JPS5950343B2 - Ion wind focusing method using corona discharge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ion wind focusing method for blowing focused ion wind onto an object using corona discharge.

Conventionally, there has already been a method of blowing ion wind onto a part of the object by arranging a discharge electrode to face the pressure object and causing corona discharge between the two. Proposed.

When generating ion wind by this type of method, the present invention focuses and releases the ion wind by arranging an ion wind control electrode between the discharge electrode and the object to be subjected to wind pressure,
Moreover, by appropriately selecting the shape of both electrodes and the distance between them,
This is characterized by increasing the blowing flow pressure of the focused and emitted ion wind or making the blowing flow pressure distribution uniform, thereby further enhancing the blowing effect.

To explain the method of the present invention in more detail with reference to the drawings, in FIG. Furthermore, the discharge electrodes 2 are connected to the negative terminals.

The ion wind control electrode 4 arranged between the wind pressure object 1 and the discharge electrode 2 has an opening 5 at the center facing the tip of the discharge electrode 2, and has an opening 5 around the opening 5 facing the discharge surface 2a of the discharge electrode 2. It has a discharge surface 4a and is grounded via a resistor R.

The discharge surface 2a of the discharge electrode 2 is formed into a conical shape with an apex angle of approximately 60 degrees, and the discharge surface 4a of the ion wind control electrode 4 has an opening angle of 60 degrees parallel to the discharge surface 2a. It is shaped like a mortar.

When a high voltage is applied between the discharge electrode 2 and the ion wind control electrode 4 having such a configuration to cause a corona discharge between the two electrodes, the wind pressure increases through the opening 5 of the ion wind control electrode 4 due to the corona discharge. A blowout flow of ion wind toward the object 1 is generated and blown onto the object 1 subjected to wind pressure.

- Adjustment of the speed, volume, etc. of this ion wind involves selecting the shapes of the discharge electrode 2 and the ion wind control electrode 4, adjusting the distance between the two electrodes, selecting the diameter ratio of both electrodes, and resistors connected to the ion wind control electrode 4. This can be done by adjusting R, etc.
In particular, with regard to the shapes of the discharge electrode 2 and the ion wind control electrode 4, the present inventor formed the discharge surface 2a of the discharge electrode 2 into a conical shape with an apex angle of approximately 60° as described above, and the ion wind control electrode 4. It was experimentally confirmed that a strong ion wind could be generated by forming the discharge surface 4a parallel to the discharge surface 2a in a mortar shape with an opening angle of about 60 degrees.

Further, the ion wind blown out from the opening 5 of the ion wind control electrode 4 due to such corona discharge between the two electrodes generally has a high blowout flow pressure at the center of the opening 5 and a low pressure at the periphery.

However, in experiments conducted by the present inventor, it was found that by appropriately adjusting the distance between the two electrodes, the distribution of the pressure of the ion wind blowing out over the entire opening 5 could be made uniform.

In this case, it is more effective to make the diameter of the discharge electrode 2 and the opening diameter of the ion wind control electrode 4 substantially the same.

By arranging the discharge electrode 2 and the ion wind control electrode 4 in parallel as described above and increasing the applied voltage and discharge current to obtain a high electric field strength, a strong ion wind can be generated, and at the same time, the distance between the electrodes can be set appropriately. It is considered that by adjusting the electric field to adjust the electric field, it is possible to obtain a parallel flow of ion wind with a substantially uniform distribution of blowout flow pressure.

Figure 2 shows the effect of the mutual influence of the apex angle α of the discharge electrode and the opening angle β of the ion wind control electrode on the pressure of the ion wind blowing flow using the discharge electrode and ion wind control electrode shown in the figure. This shows the experimental results that confirmed this, and it can be seen that a strong ion wind can be obtained when both α and β are approximately 60°.

In addition, Figure 3 shows the results of an experiment to confirm the effects of the discharge electrode apex angle α and the electrode spacing on the electric wind blowout flow using the discharge electrode and ion wind control electrode shown in the figure. This also shows that a strong ion wind can be obtained when the apex angle of the discharge electrode is approximately 60°, and that appropriate setting of the electrode spacing is effective in obtaining the strength of the ion wind.

In addition, in the graphs in Figures 2 and 3 above, in order to make it easier to understand, the trends in increase and decrease in measured values are shown by connecting each measurement point in a straight line. When measurements are performed, it is considered that the measured values are lined up on a line connecting the measurement points with a smooth curve.

Therefore, if we also take into account the experimental results described in Japanese Patent Publication No. 17176/1987, which are related to the invention of the present inventors, the above curve can be determined by adjusting the electrode apex angle and the control electrode in order to obtain a large total pressure of ion wind. It is effective that the aperture angle does not fall below 50° and that the electrode apex angle does not exceed 70° and approach the unstable region, that is, by keeping these angles within an angular range of approximately 60°. , a stronger ion wind can be obtained than in the case outside this range.

Figures 4a-C illustrate experimental results regarding the distribution of blowout flow pressure when the ion wind associated with corona discharge is focused by the ion wind control electrode and the ion wind is released onto the surface of the object being subjected to wind pressure. Figures a, l) and C respectively show the case where the distance between the electrodes is 0.5.10 mm.

In this experimental example, when the distance between the electrodes is 5 mm, the distribution of the pressure of the blowing flow from the opening of the ion wind control electrode is approximately uniform throughout the opening, and when the distance between the electrodes is smaller than that, Or, in the case of large, the wind pressure at the center of the opening is higher than that at the periphery, and as the distance between the electrodes increases, the maximum wind pressure increases.

Note that the distance between the electrodes when the distribution of the pressure of the ion wind blowing out is approximately uniform is 5 mm in the above experimental example.
It changes depending on other conditions such as electrode shape.

However, the positions of the electrodes where the pressure distribution is approximately uniform can be easily found by measuring the pressure distribution while changing the distance between the electrodes.

As is clear from the detailed description above, according to the method of the present invention, by appropriately selecting the shapes of the discharge electrode and the ion wind control electrode and the distance between the electrodes, the blowout flow pressure of the ion wind that is not collected and released can be reduced. The spraying effect can be effectively utilized depending on the application by increasing the pressure or making the pressure distribution uniform.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an outline of an apparatus for carrying out the method of the present invention, and FIGS. 2, 3, and 4 a to 4 are explanatory diagrams showing experimental results related to the present invention. 1... Wind pressure object, 2... Discharge electrode,
3... Power supply, 4... Ion paper control electrode, 2a, 4a... Discharge surface, 5... Opening.

Claims (1)

[Claims] 1. A high voltage is applied between a discharge electrode and an ion wind control electrode having an opening opposite to the tip at the center of the discharge surface to control the ion wind caused by corona discharge between the two electrodes. When spraying onto an object from the opening, the discharge surface of the discharge electrode is formed into a conical shape with an apex angle of approximately 60°, and the discharge surface of the ion wind control electrode is formed parallel to the discharge surface of the discharge electrode. A method for converging ion wind by corona discharge, characterized in that the opening angle is formed in a mortar shape with an opening angle of approximately 60°, and a strong flow of ion wind is obtained from the opening as corona discharge occurs between both electrodes. 2. A high voltage is applied between the discharge electrode and an ion wind control electrode that has an opening at the center of the discharge surface facing the tip of the discharge electrode, and the ionic wind caused by the corona discharge between the two electrodes is directed from the opening to the object. When spraying, the discharge surface of the discharge electrode is formed into a conical shape with an apex angle of approximately 60°, and the discharge surface of the ion wind control electrode is formed so that the opening angle parallel to the discharge surface of the discharge electrode is approximately 60°. By adjusting the distance between the two electrodes, the pressure distribution of the ion wind blown out from the aperture, which is generated due to the corona discharge between the two electrodes, can be made approximately uniform over the entire aperture. A method for converging ion winds using corona discharge, which is characterized by: