Ion beam irradiation apparatus
First Claim
1. An ion beam irradiation apparatus comprising:
- a particle accelerator for developing an ion beam;
first deflection means disposed in the path of said ion beam, for deflecting said ion beam in a first direction perpendicular to the axis of the path of said ion beam;
second deflection means disposed in the path of said ion beam, for deflecting said ion beam in a second direction perpendicular to the axis of the path of said ion beam and perpendicular to said first direction in which the path of said ion beam is deflected by said first deflection means;
a first power supply for supplying a first exciting current having a first ac component and a first dc bias component to said first deflection means;
a second power supply for supplying a second exciting current having a second ac component and a second dc bias component to said second deflection means; and
control means for varying magnetic fields developed by said first and second deflection means in response to the amplitude and phase of said first and second ac components and the polarity and magnitude of said first and second dc bias components and thereby controlling the size and the direction scanned by said ion beam.
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Accused Products
Abstract
An ion-beam irradiation apparatus is provided which has x- and y-deflection magnets to wobble an ion beam for uniformly irradiating a field exceeding the beam diameter in size. An exciting current is supplied to the x- and y-deflection magnets independently, and the exciting current inlcudes both an ac component and a dc bias component. Suitable control of these components enables the irradiated field to be varied in shape and location. In particular, racetrack-shaped fields can be irradiated by adding dc components to triangular ac components. When used in cancer radio therapy, this apparatus enables the irradiated field to be moved quickly from one location to another, and to be matched with the shape of the tumor. Benefits of this apparatus include short treatment times and efficient use of the ion beam, so that substantially all of the ion beams may be delivered to the target.
124 Citations
8 Claims
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1. An ion beam irradiation apparatus comprising:
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a particle accelerator for developing an ion beam; first deflection means disposed in the path of said ion beam, for deflecting said ion beam in a first direction perpendicular to the axis of the path of said ion beam; second deflection means disposed in the path of said ion beam, for deflecting said ion beam in a second direction perpendicular to the axis of the path of said ion beam and perpendicular to said first direction in which the path of said ion beam is deflected by said first deflection means; a first power supply for supplying a first exciting current having a first ac component and a first dc bias component to said first deflection means; a second power supply for supplying a second exciting current having a second ac component and a second dc bias component to said second deflection means; and control means for varying magnetic fields developed by said first and second deflection means in response to the amplitude and phase of said first and second ac components and the polarity and magnitude of said first and second dc bias components and thereby controlling the size and the direction scanned by said ion beam. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for irradiating an ion beam, comprising the steps of:
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(a) developing an ion beam; (b) developing a first exciting current having a first ac component and a first dc bias component; (c) deflecting the path of said ion beam in a first direction perpendicular to the axis of the path of said ion beam in response to said step (b); (d) developing a second exciting current having a second ac component and a second dc bias component; (e) deflecting the path of said ion beam in a second direction perpendicular to the axis of the path of said ion beam and perpendicular to said first direction in which the path of said ion beam is deflected at said step (c) in response to said step (d); and (f) varying magnetic fields developed at said steps (c) and (e) for deflecting the path of said ion beam in response to the amplitude and phase of said first and second ac components and the polarity and magnitude of said first and second dc bias components and thereby controlling the size and the direction scanned by said ion beam.
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Specification