JPS6326332B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a glow discharge device, and in particular, to a novel improvement for quickly determining the component analysis of a sample attached to a cathode part within a small error range. This increases the electron density within the discharge chamber.

As shown in Japanese Patent Publication No. 49-21680, in this type of device that has been used in the past,
The structure was such that a voltage was applied between the cathode section on which the sample to be measured was attached and the insulated anode section to cause discharge light emission.

However, in such a device it must be possible to determine the component of the material or its component distribution quickly and within a small error range without requiring complicated operations. Incidentally, for such analysis, a rare gas, particularly argon gas, is generally used as the operating gas for generating glow discharge. The sample atoms that are continuously scattered by the impact of the working gas ions are excited, measured by a spectrometer, and quantitatively analyzed, and the accuracy of the analysis is proportional to the intensity of the light. Therefore, the degree of excitation of sample atoms increases with the density of electrons bombarding them, and analysis accuracy improves accordingly.

Various attempts have already been made to apply a large current, low voltage discharge to a glow discharge tube in order to achieve strong excitation.

One method is to use an auxiliary discharge to increase the electron density in the discharge chamber and, therefore, the number of collisions between analysis sample electrons and electrons. However, providing the auxiliary discharge portion requires two auxiliary electrodes in the glow discharge tube, which complicates the structure and control.

In addition, as a method of increasing the electron density in the discharge chamber, a device is installed in the discharge chamber to create an axial magnetic field, which increases the distance the electrons travel due to their spiral motion and increases the number of collisions between the electrons and the atoms in the analysis sample. method is implemented. However, it has the disadvantage that the surface shape after glow discharge changes greatly depending on whether the sample to be analyzed is magnetic or non-magnetic.

The purpose of this invention is to provide an effective means for increasing the electron density within the discharge chamber, and in particular, it is an object of the present invention to provide an effective means for increasing the electron density within the discharge chamber. This is a configuration in which another electrode section is provided.

Hereinafter, preferred embodiments of the glow discharge device according to the present invention will be described in detail with reference to the drawings. The drawing shows a cross section of the glow discharge device according to the present invention, and the entire structure is cylindrical and the necessary through holes are shown on the same plane. A quartz window 3 is placed above the hole 2 formed in the hole 2, and an argon gas introduction pipe 4 is connected to one end of the hole 2.

An anode section 5 is provided at the bottom of the insulator 1,
The hole 2 extends into the anode portion 5, and a first exhaust pipe 6 is provided at one end of the anode portion 5 in a continuous manner with the hole 2. Furthermore, an insulating part 7 and an electrode part 8 are provided in a laminated manner under the anode part 5, and the center part of the electrode part 8 is arranged in a cylindrical shape extending downward and coaxially with the hole part 2. An extended portion 8a is formed.

An insulating part 9 and a cathode part 10 are attached to the lower part of the electrode part 8, a second exhaust pipe 11 is formed at one end of the insulating part 9, and a sample 12 is installed at the lower part of the cathode part 10. It is attached. The distance D between the sample 12 and the extension 8a of the electrode section 8 is approximately 0.1 to 0.3 mm, and the inner diameter of the electrode section 8, that is, the discharge sputter area of the sample 12 is 4.0 to 8.0 mm in diameter.

In the above configuration, when operating the glow discharge device according to the present invention, argon gas is introduced from the argon gas introduction tube 4 into the hole 2 serving as a discharge chamber, and the pressure inside the hole 2 is kept constant. Argon gas is led out from exhaust pipes 6 and 11 for maintenance.

In this state, when a voltage is applied between the anode section 5 and the cathode section 10 of the sample 12, ionization occurs due to the space charge generated between the anode section 5 and the electrode section 8 due to the constant gas pressure conditions. The distribution density of the generated cations becomes denser, and the sample 12 is subjected to initial accelerated excitation. Next, in a stable discharge state, the electrode section 8
A glow discharge occurs in the lower part of the sample 12, that is, in the space near the surface of the sample 12. However, what is desired in this discharge is a high electron density as described above, and the discharge phenomenon is in the region of abnormal glow discharge. In this state, the voltage between the electrode section 8 and the cathode section 10 fluctuates drastically. In other words, it shows the constant current function. However, this constraint region is not so wide; if it is low, there will be insufficient excitation, and if it exceeds the upper limit, instability such as arc discharge will occur. The characteristic structure of the present invention is to control this to a stable region. That is,
Under these conditions, the anode section 5 and the electrode section 8 maintain a capacitive coupling condition within the hole 2, and the electrode interval is wider than the aforementioned interval D between the sample 12 and the extension section 8a. In the stable glow discharge state, both electrodes form a region with a coarser electron density, unlike the above-mentioned abnormal glow discharge. The function of this region is the same as that of a constant voltage discharge tube. Therefore, the electrode section 8 receives voltage stabilization from the anode section 5, and on the other hand, it has two functions of acting on the sample 12 with a high electron density. There is. Next, the unique space charge effect resulting from the structure of the present invention will be described. It consists in automatic control of electron density in the common discharge space. In other words, the electron density acting on the sample 12 and the electron density acting on the anode portion 8 located above the sample 12 have a mutually complementary relationship. This operation is similar to that of a charge control grid of a triode vacuum tube in which the electrode section 8 is leak biased toward the anode side. With this control, the additional voltage for discharge is
It is stabilized even in the range of 700-1500V. As a result, atoms scattered from the sample are strongly excited, light is emitted, and a negative glow region is generated in the upper part of the sample 12. This light is guided through a quartz window 3 to a spectrometer (not shown) and measured.

Since the glow discharge device according to the present invention has the above-described configuration and operation, it has the following effects.

When a voltage is applied between the cathode section and the anode section to cause a discharge, the electrode section has a potential lower than the anode section potential due to the space charge in the discharge chamber, and due to the control action created by this electrode section, the potential near the cathode sample surface This makes it possible to limit abnormalities such as arc discharge while maintaining a high electron density in the negative glow region that occurs in the negative glow region, and control can be performed automatically.

A heterogeneous discharge is generated between the anode part and the electrode part and between the electrode part and the cathode part, and the path of electrons between the cathode part and the cathode part can be lengthened and controlled by the electrode part, and scattering can be caused. The number of collisions between the analysis sample atoms and electrons increases, the degree of excitation of the sample atoms increases, and the intensity of light increases. As can be well understood from the illustrated structure, the feature of the present invention lies in its arrangement, and no claims are made about the shapes and dimensions of the anode portion, the electrode portion, and the insulating portion therebetween. A brim-like protrusion is provided inside the body, and the inner diameter of the electrode part is the same as that of the protrusion, and the insulating part between the two has a wider inner diameter to appropriately set the bond between the two electrodes. Therefore, these dimensions and shapes may be selected depending on the use and purpose of the device.

The potential of the electrode section is controlled by the voltage applied between the anode section and the cathode section, and there is no need for external control.

[Brief explanation of the drawing]

The drawing is a sectional view showing a glow discharge device according to the present invention. DESCRIPTION OF SYMBOLS 1... Insulator, 2... Hole, 3... Quartz window, 4... Argon gas introduction tube, 5... Anode part, 6... First exhaust pipe, 7... Insulating part, 8... Electrode part, 8a... Extension part, 9
...Insulating part, 10...Cathode part, 11...Second exhaust pipe, 1
2...Sample.

Claims (1)

[Claims] 1. In a glow discharge device that causes discharge light emission by applying a voltage between a cathode part on which a sample to be measured is attached and an insulated anode part, an electrode part is provided between the cathode part and the anode part, The electrode part is electrically insulated from the cathode part and the anode part,
A glow discharge device characterized in that when a voltage is applied between the anode part and the cathode part, the potential is lower than that of the anode part due to the effect of space charge.