JPH0530800U - Electron beam irradiation device - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to prevent the secondary window foil, which protects the primary window foil of the irradiation window, from fluttering and being damaged by cooling air. [Structure] A pressing member is provided on the inner surface of the secondary window foil to bend the secondary window foil in a state where tension is applied toward the outside. Since the secondary window foil is pressed down by this pressing member, it is prevented from fluttering due to the supply and discharge of cooling air.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electron beam irradiation device.

[0002]

[Prior Art]

 It is well known that the irradiation window provided on the end surface of the scanning tube in the electron beam irradiation device is sealed by a window foil made of a metal thin film, and the electron beam is irradiated to the irradiation object through this window foil. .. In this case, the temperature of the window foil rises as the electron beam passes through it, so a cooling gas is sprayed to cool it.

On the other hand, when the irradiated object is a powder, for example, the powder may be blown off by the cooling gas that cools the window foil. In order to avoid this, a gap between the window foil and the irradiated object may be avoided. Separately, a window foil made of a metal thin film (hereinafter, this window foil is referred to as a secondary window foil, and the window foil provided on the irradiation window described above is referred to as a primary window foil) is provided, and the primary window foil is powdered. Protects against sticking.

In this case, since the electron beam also passes through the secondary window foil, it is necessary to cool this secondary window foil. FIG. 3 shows the conventional configuration. In the figure, 1 is a scanning tube, 2 is an irradiation window, and 3 is a primary window foil thereof, which is attached to an end surface of the scanning tube 1 by a flange 4. A secondary window foil 5 is attached to the flange 4 by a holding frame 6.

Reference numeral 7 is a duct for sending cooling gas, for example, cooling air, and 8 is an exhaust duct. The cooling air sent from the duct 7 is sent along the outer surface of the primary window foil 3, and the flange 4 The feeding direction is reversed by this and the gas is exhausted to the exhaust duct 8 along the inner surface of the secondary window foil 5. In this process, both window foils 3 and 5 are cooled. The arrows indicate the flow of cooling air.

By the way, in such a structure, since the inner surface of the scanning tube 1 is evacuated, the primary window foil 3 curves toward the inside of the scanning tube 1 as shown in the figure. The secondary window foil 5 is always flat, but when cooling air is sent to both window foils 3 and 5 as described above, the wind pressure causes the air to flow in the opposite direction to the primary window foil 5 as shown in the figure. To bend. Therefore, the cooling air is repeatedly sent and exhausted, and the secondary window foil 5 flaps and bends.

When such bending and stretching are repeated, the supporting portion of the secondary window foil 5 is loosened and the pressing force becomes insufficient. In addition, the secondary window foil 5 may be damaged by metal fatigue.

[0008]

[Problems to be solved by the device]

 An object of the present invention is to prevent the secondary window foil, which protects the primary window foil, from flexing and stretching due to the supply and discharge of cooling air, thereby loosening its supporting portion or damaging it due to metal fatigue.

[0009]

[Means for Solving the Problems]

 The present invention is characterized in that an inner surface of the secondary window foil is provided with a pressing member that presses the secondary window foil so that the secondary window foil is curved in an outward direction on the opposite side to the primary window foil.

[0010]

[Action]

 The secondary window foil is always curved outward by the pressing member. Therefore, the secondary window foil is always tensioned, so even if the cooling air is sent and exhausted, it will not bend or stretch significantly due to the wind pressure. As a result, the loosening of the supporting portion of the secondary window foil or the occurrence of damage due to metal fatigue can be avoided.

[0011]

Embodiment An embodiment of the present invention will be described with reference to FIG. It is to be noted that the parts denoted by the same reference numerals as in FIG. 3 indicate the same or corresponding parts. According to the present invention, a holding member 9 is provided on the inner surface of the secondary window foil 5 so as to bend the secondary window foil 5 in the outward direction on the opposite side of the primary window foil 3.

Specifically, both ends of the secondary window foil 5 are supported by the holding metal fitting 10 and the flange 11, both ends of the pressing member 9 are attached to the flange 11, and the packing 12 is provided between the flanges 4 and 11. Be intervened. FIG. 2 is a perspective view of the attached state.

The cooling air circulates in the same manner as in FIG. 3, and in the process, both window foils 3, 5 are cooled by the cooling air. On the other hand, the secondary window foil 5 is given a tension toward the outside by the pressing member 9 and is constantly pressed so as to be curved. Therefore, even if the cooling air is repeatedly sent and exhausted, the secondary window foil 5 does not flutter and is not greatly curved.

The pressing member 9 is preferably elastic. When the secondary window foil 9 is elastic, even if the secondary window foil 9 bends or stretches, the pressing member 9 responds to the elasticity in response to the bending and stretching so that the secondary window foil 5 and the pressing member 9 always contact each other. become. Therefore, the flapping of the secondary window foil 5 will be further eliminated.

[0015]

[Effect of the device]

 As described above, according to the present invention, since the secondary window foil is curved so as to give tension by the pressing member, it is possible to prevent the supporting portion of the secondary window foil from being loosened and damaged due to bending and stretching of the secondary window foil. There is an effect that can be done.

[Brief description of drawings]

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

FIG. 2 is a perspective view of a portion of FIG.

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols]

 1 Scanning Tube 2 Irradiation Window 3 Primary Window Foil 5 Secondary Window Foil 7 Duct for Air Supply of Cooling Air 8 Duct for Exhaust of Cooling Air 9 Holding Member

Claims (1)

[Scope of utility model registration request] 1. A secondary window foil for protecting a primary window foil for sealing an irradiation window provided on an end face of a scanning tube is arranged facing the outside of the primary window foil, and an electron beam is applied to the primary window. While irradiating the irradiated object through the foil and the secondary window foil, in the electron beam irradiation device formed by cooling the primary window foil and the secondary window foil by a cooling gas, the secondary surface on the inner surface, the secondary An electron beam irradiation apparatus provided with a pressing member for bending a window foil outward while applying tension.