JPS63145678A - Radiation remedy apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electron beam deflection device for a high-energy radiation therapy device.

[Conventional technology]

FIG. 2 is a configuration diagram of an electron beam deflection device of a conventional radiation therapy apparatus. In the figure, (1) is the electron gun, (2) is the electron beam emitted from the electron gun (11), (3) is the electron beam (2) emitted from the electron gun il+ and the accelerating tube, and (4) is the accelerating tube. Pipe (3
A waveguide that supplies microwave power to 1, (51 is an electron beam accelerated in an accelerating tube (2) a beam duct that guides to a deflection magnet (6), (61 is a deflection magnet, <<7>> is an electron beam ( 2)
This is the X-ray (8) generated by the 181 X-ray target, which converts X@ into X@. (91 flattening film, concave monitor checker, αυ collimator.

Next, the operation will be explained. The electron beam (2} exiting the electron gun 111 is guided to an acceleration tube (3) and accelerated to high energy by the electric field of the microwave supplied to the acceleration tube (3).

The electron beam (21) accelerated to high energy passes through the vacuum beam duct {5} kept in a high vacuum, is deflected by the deflection magnet (6), and collides with the X-ray target (7) to generate X-rays. .This X-ray (8) has a strong distribution in the front direction, and is flattened to make it uniform in intensity distribution. .

[Problem that the invention seeks to solve]

Since the conventional radiation therapy apparatus is configured as described above, there is a large leakage magnetic field along the electron beam trajectory of the deflection magnet that deflects the high-energy electron beam (2).
There were problems such as the exit and the trajectory inside the magnet deviated from the geometric optical conditions, making it difficult to successfully guide the electron beam onto the X-ray target and freely change the focusing conditions.

This invention was made to solve the above-mentioned problems, and it is possible to bring the trajectory of an electron beam deflected by a deflecting magnet closer to geometrical optical conditions, and at the same time, it is possible to reduce the rotation edge of the entrance and exit of the deflecting magnet and the magnetic field. The object of the present invention is to obtain a device that can freely change the focus of an electron beam on an X-ray target by rotating a rotating edge attached to a clamp.

[Means for solving problems]

The radiation therapy device according to the present invention has a rotating magnetic clamp attached to the entrance and exit of the deflection magnet, so that leakage magnetic flux from the deflection magnet is bypassed through the magnetic clamp, and no extra magnetic field is generated in the trajectory of the electron beam. be. Furthermore, by rotating the rotating edge of the magnetic clamp and the rotating edge of the deflecting magnet, the focus of the electron beam on the X-ray target can be changed freely.

[Effect]

The rotating edge according to this invention is attached to both the magnetic clamp and the deflection magnet, and by rotating the semicircular rotating edge, the edge of the magnet's magnetic field relative to the electron beam can be freely changed other than perpendicularly, and due to the edge effect. Focusing and divergence of the electron beam can be facilitated.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the same reference numerals as in FIG. 2 indicate the same or equivalent parts. Figure 3 shows the deflection unit that deflects the electron beam by 270', and Figure 47J4 shows the aberration-free deflection magnet (1
4 is a diagram explaining the relationship between 13 and an electron beam (2). (12a) and (12b) are aberration-free deflection magnets, αJ is a magnetic clastic, and α is an aberration-free deflection magnet (1ki). This is a rotating edge attached to the entrance and exit of (121-+) and the magnetic club α4.Next, the operation will be explained.By rotating this rotating edge a3, the boundary conditions of the magnetic field with respect to the electron beam trajectory can be changed. By changing these conditions, the electron beam (21) after passing through the deflection magnet α becomes either convergent or divergent, and the size of the electron beam above the X-ray target (71) can be freely changed.

The electron beam (21) that enters the incident side of the aberration-free deflection magnet 2 is focused by the electron beam (21) when the rotation angle β1 of the rotating edge α is + (rotation position in FIG. 2) is narrowed down.Similarly, when the aberration-free deflection magnet (1) exits, the rotating edge (41) has a focusing effect when the rotation angle I2 is + (rotation position in Figure 3), so the electrons as a whole are The beam (21) receives a strong focusing effect. Conversely, if βl and β2 are negative, the electron beam (21 receives a divergent force)
After passing through the beam, the electron beam receives a large divergent force and spreads out.

Although the above embodiment uses a two-pole achromatic electromagnet, it does not necessarily have to be used only for a two-pole achromatic electromagnet.

FIG. 5 shows the one used in a one-volume electromagnet. In the figure, C1!19 is the rotating edge (14k) on the bending electromagnet side)
.

(14d) and magnetic clamp side rotating edge (14a),
This is a rotating edge fixing plate for fixing (14c). (16a) and (16b) are rotary edge drive gears that transmit rotational force to the four rotary edges fixed by this rotary edge fixing plate. η is the motor that rotates the rotary edge drive gear; 4 is the support that fixes the motor and electromagnet to the yoke; 4 is the coil that excites the electromagnet; (21J is the through hole in the clamp where the vacuum chamber, etc. for passing the beam is inserted). be.

FIG. 6 is a diagram illustrating the rotation of this rotating club.

The rotating edge on the magnet side (141)), the rotating edge on the magnetic clamp side (14a), and the rotating edge fixing plate (when combined into one stage, the whole becomes a cylinder, and one end of the rotating edge on the magnetic clamp side (14a) A semicircular gear (16a) is attached to the holder, and by rotating this gear, the entire rotating edge rotates.

〔Effect of the invention〕

As described above, according to the present invention, since the deflection system of the high-energy radiation therapy device is provided with a magnetic clamp and a rotating edge, the spot size of the electron beam on the X-ray target or scatterer can be changed freely. , has a great effect on expanding the therapeutic focus of radiation therapy.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the configuration of a radiation therapy apparatus according to the present invention, FIG. 2 is a diagram illustrating the configuration of a conventional apparatus, and FIG. 3 is a diagram illustrating the configuration of the 270@deflection unit according to the apparatus of the present invention. ,
FIG. 4 is a diagram illustrating deflection control of an electron beam, FIG. 5 is a diagram illustrating another example of the configuration of an aberrationless electromagnet, and FIG. 6 is a diagram illustrating a rotating clamp section. (2)...Electron beam, α ri...Aberration-free deflection magnet, (1
3)...Magnetic club, (14...Rotating edge) In addition, the same reference numerals in the drawings indicate the same or equivalent parts.

Claims (2)

[Claims] (1) In a high-energy radiation therapy device, a magnetic clamp with a rotating edge is attached to the deflection magnet that deflects the electron beam along the trajectory of the electron beam, on the entrance or exit side of the deflection magnet, or on both the entrance and exit sides. A radiation therapy apparatus characterized in that a gap is provided between the magnetic clamp and the deflection magnet, and by changing the gap, the trajectory of the electron beam can be corrected and the focusing of the electron beam can be changed at the same time. (2) A fixed plate of non-magnetic material is inserted in the gap between the rotating edge on the deflecting magnet side and the rotating edge on the magnetic clamp side to maintain parallelism, so that the rotating edges on both sides can rotate simultaneously and while remaining parallel. A radiation treatment device characterized by: