JPH0592998U - X-ray irradiation device - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to prevent vacuum leaks in the accelerating tube due to rebounding electrons from the metal plate. [Structure] In a structure in which a window foil provided on an accelerating tube is held by a window holding frame, a cooling panel is provided on a lower surface of the window holding frame to shield electrons rebounding from a metal plate. Bounced electrons are blocked by the cooling panel from heading towards the window restraint. As a result, local overheating of the window restraint frame is prevented and expansion of the metal seal is avoided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an X-ray irradiation device using an electron beam.

[0002]

[Prior Art]

 An X-ray irradiator using an electron beam takes out electrons accelerated by an accelerating tube to the atmosphere side through a thin window foil attached to a scanning tube, irradiates this on a metal plate to generate X-rays, and The object is irradiated with a line.

In the X-ray irradiation device having such a structure, when the electrons hit the metal plate, the rebounded electrons from the electrons may directly hit the window holding frame holding the window foil. As a result, the window restraint frame is locally overheated, and the metal seal that seals the window foil causes thermal expansion, which may result in vacuum leakage.

[0004]

[Problems to be solved by the device]

 The purpose of this study is to avoid vacuum leakage due to rebounding electrons from a metal plate.

[0005]

[Means for Solving the Problems]

 The present invention is characterized in that a cooling panel for shielding rebounding electrons is provided on the lower surface of the window holding frame which holds down the window foil.

[0006]

[Action]

 Even if the bounced electrons from the metal plate go to the window holding frame, the bounced electrons hit the cooling panel before hitting the window holding frame, which prevents the bounce electrons from hitting the window holding frame. Therefore, the window restraint frame will not be locally overheated by rebounding electrons, and vacuum leakage due to expansion of the metal seal will not occur. Although the temperature of the cooling panel tends to rise due to the rebounding electrons colliding with it, the temperature rise is suppressed by the cooling action of the cooling panel.

[0007]

【Example】

 An embodiment of the present invention will be described with reference to FIG. Reference numeral 1 is a scanning tube having a high vacuum inside, 2 is an irradiation window, 3 is a window foil thereof, and both sides of the scanning tube 1 are provided with a flange 4 of the scanning tube 1 and a window restraining frame 5 with a metal seal 6 interposed therebetween. It is attached to the end face of.

The electrons 7 are extracted to the atmosphere side through the window foil 3 of the scanning tube 2 and irradiate a gold wing plate (for example, tantalum) 8. As a result, X-rays 9 are generated from the metal plate 8. The X-ray 9 irradiates the irradiated body 10.

These configurations are not particularly different from the conventional ones, and when electrons hit the metal plate 8, some of the electrons look back and become the bounce-back electrons 11, as described above. Is.

According to the present invention, a cooling panel 12 is provided on the lower surface of the window restraining frame 5 to shield the look-back electrons 11 toward the window restraining frame 5. The cooling panel 12 is arranged so as to cover the lower surface of the window holding frame 5, and has therein a flow passage 13 through which a cooling medium such as cooling water always flows.

In such a configuration, even if the bounce-back electrons 11 are directed from the metal plate 8 toward the window holding frame 5, the bounce-back electrons 11 hit the cooling panel 12 before hitting the window holding frame 5, As a result, the rebounding electrons 11 do not hit the window holding frame 5. Therefore, the window restraining frame 5 is not locally overheated by the look-back electron 11, and vacuum leakage due to the expansion of the metal seal 6 does not occur.

On the other hand, the temperature of the cooling panel 12 tends to rise due to the collision of the rebounding electrons 11 with the cooling panel 12. However, since the cooling panel 12 is cooled by the cooling medium constantly flowing in the flow passage 13 inside the cooling panel 12, the cooling panel 12 is cooled. , Its temperature rise is suppressed within a certain range.

[0013]

[Effect of the device]

 As described above, according to the present invention, when the accelerated electrons are applied to the metal plate through the window foil to generate X-rays, the rebounding electrons collide with the window holding frame holding the window foil to cause the metal to move. The fact that the seal expands and causes a vacuum leak has the effect of reliably preventing it.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols] 1 Scan tube 2 Irradiation window 3 Window foil 5 Window restraining frame 6 Metal seal 7 Electron 8 Metal plate 9 X-ray 10 Irradiated object 11 Bounced electron 12 Cooling panel

Claims (1)

[Scope of utility model registration request] 1. The accelerated electrons are taken out to the atmosphere side through a window foil attached to an irradiation window of a scanning tube, the metal plate is irradiated with the electrons to generate X-rays, and the X-rays are irradiated to an object to be irradiated. In an X-ray irradiating device adapted to irradiate, an X-ray which is provided with a cooling panel for shielding rebound electrons from the metal plate on a lower surface of a window holding frame holding the window foil with a metal seal. Irradiation device.