JPS5830056A - Pillar-formed electrode of quadruple pole mass analyzer - Google Patents

Abstract

PURPOSE:To enhance the surface accuracy of a pillar-formed electrode and manufacture it light in weight and at a low cost by processing four electrode bars into V-shaped profile, made from an electroconductive material, which tolerates subjection for an extrusion or drawout process, and by coating that surface of electrode bars whose cross-section presents a hyperbola, with an anti- corrosive metal material. CONSTITUTION:Pillar-formed telepoles are manufactured in four pieces at one time from a single material specialized for drawing, so that error between telepoles is small. As material is used light-metal such as aluminum to assure lightweight compared with a conventional one made of stainless steel besides, removal of unnecessary parts, which can be easily obtained through designing of the dies in optimum form, can give a still lighter construction. The hyperbola in cross-section can be provided easily with high precision by using an accurately processed dies. Surfaces of these aluminum electrodes are coated with a metal highly resistant against corrosion such as gold because they are likely to corrode owing to ion collision etc. or to be roughed by gases emitted from the inside of the aluminum material under vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in columnar electrodes for quadrupole mass spectrometers.

FIG. 1 is a perspective view of a conventional columnar electrode. Four electrode rods 1a, 1 whose opposing surfaces are formed to have a hyperboloid cross section
b, lc and 1d form one columnar electrode 1. When ions 2 are sent into the center of this columnar electrode 1 in the direction of the arrow as shown by the broken line, only ions having masses within a specific range can be taken out from the other end.

The position and direction of sending the ions 2 is the center of the quadruple column of the columnar electrode 1, and the distance from the electrodes is the same (r, where X is the direction of electrode 1a, IC direction is X, and electrode 1b is the same distance from the electrodes.

When the direction of 1d is y, the ions 2 are sent in two directions perpendicular to these directions. Also.

A voltage of U-1-VoCopωt is applied between the electrodes 1a and 1c, and a voltage of -(U+V,
A voltage called Cosωt) is applied. That is.

Constant voltage U and r f (radio frequency
y) The sum of voltages V and Cosωt is applied.

In conventional columnar electrodes configured in this manner, the electrode surfaces were manufactured by machining because it helps to improve resolution if the opposing surfaces have the same shape. Therefore, manufacturing errors between the four pillars are likely to occur, and the resolution thereof is reduced. In addition, the material of the electrode is molybdenum or stainless steel, which is relatively heavy, making the device heavy.Furthermore, it is difficult to precisely machine the cross section of the electrode into a hyperbolic shape.

The present invention aims to provide a columnar electrode for a quadrupole mass spectrometer that is lightweight and inexpensive, with hyperboloid precision of the electrode surface. The method consists of processing a conductive material that can be processed into a V-shaped cross section, and coating the surface of the electrode rod with a hyperbolic cross section with a corrosion-resistant metal material.

FIG. 2 is a perspective view of a columnar utility pole that is an embodiment of the present invention. The electrodes in this case are assembled by extruding or drawing a conductive material such as aluminum and cutting it into equal lengths. Additionally, a corrosion-resistant metal material such as gold may be deposited on the surface of the utility pole to increase its conductivity. Note that the arrangement of each utility pole surface is the same as in the case of FIG.

In the pole-shaped utility pole constructed in this way, since four utility poles are made using one drawn material, manufacturing errors between each utility pole are small. Furthermore, since a light metal such as aluminum is used, it is lighter than conventional stainless steel ones, and unnecessary parts can be easily removed due to the shape of the die, making it even lighter. In addition.

The hyperbolic cross section has the advantage that many high-precision pieces can be easily obtained if the shape of the die is precisely processed.

The surface of aluminum electrodes may be corroded by ion bombardment, etc., or the surface may become rough when gas is released from inside the aluminum material in vacuum, so the surface may be coated with a corrosion-resistant metal such as gold. It is.

Therefore, it can be operated suitably for a long period of time.

The columnar electrode of this example is constructed by fabricating the electrode by processing a conductive material that can be extruded or drawn using a die with a hyperbolic cross section, and then coating the surface with gold or the like and assembling it. This has the advantage of being accurate, lightweight, and inexpensive.

In the above embodiment, it has been explained that the lengths of the utility poles are equal, but the lengths may be different for convenience of holding the electrodes. Furthermore, substantially the same effect can be obtained by replacing part of the electrode with a different type of metal block as shown in FIG.

The columnar electrode of the quadrupole mass spectrometer of the present invention has the effect of improving one-plane accuracy and being lightweight and inexpensive to manufacture.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional columnar electrode, and FIG. 2 is a perspective view of a columnar electrode according to an embodiment of the present invention. Satsuki 10 Dormitory 2 Diagram

Claims (1)

[Claims] 1. In a quadrupole mass spectrometer columnar electrode consisting of two pairs of electrode rods with hyperbolic cross sections on opposing surfaces, the upper electrode rod is made of a conductive material that can be extruded or drawn. A columnar electrode for a quadrupole mass spectrometer, characterized in that the electrode rod is processed to have a V-shaped cross section, and the surface of the electrode rod having a hyperbolic cross section is coated with a corrosion-resistant metal material.