JPS6089053A - Ion pump - Google Patents

Abstract

PURPOSE:To increase the performance and reduce the cost of an ion pump by constituting it by installing a positive unit made of Al in an Al-Mg alloy casing also serving as a negative electrode with an insulating space interposed. CONSTITUTION:Plural positive Al plates 2 each having many holes 3 are placed parallel to each other through conductive metallic joints 4 to make a positive unit 12. Next, the positive unit 12 is placed in a box-like rectangular parallelepiped casing 1 also serving as a negative electrode with an insulating spacer 6 interposed. Then the thus obtained member, a magnet 10 and a heater 11 are attached inside a cover 14. After that the openings of the casings of thus obtained bodies are welded to the two openings of a cylindrical body 9, thereby constituting an ion pump. By thus using an Al-Mg alloy to make the negative electrode instead of using a Ti steel, it is possible to reduce the cost and improve the assembly efficiency of the ion pump.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ion pump configured to use the casing itself of the ion pump as a cathode.

Conventionally, as shown in FIG. 1 and FIG. 2, as an ion pump, a plurality of OAN plate anodes 2 each having a large number of through holes 6 are arranged in parallel at intervals, and conductive connecting fittings 4 are arranged in parallel. An anode unit consisting of a combination of a plurality of anodes 2 connected through a pair of through holes '1?' i An insulating spacer 6 is placed between the steel plate cathodes 5.
A casing 8, in which the electrode unit 7 consisting of the anode 2 and the cathode 5 is housed and fixed, is fixed to the tube body 9.
The magnets 10 are fitted into openings provided on both sides of the casing 8 in the diametrical direction and fixed by welding, and the magnets 10 are fixed to the outer surfaces of both side plates and the end plate of the casing 8. 11, a high voltage is applied to the anode and cathode, and a self-exhaust operation is performed by the adsorption effect of the active T1 atoms generated by snowing the Ti steel and the gas molecules in the casing. There are known devices configured to allow

However, in the case of the conventional ion pump, extremely expensive Ti steel is used as the cathode 5, and the cathode 5 and the casing 8 are provided independently, so the structure is complicated and the weight is high. It is heavy and expensive. In addition, when operating the ion pump, it is preferable to heat the Ti steel to a high temperature of 450°C or higher in order to perform degassing including activation treatment, but when the anode 2 is made of AA, The anode cannot withstand the high temperatures mentioned above, so if the anode is made of AM and the cathode is made of Ti steel, it is inevitable that the treatment temperature of 150°C, which is the AQ processing temperature, will be applied.
Therefore, in terms of performance, there were problems in degassing and activating Ti steel. In addition, since the anode 2 is used while being sandwiched and bonded to the cathode 5, when the ion pump is heated, the electrodes may be deformed due to the difference in thermal expansion coefficient between the AN anode 2 and the Ti steel cathode 5. There was a problem.

Therefore, the inventor conducted an experiment using an Al-MP gold alloy and an AH-MY-St gold alloy as a cathode, and found that the performance was equivalent to that of using a conventional cathode made of Ti steel. After discovering this, they focused on the fact that the structure could be simplified by using both the cathode and the casing, and completed this invention.

This invention provides a cathode/casing 1 made of M-Mf gold alloy.
The gist of this is an ion pump characterized in that M anodes 2 are accommodated within the ion pump via an insulating space.

Next, the present invention will be explained in detail using illustrated examples.

6 to 5 show an embodiment of the present invention, in which a plurality of M plate anodes 2 each having a large number of through holes 3 are arranged in parallel at intervals. An anode unit 12 is constructed by connecting via a conductive connecting fitting 4, and an insulating strip 4-6 made of an electrically insulating material such as ceramic is provided on the surface of the anode 2 at the end of the anode unit 12.
A rectangular box-shaped cathode and casing 1 made of an Ae-w alloy, which is a metal with a catalytic action, is fixed.
The anode unit 12 is housed inside the insulating spacer 6.
Rectangular openings are provided on both diametrical sides of the tubular body 9, which is fixed via a connecting flanges 13 at its ends, and each opening has a rectangular open end in the cathode/casing 1. They are fitted and fixed by welding.

Magnets 10 are fixed to the outer surfaces of both side plates and the outer surface of the end plate of the cathode/casing 1, a heater 11 is housed in a groove provided in the cathode/casing 1, and each magnet 10 is covered with a cover 14. Further, each of the anode units 12 is electrically connected, and a high voltage is applied between the anode unit 12 and the cathode/casing 1. In the figure, 15 is a high-voltage electric wire connected to the anode 2.

As a result of conducting experiments on the ion pump configured in this manner, it was confirmed that the ion pump exhibited performance equal to or higher than that of conventional ion pumps at a heating temperature of 150° C. or less. Also 5
According to the experimental results with a 00 A/s ion pump,
Bake at 150℃ for 24 hours.

It was confirmed that a performance of 10-10 Torr could be easily obtained at 5 KV, and that ion pump currents up to 10-10 Torr could be stably measured.

Furthermore, heating could be uniformly performed by the heater 11 installed in the cathode/casing 1.

When carrying out this invention, the AQ-Mf gold alloy having a getter function constituting the cathode and casing is MPo
For example, JIS, [(4000
A3005, A3052, A3154, shown in
A3083. A3086 etc. can be used. =
Moreover, AA-Mf- which added St in addition to Mf to AQ
8i alloy e.g. A610 shown in JIS, H4000
1 may be used. Furthermore, the cathode and casing 1
To manufacture a cathode casing, for example, extrude a cathode casing component with a groove-shaped cross section as shown in Figure 6, cut it to an appropriate length, and then fix an end plate to the groove end by welding. .

According to this invention, instead of using expensive Ti steel as the material of the cathode as in the past, relatively inexpensive AU-M
Since we use W alloy and the cathode and casing are not separate, but instead serve as both, the structure is simpler and lighter than conventional ion pumps, and it can be manufactured at a lower cost. Furthermore, compared to a cathode made of Ti steel, Alt-M? In the case of a cathode made of an alloy, the ionic current is stable, and the material of the anode is 1, and the material of the cathode and casing is also AQ type,
Since both have substantially the same coefficient of thermal expansion, effects such as being able to prevent deformation of the electrode during heat treatment can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional plan view of a conventional ion pump in which a cathode and a casing are independent, and FIG. 2 is a perspective view of an electrode unit in the ion pump. 6 to 5 show an embodiment of the present invention, in which FIG. 6 is a cross-sectional plan view of the ion pump, FIG. 4 is a side view of the ion pump, and FIG. 5 is a perspective view of the anode unit. It is a diagram. In the figure, 1 is a cathode and casing made of AIt-MP alloy, 2 is an Affi anode, 6 is a through hole, 4 is a conductive connection fitting, 6 is an insulating spacer, 9 is a tube body, 10 is a magnet, 11 is a heater, 12 is an anode unit. −7−′

Claims (1)

[Claims] Aff is placed inside the cathode and casing 1 made of An-MY alloy.
An ion pump characterized in that an anode 2 of i is accommodated through an insulating space.