JPH01117253A - Plasma x-ray generation device - Google Patents

Abstract

PURPOSE:To make the accurate open/close control of a gas open/close valve for the ON-OFF control of gas supply to a plasma generation chamber by using a piezoelectric ceramic element as the constituent thereof. CONSTITUTION:A piezoelectric ceramic valve 33 is positionally adjusted with a valve position adjustment micrometer 34 so that a plasma generation chamber will be vacuum, when the valve 33 is closed. Also, the valve 33 is applied with voltage from a power supply 39 and a piezoelectric ceramic element 35 is in an elongated state. On the other hand, when the applied voltage is made zero for the predetermined time, the element 35 contracts and lifts a movable valve 36, thereby opening the valve 33 and introducing the predetermined amount of gases in the plasma generation chamber 11. In order to cope therewith, high voltage is applied from a high voltage power supply 17, an X-ray 21 is generated from a plasma and this X-ray 21 can be taken out via a window 22. By using the piezoelectric ceramic valve 33 as aforementioned, the accurate open/close thereof can be made and a stable X-ray becomes available.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an X-ray generator using discharge plasma, and more particularly to a gas buff type Z-pinch plasma X-ray generator that allows gas to flow in in a pulsed manner only when necessary.

[Conventional technology]

-a, in a gas puff type plasma X-ray generator, in order to cause pulsed gas to flow into the plasma generation chamber only when necessary, electromagnetic force or spring force is used to operate the gas pulp.

FIG. 2 is a cross-sectional view of a conventional plasma X-ray generator, in which 1 is a gas supply chamber, 2 is a gas supply chamber container, 3 is a movable valve, 4 is a solenoid, 5 is an O-ring, and 6 is the switch, 7 is the power supply for the gas valve, 8 is the gas inlet, 9 is the power introduction terminal, 10 is the O+J song 11 is the plasma generation chamber, 1
2 is a high voltage electrode, 13 is an insulating member, 14 is a low voltage electrode, 15
．． 16 is an electrode member, 17 is a high voltage power source for plasma generation, 1
8 is a switch, 19 is an exhaust pump, 20 is a pinch plasma, 21 is an X-ray, 22 is an X-ray extraction window, and 23 is an O-ring.

In the figure, the plasma generation chamber 11 includes an electrode member 15 having a high voltage electrode 12, an electrode member 16 having a low voltage electrode 14,
The electrode member 16 has an X-ray extraction window 22. A high voltage power source 17 for plasma generation is connected to the electrode members 15 and 16 via a switch 18, and the plasma generation chamber 11 is always maintained in a vacuum state by an exhaust pump 19. moreover,
The gas supply chamber container 2 having the gas inlet 8 has an O-ring 23
The gas supply chamber is fixed to the electrode member 15 in an airtight manner via the gas supply chamber.

Inside this container 2, a solenoid coil 4 is fixed to an electrode member 15 via an O-ring 10 for vacuum sealing, and a movable valve 3 consisting of an AA' disk or the like that is moved up and down by the solenoid coil 4 is in contact with the O-ring 5. It is a provision. Both ends of the solenoid coil 4 are connected to the gas supply chamber container l through a power introduction terminal 6 and a switch 6, which are airtightly attached to the gas supply chamber container l.
It is connected to a gas valve power supply 7.

Next, the operation of the X-ray generator having such a configuration will be explained.

Gas is supplied to the gas supply chamber 1 from a gas inlet 8, and the movable valve 3 is normally in close contact with the O-ring 5 due to the pressure difference with the plasma generation chamber 11, so that the gas supply chamber 1 and the plasma generation chamber 11 are connected to each other. is kept airtight. In such a state, when the switch 6 is closed and a steep pulse-like large current is caused to flow through the solenoid coil 4 from the gas valve power source 7 due to discharge of a capacitor, a large magnetic flux is instantaneously generated in the solenoid coil 4. When this magnetic flux passes through the movable valve 3, an eddy current is generated to cancel it, and the magnetic flux generated by this eddy current is in a direction that repels the magnetic flux of the solenoid coil 4. Therefore, the movable valve 3 is driven upward and closes the gas inlet 8, and a gap is created between the movable valve 3 and the O-ring 5.
A predetermined amount of gas flows into. When the pulsed current from the gas valve power supply 7 disappears, the movable valve 3 returns to its original state due to its own weight or spring force, and due to the pressure difference between the gas supply chamber 1 and the plasma generation chamber 11, it is brought into close contact with the O-ring 5. The vacuum of the plasma generation chamber 11 is maintained. In this way, the movable valve is opened for a certain period of time (thereby, a certain amount of gas flows into the plasma generation chamber 11).

When the gas is supplied in this way, the switch 18 is closed in synchronization with the gas supply, and the high-voltage electricity for plasma generation is
High voltage electrode 1
When applied between the electrodes 2 and 14, a large current of several hundred KA flows between the electrodes 12 and 14, the gas is ionized, plasma is generated between the two electrodes, and a magnetic field is generated around the large current. As a result, the plasma is strongly compressed and narrowed to form pinch plasma 20. In such a state, X-rays 21 are generated and can be taken out from the X-ray extraction window 22.

The plasma gradually attenuates as the large current decreases, and the generation of X-rays stops as the current disappears.

[Problem that the invention seeks to solve]

However, when the movable valve 3 serves as a gas opening/closing valve, the shock to the vacuum seal surface during operation is large, and the seal surface may wear out or distortion may occur in the movable valve 3, causing the drive 1 of the movable valve 3 to be interrupted. The gas valve power source 7 is several KV,
Since it requires a pulsed current of several KA, there are problems in that it is large, difficult to handle, and expensive.

The present invention is intended to solve these problems. It reduces the impact when opening and closing the gas, prolongs the life of the gas opening and closing pulp, and ensures reliable opening and closing operation. Plasma x'I with power supply for gas valves
The purpose of the present invention is to provide an a-generating device.

[Means for solving problems]

To this end, the present invention provides a plasma X-ray generator equipped with an on-off valve that controls gas supply to the plasma generation chamber intermittently, and is characterized in that the on-off valve is driven by a piezoelectric ceramic element.

[Effect]

The plasma X-ray generator of the present invention includes a gas opening/closing valve that includes a piezoelectric ceramic element as a component.
It is possible to reduce the impact when opening and closing the valve, to extend the life of the gas on-off valve, and to achieve stable opening and closing operations, downsizing of the power source for driving the gas on-off valve, and reduction in manufacturing costs.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a sectional view of a plasma X-ray generator according to the present invention, in which the same numbers as in FIG. 2 indicate the same contents, 31 is a gas supply chamber, 32 is a gas supply chamber container, 33 is a piezoelectric ceramic valve, 34 is a micrometer for adjusting the valve position, 35 is a piezoelectric ceramic element, 36 is a movable valve, 37, 38 is an O-ring, 39 is a power source for the piezoelectric ceramic valve, and 40 is a voltage introduction terminal.

In the figure, the configurations of a plasma generation chamber II as an X-ray source, a high-voltage power source 17 for plasma generation, an exhaust pump 19, etc. are the same as in the conventional example described above. A gas supply chamber container 32 having a gas introduction port 2 and a voltage introduction terminal 40 is connected to the electrode member 1
5 through an O-ring 37 in an airtight manner, and a vacuum-sealed valve position adjustment micro-make 34 for adjusting the position of the piezoelectric ceramic valve 33 is attached to the top thereof. Moreover, the piezoelectric ceramic valve 33 provided in the gas supply chamber 31 is composed of one or more piezoelectric ceramic elements 3 whose one end is attached to the valve position adjustment micrometer 34 and whose other end is fixed to the movable valve 36.
5. and piezoelectric ceramic element 3
5, a pulse voltage is applied from a piezoelectric ceramic valve power supply 39.

Next, the operation will be explained.

When the piezoelectric ceramic valve 33 is closed, the plasma generation chamber 1
In order to ensure that the valve 1 maintains a vacuum state, the valve position adjusting micrometer 34 adjusts the position 211 to block the gas introduced from the gas inlet 2. When the piezoelectric ceramic valve 33 is closed, a voltage of several hundred μ is always applied from the piezoelectric ceramic valve power supply 39, and the piezoelectric ceramic element 3
5 is in an expanded state. The applied voltage is set to O for a specified period of time.
, the piezoelectric ceramic element 35 shrinks and the movable valve 3
6 is pulled upward, the piezoelectric ceramic valve 33 is kept open for a predetermined period of time, and as a result, a predetermined amount of gas is introduced into the plasma generation chamber. By applying a voltage from the plasma generation high voltage T;,'tA17 at the same time as the introduction of this gas, a plasma state is generated as described above, and X-rays are generated from the plasma. window 2
It can be taken out from 1.

By controlling the voltage applied to the piezoelectric ceramic valve power supply 39 in this manner, it becomes possible to easily open and close the piezoelectric ceramic valve 33 at high speed.

〔Effect of the invention〕

As described above, according to the present invention, by changing the driving method for opening and closing the high-speed opening/closing pulp from a solenoid valve to a piezoelectric ceramic valve, it becomes easy to control the accurate opening/closing speed of the high-speed opening/closing pulp, and the vacuum seal of the movable valve It also reduces impact to the surface, providing stable operation and long life.

Furthermore, since piezoelectric ceramic pulp can be driven at about 100V to 300V, the drive power source can be made smaller and manufacturing costs can be reduced. therefore,
Since plasma can be generated with good reproducibility, stable X-rays can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a plasma X-ray generator according to the present invention;
FIG. 2 is a sectional view of a conventional plasma X-ray generator. 11... Plasma generation chamber, 12... High voltage electrode, 13
... IIAa member, 14 ... Low voltage electrode, 15.16
... Electrode member, 17 ... High voltage power supply for plasma generation,
1st...Switch, 19...Exhaust pump, 20...
・Pinch plasma, 21... X-ray, 22... X-ray extraction window, 31... Gas supply chamber, 32... Gas supply chamber container, 33... Piezoelectric ceramic valve, 34... Valve position i
1 Adjustment micrometer, 35... Piezoelectric ceramic element, 36... Movable valve, 37.38... O ring, 39
...Power supply for piezoelectric ceramic valve, 40...Voltage introduction terminal.

Claims (2)

[Claims] (1) A plasma X-ray generator equipped with an on-off valve for controlling gas supply to a plasma generation chamber intermittently, characterized in that the on-off valve is driven by a piezoelectric ceramic element. (2) The plasma X-ray generation device according to claim 1, wherein the piezoelectric ceramic element comprises one or more piezoelectric ceramic elements.