JP3740336B2 - Particle beam equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a particle beam device used to heat the plasma of a fusion device.
[0002]
[Prior art]
In general, a particle beam apparatus is an apparatus that generates charged particles with an ion source, extracts the generated charged particles from the ion source, accelerates them, and heats the plasma of the fusion apparatus.
[0003]
A conventional example of a particle beam apparatus will be described with reference to FIG. In FIG. 7, a conventional particle beam apparatus includes an ion source 1, a filament power source 2 for supplying a current to a filament 5 in the ion source 1, an arc power source 3, a bias power source 4, and first to third electrodes 6 and 8. , 10, an extraction power source 7 and an acceleration power source 9.
[0004]
In the particle beam apparatus configured as described above, the filament power source 2 is a power source that heats the filament 5 by supplying a current of several hundreds A to several tens of filaments 5. The arc power source 3 is a power source for generating ion particles by applying a voltage of about 100 V between the filament 5 and the wall of the ion source 1. The bias power source 4 is a power source that controls the amount of electrons emitted by applying a voltage of about 10 V between the wall of the ion source 1 and the first electrode 6. The first electrode 6 is disposed at the opening end of the ion source 1 and connected to the bias power source 4 and the extraction power source 7.
[0005]
The extraction power source 7 is a power source that applies a voltage of about 10 Kv between the first electrode 6 and the second electrode 8 to extract charged particles. The acceleration power source 9 is a power source that applies a voltage of several tens kV to several hundreds kV between the second electrode 8 and the third electrode 10 and accelerates charged particles by a potential difference between the electrodes 8 and 10. The second electrode 8 is provided directly below the first electrode 6 and connected to the extraction power supply 7 and the acceleration power supply 9, and the third electrode 10 is provided directly below the second electrode 8 and connected to the acceleration power supply 9. is doing.
[0006]
FIG. 8 shows an operation time sequence of each of the power supplies 2, 3, 4, 7 and 9 constituting the particle beam apparatus. First, the filament power source 2, the bias power source 4, and the arc power source 3 are raised in this order to pre-ionize the particles, and then the arc power source 3 is once lowered. Thereafter, the acceleration power source 9, the extraction power source 7, and the arc power source 3 are started in this order to extract the particle beam.
[0007]
[Problems to be solved by the invention]
In the conventional particle beam apparatus, there is a problem that the output voltage of the bias power source 4 varies depending on ON / OFF (on / off) of the arc power source 3. FIG. 9 shows the time sequence of the arc power source 3 and the output voltage variation of the bias power source 4. This shows the relationship. When the arc power source 3 is turned on for the first time, the output voltage of the bias power source 4 decreases, that is, drops. At this point, since the beam is not drawn, fluctuations in the output voltage of the bias power source 4 affect the performance of the apparatus. Never give.
[0008]
However, when the arc power supply 3 is turned off, the output voltage of the bias power supply 4 jumps greatly and greatly exceeds the set value. The control response speed of the bias power supply 4 is slowed to suppress interference with other power supplies, and the output voltage of the bias power supply 4 still exceeds the set value when the arc power supply 3 is turned on next time. The control works in the direction of lowering the voltage.
[0009]
Accordingly, the output voltage of the bias power supply 4 drops significantly more than the first time by turning on the arc power supply 3 for the second time. Since the beam is extracted at this stage, there is a problem that the electron emission amount cannot be controlled during the period when the output voltage of the bias power supply 4 is lowered, and the beam quality is deteriorated.
[0010]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a particle beam apparatus capable of suppressing a voltage drop of a bias power source at the start of beam extraction and emitting a high-quality beam.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, in the particle beam apparatus according to the present invention, in the invention corresponding to claim 1, an ion source, a filament power source for supplying current to the filament in the ion source and heating, the filament and the filament An arc power source for applying a voltage to the wall of the ion source to generate ion particles, a bias power source for applying a voltage to the wall of the ion source and the first electrode, and a second electrode disposed below the first electrode In a particle beam apparatus provided with an extraction power source for applying a voltage to a voltage source, an addition circuit for adding a constant value to the output reference value of the bias power source for a predetermined time from the time when both the arc power source and the extraction power source are turned on It is characterized by providing.
[0012]
In the particle beam apparatus with the above configuration, when the output voltage of the bias power supply drops, the bias power supply output set value is increased, so that the voltage recovery time is shortened to suppress the fluctuation of the bias output voltage, and the quality is high. A particle beam device for emitting a beam can be provided.
[0013]
The amount added to the output reference value of the bias power supply is preferably a function of time. In this case, it is possible to finely correct the drop in the output voltage of the bias power supply.
[0014]
In the invention corresponding to claim 2, an ion source, a filament power source for heating the filament in the ion source by supplying a current, and an arc power source for generating ion particles by applying a voltage to the filament and the wall of the ion source In the particle beam apparatus, comprising: a bias power source for applying a voltage to the wall of the ion source and the first electrode; and an extraction power source for applying a voltage to the second electrode disposed below the first electrode. A subtracting circuit for subtracting a constant value from the output reference value of the bias power source for a certain time from the time when the power is turned off is provided.
[0015]
In the particle beam apparatus having the above configuration, since the output setting value of the bias power supply is lowered when the output voltage of the bias power supply jumps, the voltage recovery time is shortened, and the output of the bias power supply when the arc power is turned on for the second time is shortened. The amount of voltage drop decreases.
[0016]
It is preferable that the amount subtracted from the output reference value of the bias power source from the time when the arc power source is turned off is a function of time. In this case, it is possible to finely correct the jump in the output voltage of the bias power source.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of a particle beam apparatus according to the present invention will be described with reference to FIGS.
[0018]
Since the basic configuration of the particle beam apparatus in the present embodiment is almost the same as that in FIG. 7, the description of the configuration of the apparatus is omitted, but the difference of this embodiment from the conventional example is shown in FIG. 1. As described above, the addition circuit 11 for adding a constant voltage to the bias power supply output reference for a certain time when the three conditions of the arc power supply ON, the extraction power supply ON, and the bias power supply ON are prepared.
[0019]
In this embodiment, as shown in FIG. 2, the bias power supply output command value is higher than the conventional bias power supply output reference by a certain time, so that the drop time of the bias power supply output voltage is shortened. FIG. 2 shows the relationship between the time sequence of the arc power supply and the output voltage fluctuation of the bias power supply shown in comparison with FIG.
[0020]
According to the present embodiment, since a constant value is added to the output reference value of the bias power source for a certain time from the time when both the arc power source and the extraction power source are turned on, when the output voltage of the bias power source falls The output set value of the bias power supply becomes high, and the voltage recovery time can be shortened.
[0021]
Next, a second embodiment of the particle beam apparatus according to the present invention will be described with reference to FIGS.
As shown in FIG. 3, this embodiment is different from the conventional example in that a subtracting circuit 12 for subtracting a constant voltage from a bias power supply output reference for a certain time when the arc power supply is turned off is provided. Since other points are almost the same as the conventional example, the description of the configuration is omitted.
[0022]
In the present embodiment, as shown in FIG. 4, the bias power supply output command value is lower than the conventional bias power supply output reference by a certain time, so that the jump time of the bias power supply output voltage is shortened. FIG. 4 shows the relationship between the time sequence of the arc power supply and the output voltage fluctuation of the bias power supply shown in comparison with FIG.
[0023]
According to the present embodiment, when a constant value is subtracted from the output reference value of the bias power source for a certain time from the time when the arc power source is turned off, the output setting value of the bias power source when the output voltage of the bias power source jumps up Therefore, the voltage recovery time is shortened, and the drop amount of the output voltage of the bias power source at the time of the second arc power ON can be reduced.
[0024]
Next, a third embodiment of the particle beam apparatus according to the present invention will be described with reference to FIG.
In this embodiment, in the first embodiment, as shown in FIG. 5, when three conditions of arc power ON, extraction power ON, and bias power ON are satisfied, an added voltage [f (t) ] Is added to the bias power supply output reference.
[0025]
In the present embodiment, the bias power supply output command value is higher than the conventional bias power supply output reference by a time function, so that the drop time of the bias power supply output voltage is shortened.
[0026]
According to the present embodiment, the bias power supply is added to the output reference value of the bias power supply by the time function from the time when both the arc power supply and the extraction power supply are turned on. The output set value is increased, the voltage recovery time can be shortened, and the voltage recovery curve can be finely adjusted.
[0027]
Next, a fourth embodiment of the particle beam apparatus according to the present invention will be described with reference to FIG.
In the second embodiment, as shown in FIG. 6, when the arc power supply is turned off, a subtraction voltage consisting of a time function [g (t)] is subtracted from the bias power supply output reference in the second embodiment. The function subtracting circuit 14 is configured.
[0028]
In the present embodiment, the bias power supply output command value is lower than the conventional bias power supply output reference by a function of time, so the jump time of the bias power supply output voltage is shortened.
[0029]
According to the present embodiment, the bias power supply output reference value is subtracted from the bias power supply output reference value by the time function from the time when the arc power supply is turned off, and the bias power supply output set value is lowered when the output voltage of the bias power supply jumps. The voltage recovery time can be adjusted to be short and fine, and the amount of drop in the output voltage of the bias power supply at the time of the second arc power ON can be reduced.
[0030]
【The invention's effect】
In the particle beam apparatus of the present invention, in the first aspect of the invention, since a constant value is added to the output reference value of the bias power source for a certain period from the time when both the arc power source and the extraction power source are turned on, beam extraction starts. It is possible to provide a particle beam apparatus that suppresses the voltage drop of the bias power source and emits a high-quality beam.
[0031]
In addition, by adding the bias power output reference value for the time function from the time when both the arc power supply and the extraction power supply are turned on, the voltage drop of the bias power supply at the start of beam extraction is suppressed, and a high quality beam is An emitting particle beam device can be provided.
[0032]
According to the second aspect of the present invention, since the constant value is subtracted from the output reference value of the bias power source for a certain time from the time when the arc power source is turned off, the voltage drop of the bias power source at the start of beam extraction is suppressed, and the quality is reduced. It is possible to provide a particle beam device that emits a high beam.
[0033]
Also, by subtracting the bias power output reference value from the bias power output reference value by the time function from the time the arc power is turned off, the particle power beam that emits a high-quality beam is suppressed by suppressing the voltage drop of the bias power at the start of beam extraction An apparatus can be provided.
[Brief description of the drawings]
FIG. 1 is a circuit diagram for explaining a first embodiment of a particle beam apparatus according to the present invention;
2 is a diagram showing the relationship between the time sequence of the arc power supply of the particle beam apparatus in FIG. 1 and the output voltage fluctuation of the bias power supply.
FIG. 3 is a circuit diagram for explaining a second embodiment of the particle beam apparatus according to the present invention;
4 is a diagram showing the relationship between the time sequence of the arc power supply of the particle beam apparatus in FIG. 2 and the output voltage fluctuation of the bias power supply.
FIG. 5 is a circuit diagram for explaining a third embodiment of the particle beam apparatus according to the present invention;
FIG. 6 is a circuit diagram for explaining a fourth embodiment of the particle beam apparatus according to the present invention;
FIG. 7 is a schematic diagram schematically illustrating a conventional particle beam apparatus.
FIG. 8 is a diagram showing each power supply time sequence of a conventional particle beam apparatus.
FIG. 9 is a diagram showing the relationship between the time sequence of the arc power supply and the output voltage fluctuation of the bias power supply of a conventional particle beam apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Ion source, 2 ... Filament power supply, 3 ... Arc power supply, 4 ... Bias power supply, 5 ... Filament, 6 ... 1st electrode, 7 ... Extraction power supply, 8 ... 2nd electrode, 9 ... Acceleration power supply, 10 ... 3rd electrode, 11 ... addition circuit, 12 ... subtraction circuit, 13 ... function addition circuit, 14 ... function subtraction circuit.

Claims (2)

An ion source, a filament power source for supplying current to a filament in the ion source and heating it, an arc power source for generating ion particles by applying a voltage to the filament and the wall of the ion source, and a wall of the ion source and the first In the particle beam apparatus including a bias power source for applying a voltage to the electrode of the first electrode and an extraction power source for applying a voltage to the second electrode disposed below the first electrode, both the arc power source and the extraction power source are turned on. A particle beam apparatus comprising an adder circuit for adding a constant value to an output reference value of the bias power source for a predetermined time from a certain time. An ion source, a filament power source for supplying current to a filament in the ion source and heating it, an arc power source for generating ion particles by applying a voltage to the filament and the wall of the ion source, and a wall of the ion source and the first In a particle beam apparatus equipped with a bias power source for applying a voltage to the first electrode and an extraction power source for applying a voltage to the second electrode disposed below the first electrode, a constant from the time when the arc power source is turned off. A particle beam apparatus comprising a subtracting circuit for subtracting a constant value from an output reference value of the bias power source for a period of time.

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