JPH0317260A - Material vapor generator - Google Patents

Abstract

PURPOSE:To increase the length and diameter of a laser medium by providing pairs of plural electrodes in a discharge space and generating a plurally divided pulse discharge to make uniform the temp. distribution of a buffer gas in the radial direction in the space. CONSTITUTION:The material vapor generator is formed by a vessel 2 having a discharge space 3 filled with a gas, the electrode pairs 13 and 14 opposed to each other in the axial direction (a) in the space 3. The electrode pairs 13 and 14 are arranged at intervals in the radial direction (b) of the space 3 and formed with the electrodes 13a-13c and 14a-14c. An electric discharge is generated in the space 3 to form metal vapor 5. Furthermore, a pulse phase controller for impressing the pulse voltages with the phase successively shifted on the electrodes 13a-13c and 14a-14c is provided.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a substance vapor generating device that utilizes substance vapor as an excitation or ionization medium, and more specifically, to a structure that functions to evaporate a substance.

[Conventional technology]

Examples of this type of material vapor generating device that utilizes fumes include metal vapor laser devices and fumigated ion beam devices. It is a sectional view showing a conventional metal vapor laser device shown in Collection 'l l a IB3, in which la and lb are electrodes for discharging, 2
3 is a discharge tube, 3 is a discharge space for exciting steam, 4 is a metal such as copper gold that is a substance for generating irises, 5 is metal vapor, 6 is a heat insulating layer such as a wool layer, 7a, 7b
3a and 8b are flanges for creating a sealed space, 9 is a vacuum layer, 10 is an insulating cylinder, 11 is a sealed tube, 12a is a gas inlet, and 12b is a gas inlet. . Next, the operation will be explained. A pulse voltage is applied between the electrode pair 1a and lb, and a discharge space 3 is filled with buffer gas.
The discharged ions are discharged. The bathophore gas in the discharge space 3 is heated by the acceleration energy of the electrons, and the metal 4 is evaporated. Ions with high acceleration energy due to pulse discharge,
By colliding electrons and atoms of the heated buffer gas with vaporized metal vapor atoms, the vapor atoms receive and receive energy and are excited to a higher excitation level. The heat insulating layer 6 serves to enhance the gas temperature insulating effect in order to maintain a predetermined vapor density within the discharge space 3. Also, the vacuum layer 9 is the heat insulating layer 6
It has the same role as that of radiant heat. When metal vapor atoms excited to an upper excitation level transition to a lower excitation level or reference level, light is generated. The generated light is amplified by the resonant mirrors 7a and 7b and output as a laser beam to the outside for use in industries such as laser processing.

[Problem to be solved by the invention]

Since the conventional metal vapor laser device is configured as described above, the buffer gas temperature distribution in the radial and axial directions within the discharge space 3 has the characteristics shown in FIG. The temperature of the puffed gas at the pipe wall is lower than that at the pipe wall.
The bumper gas temperature at the end of the discharge tube 2 is low. Therefore, the flower air density distribution in the discharge space 3 can be approximately approximated to the saturated vapor density n0, which is a function of the bathophore gas temperature. As shown in FIG. 8, the vapor density spatial distribution in the radial direction has characteristics nl, n2, and n3. (nl>n2=n3
) On the other hand, when the vapor density increases relative to the buffer gas density (gas pressure), the mean free path of electrons, buffer gas ions, and neutral atoms until they collide with the vapor atoms becomes shorter; The problem was that the kinetic energy of electrons, buffer gas ions, and neutral atoms obtained by pulsed discharge decreased, and as a result, the probability that vapor atoms could be excited to a higher excitation level decreased, making it impossible to obtain laser gain. Furthermore, in the current device where the vapor density is high at the center of the discharge space 3, there is a problem that the laser power density is low at the center of the discharge space 3. The inventions according to the first to third claims have been made in order to solve the above-mentioned problems, and it is possible to make the temperature distribution of the buffing gas substantially uniform in the radial direction within the discharge space, and to improve the vapor density and the buffing gas. The object of the present invention is to obtain a material aeration generating device that can increase the spatial area in which the temperature satisfies the optimum conditions for laser oscillation and also lengthen the period of laser oscillation.

[Means to solve the problem]

In the substance vapor generating device according to claim i, a pair of electrodes are arranged to face each other in the axial direction in a discharge space in which a gas is sealed in a container, and a pulse discharge between the electrode pair causes a substance to be generated in the discharge space. In the substance vapor generating device for generating vapor, at least one of the electrode pairs is composed of a plurality of electrodes, and the plurality of electrodes are arranged at intervals in the radial direction within the discharge space. The substance vapor generating device according to the second aspect is provided with a pulse phase control device that applies a pulse voltage whose phase is sequentially shifted to the plurality of electrodes. In the substance vapor generating device according to the third aspect, a tube B is provided between each of the plurality of electrode pairs.

[For use]

The material gas generation device according to the first aspect generates a plurality of divided pulse discharges in a radial direction within a discharge space by applying a pulse voltage to each of the plurality of electrodes, Since the buffer gas can be heated almost uniformly in the radial direction within the discharge space in multiple divided regions,
The temperature distribution of the bumper gas in the radial direction within the discharge space can be made almost uniform, and the length and diameter of the laser medium can be expanded. Moreover, the time for laser oscillation per unit time increases due to the plurality of pulse discharges divided into a plurality of parts in the radial direction within the discharge space. In addition to the above-mentioned effects, the substance vapor generating device according to the second claim applies a pulse voltage whose phase is sequentially shifted to a plurality of electrodes to generate a plurality of regions divided in the radial direction within the discharge space. Since it is possible to generate pulsed discharges whose phases are sequentially shifted from each other, by lowering the lower level to the base level during the pulse discharge stop period in each pulsed discharge space, the vapor atoms are generated by the pulsed discharge at each electrode pair. It is possible to suppress an increase in the number of atoms excited to the lower level level. In the substance vapor generating device according to the third claim, since the tube B is provided for each discharge pair, the vapor atoms are caused to collide with the tube B during the stop period of the pulse discharge, and the lower level level is lowered to the base level. By promoting the drop in vapor atoms to lower levels, it is possible to suppress an increase in the number of vapor atoms excited to the lower level level by pulse discharge at each electrode pair.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a vertical cross-sectional view of the main parts of the first embodiment of the metal vapor laser device, and the same or equivalent parts as in FIG. 7 are given the same reference numerals and redundant explanation will be omitted. In FIG.
A pair of electrodes arranged facing each other from the direction of arrow a),
These electrode pairs 13, 14 are a plurality of electrode pairs 13a. 13b, 13c and 14a, 14b, 14c. 15a. 15b, 15c are a plurality of electrode pairs 13a. 1
A plurality of power supplies apply pulse voltages between 3b, 13c and 14a, 14b, 14c, respectively. Next, the operation will be explained. Multiple electricity iffl5a,1
5b, 15c, a plurality of electrode pairs 13a, 13b,
By applying pulse voltages between 13c and 14a, 14b, and 14c, a plurality of divided pulse discharges are generated in the radial direction within the discharge space 3 filled with bumper gas, The metal 4 in the discharge space 3 is melted to obtain metal vapor. Laser light is obtained by exciting the metal vapor to an upper level level by the plurality of pulse discharges. Since the fer gas can be heated almost uniformly in the radial direction, the temperature distribution of the bath fer gas in the radial direction in the discharge space 3 becomes almost uniform, the laser medium length and diameter can be expanded, the laser output is increased, and the laser output is increased. be enhanced. Also,
Due to the plurality of divided pulse discharges in the discharge space 3, the laser oscillation time per unit time increases, so that the laser output is increased. Next, FIG. 2 shows a modification of the first embodiment, in which one of the electrode pairs 13 and 14 is replaced by a plurality of electrodes 13.
a. r! by 13b and 13c! t and the other 14 to 1
This configuration has two common electrodes, and the same effect as in FIG. 1 can be obtained. Next, FIG. 3 is a vertical cross-sectional view and a cross-sectional view of the main part showing a second embodiment of the material vapor laser device, and in this case, a plurality of electrode pairs 13a, 13b, 13c and 14a, 14b, 14C
a plurality of tubes 16a each facing these between;
16b and 16c are arranged within the discharge space 3 substantially parallel to its axial direction (direction of arrow a). At this time, as shown in FIG. 4, the plurality of tubes 16a,
16b, 16c are provided with a plurality of protrusions or holes 17 on their circumferential surfaces, or with tubes 16a. Preferably, 16b and 16c are made of porous material. According to this second embodiment, in addition to the effects of the first embodiment, the atoms of the vapor excited to the lower level level, which is the cause of suppressing the increase in laser output, are caused by collisions with the plurality of tubes. Since the vapor can quickly return to the ground level and the number of atoms in the vapor excited to the lower level can be relaxed, the laser output can be increased. At this time, as shown in FIG.
b. If a plurality of protrusions or holes 17 are provided around the tube 16c, or if the tubes 16a, 16b, and 16c are made of porous material, the discharge space 3 can be discharged through the plurality of protrusions or holes 17.
Convection works within the M electric space 3 to make the bumper gas temperature and vapor density approximately uniform. As a result, each electrode pair 13a. 13b, 13c and 14a. 14
It is possible to make the laser quality such as the laser peak value and directivity of laser oscillation for each of b and 14c almost uniform. Next, FIG. 5 is a longitudinal sectional view of the main part showing a third embodiment of the metal vapor laser device, in which a plurality of power supplies 1
Pulse phase control device 1 at 5a, 15b, 15c
8 are connected. According to this third embodiment, a plurality of pulse signals S+. By supplying St, St, these plural power sources 15a, 15b, 15c
a plurality of electrode pairs 13a. 13b13c and 14a
．． A pulse voltage is applied between each of 14b and 14c. At this time, as shown in FIG. 6, the second power source 15b and the third power source 1
5c, the phases of the pulse signals S2 and S3 are sequentially adjusted for a time T+. Shift only Tz. As a result, electrode pair 1
3a. 14a, 13b, 14b, 13c, 14
c, the phase is time T. ,T. This is to apply pulse voltages that are shifted in steps. Therefore, according to this third embodiment, in addition to the effects of the first embodiment, a plurality of electrode pairs 1 3a, 13b, 13c
and 14a. In order to generate a pulsed discharge whose phase is sequentially shifted in a plurality of regions divided in the radial direction within the discharge space 3 by applying a pulsed voltage whose phase is sequentially shifted between 14b and 14c, by the pulsed discharge, As the vapor atoms excited to the upper level fall to the lower level, the number of atoms in the lower level increases. This increased number of atoms at the lower level can be returned to the base level during the pulse discharge stop period, and the number of atoms at the lower level can be suppressed, making it possible to increase the laser output. can. Further, in the above embodiments, a metal vapor laser device was explained, but a material generating device and a high temperature furnace may also be used.
The same effects as in the above embodiment are achieved.

【Effect of the invention】

As described above, according to the invention according to the first claim,
By generating a plurality of divided pulse discharges in a radial direction within the discharge space, the temperature distribution of the bumper gas in the radial direction within the discharge space can be made almost uniform;
Since the laser medium length can be expanded and the time for laser oscillation per unit time can be increased, the laser output can be increased. Further, according to the invention according to the second claim, in addition to the above-mentioned effects, by generating a pulse discharge whose phase is sequentially shifted in a plurality of regions divided in the radial direction within the discharge space,
In each pulse discharge space, the lower level level can be returned to the base level during the pulse discharge stop period, and the number of vapor atoms excited to the lower level level by the pulse discharge at each electrode pair can be suppressed from increasing. Therefore, it has the effect of increasing laser output. Further, according to the invention according to the third claim, in addition to the above-mentioned effects, since the tube B is provided in the discharge space, collisions between vapor atoms and the tube wall occur frequently during the stop period of pulse discharge. The effect of returning the lower level to the base level is promoted, which has the effect of increasing the laser output period and laser output.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the main parts of a metal fume laser device according to a first embodiment of the present invention, FIG. 2 is a vertical sectional view showing a modification of the same, and FIG. 3 is a second embodiment. FIG. 4 is a perspective view showing a tube used in the metal vapor laser device according to the above, and FIG. 5 is a main part of the metal vapor laser device according to the third embodiment. FIG. 6 is a pulse signal waveform diagram of the pulse phase control device used in the metal vapor laser device mentioned above, FIG. 7 is a longitudinal cross-sectional view showing the conventional metal vapor laser device, and FIG. 8 is a diagram showing the distribution of the breadfer gas temperature and vapor density in the same as above. 2 is a discharge tube (container), 3 is a discharge space, 5 is a metal vapor, 1
3.14 is an electrode pair, l 3 a, 1 3 h, 13 c
and 14a. 14b, 14c are electrodes, 15a15b.
15c is a power supply, 16a. 16b. 16c is a tube, 18 is a pulse phase control device. The same reference numerals throughout the country indicate the same or equivalent parts. Patent applicant Mitsubishi Electric Co., Ltd. 2: 15ft official (photograph) 15o, 15b, +5c electric J

Claims (3)

[Claims] (1) A substance vapor generation device comprising a container having a discharge space filled with gas, and a pair of electrodes arranged axially facing each other in the discharge space and generating substance vapor by electric discharge in the discharge space. 2. A substance vapor generation device according to claim 1, wherein at least one of the pair of electrodes is composed of a plurality of electrodes arranged at intervals in a radial direction of the discharge space. (2) The substance vapor generating device according to claim 1, further comprising a pulse phase control device that applies a pulse voltage whose phase is sequentially shifted to the plurality of electrodes. (3) The substance vapor generating device according to claim 1 or 2, characterized in that a tube B is provided for each of the plurality of electrode pairs.