency field. The field amplitude in the initial cells is lower than in the later cells, and the initial cells are shorter than the later cells. This creates a capture section where electrons are captured and bunched while experiencing low acceleration, followed by an acceleration section where the bunched electrons experience stronger acceleration.

A high-current, compact, conduction cooled superconducting radio-frequency cryomodule for particle accelerators. The cryomodule will accelerate an electron beam of average current up to 1 ampere in continuous wave (CW) mode or at high duty factor. The cryomodule consists of a single-cell superconducting radio-frequency cavity made of high-purity niobium, with an inner coating of Nb.sub.3Sn and an outer coating of pure copper. Conduction cooling is achieved by using multiple closed-cycle refrigerators. Power is fed into the cavity by two coaxial couplers. Damping of the high-order modes is achieved by a warm beam-pipe ferrite damper.

Vacuum electron devices and linear accelerators include a hollow cathode configured to emit a beam of electrons. An anode is configured to attach and focus the beam of electrons. A control grid is configured to control the beam of electrons emitted from the hollow cathode. A cylinder is positioned substantially coaxial with the hollow cathode and is configured to maintain a shape and trajectory of the emitted beam of electrons.

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 doses.

A linear accelerator head for use in a medical radiation therapy system can include a housing, an electron generator configured to emit electrons along a beam path, and a microwave generation assembly. The linear accelerator head may include a waveguide that is configured to contain a standing or travelling microwave. The waveguide can include a plurality of cells that are disposed adjacent one another, wherein each of the plurality of cells may define an aperture configured to receive electrons therethrough. The linear accelerator head can further include a converter and a primary collimator.

Embodiments of the disclosure provide a multi-ray-source accelerator and an inspection method. The multi-ray-source accelerator includes: a plurality of acceleration tubes, each acceleration tube of the plurality of acceleration tubes including an acceleration tube body that defines at least one cavity, the plurality of acceleration tubes being arranged in at least one row along a straight line or an arc and connected in series with each other; and a microwave unit configured to provide a microwave field to the plurality of acceleration tubes. The plurality of acceleration tubes are arranged to allow the microwave unit to provide the microwave field from an acceleration tube at one end of the plurality of acceleration tubes so as to accelerate electron beams in cavities of all the acceleration tubes.

Embodiments of the disclosure provide a multi-ray-source accelerator and an inspection method. The multi-ray-source accelerator includes: a plurality of acceleration tubes, each acceleration tube of the plurality of acceleration tubes including an acceleration tube body that defines at least one cavity, the plurality of acceleration tubes being arranged in at least one row along a straight line or an arc and connected in series with each other; and a microwave unit configured to provide a microwave field to the plurality of acceleration tubes. The plurality of acceleration tubes are arranged to allow the microwave unit to provide the microwave field from an acceleration tube at one end of the plurality of acceleration tubes so as to accelerate electron beams in cavities of all the acceleration tubes.

Technology is described for an electron gun driver including a half bridge driver circuit and a drive controller. The half bridge driver circuit includes a drive circuit configured to generate a grid drive voltage for a grid connection of an electron gun, and a cutoff circuit configured to generate a grid cutoff voltage for the grid connection of the electron gun, and a gate driver configured to switch between the grid drive voltage and the grid cutoff voltage. The drive controller is configured to generate a pulse input to the drive circuit and cutoff circuit and grid switching signals for the gate driver.