Abstract:
A charged particle beam irradiation apparatus includes: a scanning electromagnet that scans a charged particle beam; and a degrader that is provided on a downstream side of the scanning electromagnet in a scanning direction of the charged particle beam and adjusts a range of the charged particle beam by reducing energy of the charged particle beam. The degrader is configured to be closer to an upstream side in the scanning direction of the charged particle beam, outward in the scanning direction.
Abstract:
There is provided a particle beam therapy system that can rapidly change beam energy without increasing the size of a deflection electromagnet even in the case where the number of required beam-energy changes is large.There is provided a plurality of beam energy changing units each provided with a beam energy attenuation unit; a beam is deflected in such a way as to sequentially passes through the plurality of beam energy changing units; while a beam passes through one of the beam energy changing unit, the beam energy attenuation amount of another beam energy changing unit is changed.
Abstract:
Provided are an ion beam control apparatus and a control method for controlling an ion beam energy expansion level and an ion beam size in a radial direction. An ion beam control apparatus Sa is provided with an ion beam generating unit 2, and an ion beam control unit 1a in which a generated ion beam (IB) is input and controlled to be output with the prescribed level of energy expansion and the prescribed diameter in the radial direction. In the ion beam control unit 1a, phase rotation by a radio frequency electric field that increases existing probability with the prescribed level of energy is at least used.
Abstract:
A plurality of field emission device cathodes each generate emission of electrons, which are then controlled and focused using various electrodes to produce an electron beam. Horizontal and vertical deflection techniques, similar to those used within a cathode ray tube, operate to scan the individual electron beams onto portions of a phosphor screen in order to generate images. The use of the plurality of field emission cathodes provides for a flatter screen depth than possible with a typical cathode ray tube.
Abstract:
An electron-beam generator comprises an electron-emitting device and a modulating electrode capable of modulating an electron beam emitted from the electron-emitting device in response to an information signal. The modulating electrode and the electron-emitting device are laminated so as to interpose an insulating substrate therebetween.
Abstract:
An electron beam generating apparatus for an electron beam source having surface conduction electron emitting devices formed on a substrate; includes a measuring unit for measuring a device current flowing through each of the surface conduction electron emitting devices, an a device current storage unit for storing data measured by the measuring unit. In addition comparing unit compares latest data measured by the measuring unit with the data stored in the device current storage unit, a correction value storage unit stores a correction value for correcting a driving signal to be applied to each surface conduction electron emitting device, and an adjusting unit adjusts the correction value stored in the correction value storage unit.
Abstract:
An electron source is formed by at least one elementary electron emitter in which an emissive point having a very small radius of curvature operates on the field emission principle and produces an electron beam, the intensity of which is independent of any possible variations of electron emission. The emissive point cooperates with an extracting electrode, and a control electrode having a negative potential with respect to the extracting electrode is placed downstream of the extracting electrode with respect to the direction of propagation of the beam.
Abstract:
An emission current control system for balancing the individual emission currents from an array of hollow cathodes has current sensors for determining the current drawn by each cathode from a power supply. Each current sensor has an output signal which has a magnitude proportional to the current. The current sensor output signals are averaged, the average value so obtained being applied to a respective controller for controlling the flow of an ion source material through each cathode. Also applied to each controller are the respective sensor output signals for each cathode and a common reference signal. The flow of source material through each hollow cathode is thereby made proportional to the current drawn by that cathode, the average current drawn by all of the cathodes, and the reference signal. Thus, the emission current of each cathode is controlled such that each is made substantially equal to the emission current of each of the other cathodes. When utilized as a component of a multiple hollow cathode ion propulsion motor, the emission current control system of the invention provides for balancing the thrust of the motor about the thrust axis and also for preventing premature failure of a hollow cathode source due to operation above a maximum rated emission current.