Abstract:
Embodiments include methods and systems to perform computed tomography. Respiratory signal data and imaging data associated with a heart can be received, and a target area of the heart can be determined responsive to the imaging data. An initial energy and a direction of a proton beam to deliver a Bragg peak of the proton beam to the target area can be determined. The initial energy and the direction of the proton beam then can be modified responsive to the respiratory signal data to generate a modified initial energy and a modified direction. A proton computed tomography controller can be instructed to deliver the proton beam to the heart at the modified initial energy and the modified direction.
Abstract:
One embodiment relates to an electron beam apparatus which includes a dual-lens electron gun for emitting an electron beam. The electron beam is a high beam-current electron beam in a first operating mode and a low beam-current electron beam in a second operating mode. The apparatus further includes a column aperture which is out of the path of the high beam-current electron beam in the first operating mode and is centered about an optical axis of the electron beam apparatus in the second operating mode. Another embodiment relates to an electron gun which includes a first gun lens, a beam limiting aperture, and a second gun lens. The first gun lens focuses the electrons before they pass through the beam-limiting aperture while the second gun lens focuses the electrons after they pass through the beam-limiting aperture. Other embodiments, aspects and features are also disclosed.
Abstract:
An electron beam sterilizing device, comprises: an electron- generating filament; a beam-shaper; an output window; a high-voltage supply, capable of creating a high-voltage potential between the electron-generating filament and the output window, for acceleration of electrons; a high-voltage supply for driving current through the electron-generating filament; a control unit for controlling the operation of the electron beam sterilizing device. The device is characterized in that the electron beam sterilizing device has at least three operational states: - an OFF-state, where there is no drive current through the electron-generating filament, - an ON-state, where the electron-generating filament is kept at a temperature above the emission temperature so as to generate electrons for sterilization, and - a standby state, between the OFF-state and ON-state, where the electron- generating filament is kept at a predetermined temperature just below the emission temperature, wherein the control unit is able to control the device to assume the standby state.
Abstract:
A multi-gap inductor core includes magnetic lamination sheets made of magnetic core material arranged in a stack, and fixing layers made of a fixing material. Each fixing layer is arranged between a corresponding pair of adjacent magnetic lamination sheets. Each fixing layer also includes an embedded mechanical spacer that defines a gap having a predetermined thickness between a corresponding pair of adjacent magnetic lamination sheets.
Abstract:
There is disclosed a method of controlling an electron gun without causing decreases in brightness of the electron beam if a current-limiting aperture cannot be used. The electron gun (10) has a cathode (11), a Wehnelt electrode (12), a control electrode (13), an anode (14), and a controller (22). The Wehnelt electrode (12) has a first opening (12c) in which the tip of the cathode is inserted, and focuses thermal electrons emitted from the tip of the cathode (11). The thermal electrons emitted from the tip of the cathode (11) are caused to pass into a second opening (13c) by the control electrode (13). The anode (14) accelerates the thermal electrons emitted from the cathode (11) such that the thermal electrons passed through the second opening (13c) pass through a third opening (14b) and impinge as an electron beam (B1) on a powdered sample (8). The controller (22) sets the bias voltage and the control voltage based on combination conditions of the bias voltage and control voltage to maintain the brightness of the beam constant.
Abstract:
An electron beam sterilizing device, comprises: an electron-generating filament; a beam-shaper; an output window; a high-voltage supply, capable of creating a high-voltage potential between the electron-generating filament and the output window, for acceleration of electrons; a high-voltage supply for driving current through the electron-generating filament; a control unit for controlling the operation of the electron beam sterilizing device. The electron beam sterilizing device has at least three operational states which include: an OFF-state, where there is no drive current through the electron-generating filament; an ON-state, where the electron-generating filament is kept at a temperature above the emission temperature so as to generate electrons for sterilization; and a standby state, between the OFF-state and ON-state, where the electron-generating filament is kept at a predetermined temperature just below the emission temperature. The control unit controls the device to assume the standby state.
Abstract:
An optoelectronic modulator is based on the concentration of an electron beam from an electron gun by a tapered cavity, which sides are photosensitive and change the electrical conductivity under the illumination of light (electromagnetic radiation). The light modulation causes the corresponding changes in the current transported across the walls of the cavity. The remaining part of the electron current exits the cavity aperture and forms an amplitude-modulated divergent electron beam.