JPH03274499A - Irradiation device of charged particle beam - Google Patents

Abstract

PURPOSE:To enable sufficient irradiation of a beam to an object to be irradiated, without turning the object and also enable one single beam source for the purpose by constituting a device so as to distribute the beam to two beam paths by a switching electro-magnet and to deflect the beam to the object by deflecting electro-magnets. CONSTITUTION:An accelerator 1 accelerates charged particles to output a high energy beam and the beam is distributed to two beam paths by a switching electro-magnet 6. In other words, when a pulsating electric power source is connected to the electro-magnet 6, directions of exciting electric current can be switched thereby. In this way, the incident beam to deflecting electro-magnets 7 is discharged into different directions at every constant time interval. Each of the beam 8 is deflected by the electro-magnets 7 to get input to scanning electro-magnets 2. In this occasion, an amount of the deflection at the electro- magnets 7 is set so that the two beam 8 may have completely opposite incident directions concerning the incident directions of the beams 8. After that, each beam 8 incident on the electro-magnets 2 passes, after scanning, through a vacuum chamber 3 and irradiates an object to be irradiated, from both sides.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a charged particle beam irradiation device used for sterilization and the like.

[Conventional technology]

FIG. 3 is a configuration diagram showing a conventional charged particle beam irradiation device. In the figure, 1 is an accelerator that accelerates charged particles, and 2 is an accelerator that expands the irradiation range of the charged particle beam (hereinafter referred to as beam) after acceleration. A scanning electromagnet, 3 a vacuum chamber for causing the beam to travel in vacuum, 4 a vacuum window for taking out the beam from the vacuum chamber 3, and 5 an object to be irradiated. Next, the operation will be explained. The charged particles are accelerated by the accelerator 1 and become high-energy charged particles. The high-energy beam output from the accelerator 1 is scanned by the scanning electromagnet 2 so that it has a flat intensity distribution at the irradiated position '#J5. In addition, when the beam exits into the air, its energy decreases due to scattering, etc., so the beam is made to travel within the vacuum chamber 3 until close to the irradiated object 5 (and the beam travels close to the irradiated object 5). Nearby, the vacuum window 4 was taken out into the air,
The object to be irradiated 5 is irradiated. Generally, the absorption dose distribution of an electron beam, which is an example of a beam, in a substance is as shown in FIG. 4(A). Therefore, if the object 5 to be irradiated is inverted and beams are irradiated alternately from both directions, the absorbed dose distribution will become as shown in FIG. 4(B). In other words, the distribution becomes substantially uniform in the depth direction of the object 5 to be irradiated, and even a thick object 5 to be irradiated can be sufficiently irradiated with the beam.

[Problem to be solved by the invention]

Since the conventional charged particle beam irradiation device is configured as described above, 2. The object 5 to be irradiated can be irradiated with the beam from only one direction, and in order to irradiate a thick object 5, the object 5 to be irradiated must be reversed and the beam must be irradiated again. In order to sufficiently irradiate the object 5 with the beam, there were problems such as the need for a long time and the need to provide an extra mechanism.
As shown in Japanese Patent No. 600, there is one in which a beam source is provided on both sides of an object to be irradiated. This invention was made to solve the above-mentioned problems, and it is possible to sufficiently irradiate a beam onto an object to be irradiated without reversing the object, and to use a single beam source. The purpose is to obtain a charged particle beam irradiation device that can perform

[Means to solve the problem]

A charged particle beam irradiation device according to the present invention includes an accelerator that accelerates charged particles, a switching electromagnet that distributes a high-energy beam output from the accelerator into two paths, and a switching electromagnet that is provided on each of the two paths. , a deflecting electromagnet that deflects the beam in a direction opposite to the object to be irradiated, and a scanning electromagnet that widens the irradiation range of the beam so that each deflected beam hits the object to be irradiated.

[Effect]

The switching electromagnet in this invention distributes the accelerated beam in two directions, and the deflecting electromagnet deflects the two beams so as to irradiate the object from both sides, thereby uniformly irradiating the beam from both sides of the object.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 6 is a switching electromagnet that distributes the beam output from the accelerator 1 into two paths, 7 is a deflection electromagnet that deflects each of the two beams 8, and the other parts are given the same symbols. This is equivalent to the one shown in FIG. Next, the operation will be explained. The accelerator 1 accelerates charged particles and outputs a high-energy beam. This beam is split into two paths by a switching electromagnet 6. The switching electromagnet 6 used is
A direct current electromagnet may be used, and by switching the direction of excitation current at regular intervals, the input beam can be made into beams 8 in two directions. For example, if a pulse power source (not shown) that generates a pulsed current as shown in FIG. 2 is connected to the switching electromagnet, the direction of the excitation current can be switched. In this way, the beam incident on the bending electromagnet 7 is emitted in different directions at regular intervals. These beams 8 are
Each is deflected by a deflecting electromagnet 7 and input to the scanning electromagnet 2. Here, the amount of deflection in the deflecting electromagnet 7 is set so that the two beams 8 are incident on the object 5 facing each other with respect to the incident direction of the beam 8 . Each beam 8 input to the scanning electromagnet 2 is scanned in the same manner as in the conventional case, and then passes through the vacuum chamber 3 and is irradiated onto the object 5 from both sides.

【Effect of the invention】

As described above, according to the present invention, the charged particle beam irradiation device distributes the beam into two paths using a switching electromagnet,
Since the beam is deflected away from the irradiated object using a deflection electromagnet, it is possible to irradiate the irradiated object with the beam from the image side using a single beam source, and the irradiated object can be reversed. It has the effect of getting something you don't need.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing a charged particle beam irradiation device according to an embodiment of the present invention, Fig. 2 is a waveform diagram showing an example of a pulse waveform supplied to a switching electromagnet, and Fig. 3 is a conventional charged particle beam irradiation device. FIG. 4 is a configuration diagram showing the apparatus, and a distribution diagram showing the absorption dose distribution of the electron beam in the irradiated object. 1 is an accelerator, 2 is a scanning electromagnet, 5 is an irradiated object, 6 is a switch notching electromagnet, and 7 is a deflection electromagnet. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] an accelerator that accelerates charged particles; a switching electromagnet that distributes the charged particle beam output from the accelerator into two paths; and a switching electromagnet provided on each of the two paths,
a deflecting electromagnet that deflects the charged particle beam in a direction opposite to the object to be irradiated; and a deflecting electromagnet that expands the irradiation range of the deflected charged particle beam and irradiates the expanded charged particle beam toward the object to be irradiated. A charged particle beam irradiation device equipped with a scanning electromagnet.