JPH0629884Y2 - Electron beam irradiation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This invention relates to an electron beam irradiation apparatus.

(Prior Art) In an electron beam irradiation device, a structure in which an electron beam from a cathode in a vacuum chamber is applied to an object to be irradiated which passes through the irradiation chamber is already well known.

The specific configuration will be described with reference to FIG. 2. Reference numeral 1 is a vacuum chamber, 2 is a cathode installed inside the chamber, and 3 is a cathode.
Is an irradiation chamber, 4 is an irradiation object, and 5 is a beam catcher. The object to be irradiated 4 is irradiated along the direction of the arrow by the irradiation chamber 3
Is transferred inside. Then, in the process of the transfer, the electron beam from the vacuum chamber 1 is applied.

In such a device, nitrogen gas is sprayed from the nitrogen gas spray nozzle 7 arranged around the irradiation window 6 of the vacuum chamber 1 so that the vicinity of the electron beam irradiation region in the irradiation chamber is as inactive as possible. Is blown toward the vicinity of the irradiation window 6 to replace the surrounding oxygen gas.

However, according to such a configuration, the sprayed nitrogen gas is heated by the electron beam, so that the gas temperature rises. In general, the object 4 to be irradiated has a low heat resistance temperature, so that it is necessary to prevent the gas temperature from rising, and therefore a large amount of nitrogen gas must be supplied.

Further, in the irradiation window portion 6, the inner surface of the holding frame 9 holding the window foil 8 is inclined toward the upper inside, so that the nitrogen gas heated as described above is applied to the window foil 8. Of the window foil 8 and the respective members in the vicinity of the window foil 8 are thermally deteriorated, and the life of the window foil 8 may be significantly shortened.

(Problems to be Solved by the Invention) This invention aims to reduce the supply amount of nitrogen gas supplied for replacement with oxygen gas and suppress the temperature rise of the window foil.

(Means for Solving the Problems) This invention has a structure in which nitrogen gas is blown toward the window foil or its vicinity from the inside of the holding frame of the window foil that constitutes the irradiation window of the vacuum chamber. Characterize.

(Embodiment) An embodiment of the present invention will be described with reference to FIG. In the figure, reference numeral 10 denotes a pipe brazed around the outer circumference of the holding frame 9, to which nitrogen gas is sent from the outside. A hole 11 is formed in the pipe 10, and this is a through hole 12 extending in a direction traversing the inside of the holding frame 9.
Is in communication with. The through hole 12 is open on the inner surface of the holding frame 9.

Reference numeral 13 denotes a crosspiece that supports the inner surface of the window foil 8 on the vacuum side.
This prevents the window foil 8 from being sucked and deformed toward the inside due to the vacuum inside the vacuum chamber 1, and also serves as a cooling fin.

When nitrogen gas is supplied from the pipe 10 to the through hole 12 through the hole 11 in the above configuration, the nitrogen gas is supplied to the window foil 8
It will be sprayed toward the atmosphere side surface, that is, near the lower surface. Oxygen gas in the vicinity of the lower surface of the window foil 8 or heated nitrogen gas is efficiently replaced with new nitrogen gas supplied by this spraying. Moreover, the spraying ensures that the window foil 8 and its vicinity are cooled.

In this invention, the pipe 10 is particularly installed on the outer circumference of the holding frame 9. If the pipe 10 is installed on the inner circumference of the holding frame 9, the inner circumference is within the electron beam irradiation area, so that the pipe installed on the inner circumference is irradiated with the electron beam, and thus the electron beam is irradiated. The loss of wire becomes large and the pipe becomes damaged.

If this point pipe 10 is installed on the outer circumference of the holding frame 9,
It is possible to avoid such electron beam loss and pipe damage.

(Effect of the Invention) As described in detail above, according to the present invention, the heating gas replacement in the vicinity of the irradiation window is facilitated as compared with the conventional configuration, and
There is an effect that the window foil can be surely cooled without any loss of electron beams or damage to the pipe for supplying nitrogen gas.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention, and FIG. 2 is an overall sectional view showing an embodiment of the present invention. 1 ... Vacuum chamber, 3 ... Irradiation chamber, 4 ... Irradiation object, 6 ... Irradiation window part, 8 ... Window foil, 9 ... Holding frame, 1
0 ... pipe, 12 ... through hole,

Claims (1)

[Scope of utility model registration request] 1. An electron beam irradiation apparatus comprising a vacuum chamber for emitting an electron beam and an irradiation chamber for irradiating an object to be irradiated with an electron beam from the vacuum chamber, wherein an irradiation window portion of the vacuum chamber is provided. A pipe through which nitrogen gas is sent is installed on the outer periphery of the holding frame of the window foil, a hole is provided in the pipe, and the hole is penetrated so as to cross the inside of the holding frame. An electron beam which is made to communicate with the hole so that the nitrogen gas from the hole of the pipe is blown toward the vicinity of the lower surface of the window foil through the through hole so that the through hole is opened on the inner surface of the holding frame. Irradiation device.