JPH03280618A - Gas switch deriving circuit and discharge stimulation laser and accelerator using the circuit - Google Patents

Abstract

PURPOSE:To apply the gate trigger pulse voltage with a steep starting time to protect a pulse generating circuit by applying a gate trigger pulse voltage to a gate trigger input of a gas switch via a saturable reactor. CONSTITUTION:A gate trigger pulse voltage is applied to a gate trigger input of a gas switch 27 via a saturable reactor 10 connecting to an output terminal of a pulse generating circuit comprising a DC power supply 1 deciding the gate trigger pulse voltage and a semiconductor switch element 4 generating the gate trigger pulse voltage. Thus, the gate trigger pulse voltage with a steep leading time is applied to the gas switch 27, a high voltage surge induced at the gate trigger input when main electrodes of the gas switch 27 are turned on is blocked by the saturable reactor 10 to protect components of the pulse generating circuit.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to discharge-excited lasers such as excimer lasers that utilize high-voltage pulse generation circuits using gas switches such as thyratrons, or accelerators such as linear induction accelerators. This invention relates to a gas switch drive circuit for operating a gas switch, a discharge excitation laser using the same, and an accelerator.

[Conventional technology]

Excimer laser, TEMA (Transverse
lyExcited Multi-Atomosphere
BACKGROUND ART Discharge-excited lasers such as -Cox lasers and copper vapor lasers are being studied in various application fields for starting chemical reaction processes such as lithography, uranium isotope separation, and CVD.

In order to efficiently oscillate such a discharge-pumped laser, it is necessary to apply a high voltage (about several tens of kV or more) to the laser main discharge electrode for a short time (about several hundred ns or less). In this case, a high repetition rate high voltage pulse generation circuit as shown in FIG. 8 is used. In this circuit, 51 is a high voltage DC power supply, 52 is a charging resistor for the main capacitor 53, 27 is a gas switch called thyratron, 28 is an anode of thyratron 27, 29 is a cathode of thyratron 28, and 14 is a control terminal for thyratron 27. Gate trigger input terminal called grid,
25 is an auxiliary grid, 53 is a main capacitor, 54, 56
．． 59 is an inductance generated by generation, 55 is an inductance for charging the main capacitor 53, and 57 is a tJ V (tll
traViolet: ultraviolet) pre-ionization gap,
58 is a peaking capacitor.

In this circuit, during the off period of the thyratron 27, the main capacitor 53 is connected to the positive terminal of the DC power supply 51, the resistor 52, the main capacitor 53, the inductance 54.55, and the DC power supply 51.
By the charging current flowing through the negative electrode path of No. 1, the battery is charged to the polarity shown in the figure, usually to about 30 kV. In addition, in order to maintain the off state, the control grid 14 of the thyratron 28
A negative polarity DC bias voltage (usually about several hundred volts) is applied to the auxiliary grid 25, and a positive polarity DC bias voltage (usually about several hundred volts) is applied to the auxiliary grid 25.

After a positive gate trigger pulse voltage of about 1 kV is applied superimposed on the negative DC bias voltage of the control grid of the thyratron 27, the voltage between the main electrodes of the thyratron 27 (anode 28 and cathode 29) breaks down, and thyratron 27
turns on. As a result, the charge accumulated in the main capacitor 53 is transferred from the illustrated positive electrode to the thyratron 27 and U.
■Pre-ionization gap 57, peaking capacitor 58
, the inductances 56 and 54, and the main capacitor 53 through a path on the load side shown in the figure, which causes the discharge current to flow to the peaking capacitor 58. The main discharge electrode 60 is pre-ionized by the U-light generated when the U-preliminary ionization gap 57 breaks down.

When the charging voltage of the peaking capacitor 58 reaches the breakdown voltage of the main discharge electrode 60, the charge stored in the capacitor is transferred from the positive electrode of the capacitor 58 to the laser main discharge electrode 60, to the inductance 59, not shown. Most of the energy flows through the load path of the capacitor 58, passes through the laser main discharge electrode 60, is consumed in the laser gas, and contributes to laser oscillation.

Forward direction flowing through the thyratron 27 (current flowing from the anode 28 to the cathode 29 of the thyratron 27).
Approximately several tens of microseconds after the main electrodes of the thyratron 27 are stopped, the connection between the main electrodes of the thyratron 27 is turned off, and the above operation is repeated.

As a thyratron drive circuit used in the above-described high-repetition high-voltage pulse generation circuit, for example, as shown in FIG. 6, a structure using a semiconductor switching element such as a MoS-FET is used.

In the figure, 1 is the positive terminal of the DC power input of the gate trigger pulse generation circuit, 2 is the charging resistance of the capacitor 3, and 4
5 is the gate of the semiconductor switch element 4; 6 is the diode; 7 is the transformer; 8 is the primary winding of the transformer 7; 9 is the transformer 7;
13 is the control of the thyratron 27.
A capacitor for blocking the DC bias current of the grid 18, 14 a control grid of the thyratron 27, 18 a DC bias power supply for the control grid 14 of the thyratron 27, 19 a resistor, 20 an inductance for blocking surge voltage, 21 a A varistor, 22 is a DC bias power supply for the auxiliary grid 25 of the thyratron 27, 23 is a resistor, 24 is an inductance for blocking surge voltage, 25 is an auxiliary grid for the thyratron 27, 26 is a varistor, 28 is an anode for the thyratron 27, 29 is a thyratron 27 is the cathode of

In this circuit, when the semiconductor switch 4 is off,
The capacitor 3 is connected to the input terminal 1 by the gate trigger pulse DC power supply connected between the input terminal 1 and the ground line.
From, resistor 2, capacitor 3, primary winding 8 of transformer 7,
The charging current flowing in the path of the ground line charges the battery to the polarity shown.

When a positive gate voltage is applied to the gate 5 of the semiconductor switch 4 with respect to the ground line, the switch 4 is turned on and the charge stored in the capacitor 3 is transferred from the illustrated positive pole of the capacitor to the switch 4, The current flows in the direction of the primary winding 8 of the transformer 7 and the negative electrode of the capacitor 3 shown in the figure. For this reason, a pulse voltage corresponding to the winding ratio is induced in the secondary winding 1lIA9 of the transformer 7 with the polarity indicated by the black circle in the figure, and the control voltage of the thyratron 27 is generated via the resistor 41 and capacitor 13.
applied to grid 14. As a result, a certain delay time (
It is called anode lag time. ) after the 8th
As explained in the circuit operation in the figure, the main electrodes of the thyratron 27 break down.

That is, in the circuit of FIG. 6, the gate 5 of the semiconductor switch 4
By controlling the timing of the positive voltage pulse applied to the thyratron 27, the repetition period of the thyratron 27 can be controlled.

Regarding the discharge-pumped laser described above, see, for example, "Current Status of Short Wavelength Laser Technology", Technical Report of the Institute of Electrical Engineers of Japan (Part II)
No. 217 (April 1986), Discharge Characteristics of Copper Vapor Laser, Electric Power Central Research Report 87117 (September 1988), thyratron and its drive circuit, for example, 'Eng11shElectric~alve C
Company Limited, THYRATRON
DATABOOK”, Cornes & Company Limited, 88.2.NS-1500.

Further, in accelerators such as linear induction accelerators used in eye-directed electron lasers, etc., high voltage pulse generation circuits using thyratrons are used in the same way as the method described above. For details, see e.g. D. Birx
, E., Cook, S., Hawkins, S., Poor.

L., Reginato, J., schmidt and.
M, Sm1th: “THEAPPLICAT
ION OF MAGNETIC5WITC,HES
AS Pt1LSESOURCES FORINDUC
TION LINAC5”, IEEE Tran
-saction on Nuclear 5cien
ce, Vol, N5-30. No, 4°pp276
3-2768 (1983).

[Problem that the invention seeks to solve]

Discharge-pumped lasers require stabilization of laser output, low time and
Jitterization is required. For example, a discharge-excited laser (excimer laser, TEMA-
A C○2 laser or a copper vapor laser is used. In order to increase the laser output, multiple laser devices are operated synchronously. In this case, the time jitter of the laser output of each laser device is required to be accurate within several ns.

For example, in a discharge-excited laser with the circuit configuration shown in FIG.
The main cause of the time jitter is the thyratron 27. The time jitter of this thyratron is determined by the performance of the thyratron itself and the thyratron drive circuit used, and in order to reduce the time jitter,
4-pole thyratron (e.g. English Elec
tric Valve Company Limited
manufactured by CX-1625 or LS-411 manufactured by EG&G
It is effective to use a thyratron drive circuit that can raise the gate trigger pulse voltage applied between the control grid and cathode of the thyratron with accurate timing and in as short a time as possible.

In order to obtain such a thyratron drive circuit, for example, as shown in FIG. 6, a transformer 7 with a small leakage inductance (usually obtained by applying toroidal ferrite) is used, and the value of the resistor 41 is minimized. By setting a small value, the rise time of the gate trigger pulse voltage applied to the control grid 14 is accelerated, and the timing of the gate pulse generation circuit applied to the gate 5 of the semiconductor switch 4 is accurately controlled. can get.

However, when the thyratron drive circuit shown in FIG. 6 is used, when the main electrodes of the thyratron 27 break down, there is a gap between the control grid 14 and the cathode 29 of the thyratron as shown in FIG. A surge voltage is induced. This surge voltage V 14 causes a surge current to flow through the control grid 14 , the capacitor 13 , the resistor 41 , the secondary winding 9 of the transformer 7 , and the cathode 29 . This surge current causes transformer 7
A voltage corresponding to the turns ratio of the voltage induced in the secondary winding M9 of the transformer 7 is induced in the primary winding of the transformer 7, and the 17! Applied to the A side. Due to the surge voltage generated due to the breakdown between the main electrodes of the thyratron 27, the peak value of the voltage applied to the primary side of the transformer 7 is determined by the value of the cage inductance and the resistor 41 of the transformer 7. The smaller the value, the higher the value, and in extreme cases, semiconductor switching elements,
This may lead to destruction of the diode 6 or the gate circuit connected to the gate 5 of the semiconductor switch element 4.

That is, when the thyratron drive circuit shown in FIG. It has been difficult to ensure sufficient reliability of the gate circuits used.

Further, as a thyratron drive circuit, for example, as disclosed in Japanese Patent Application Laid-Open No. 1-222669, a semiconductor switch element is used to generate a gate trigger pulse that is applied to the control grid of the thyratron without going through a transformer. There is also a method of improving the voltage rise time, but in this case as well, as explained in the conventional example shown in FIG. 6, the gate applied to the control grid of the thyratron is - If the rise time of the trigger pulse voltage is accelerated, there is a problem that the reliability of the thyratron drive circuit decreases.

In order to solve these problems, thyratrons, which have a high withstand voltage and good switching characteristics, have been used as switching elements in thyratron trigger circuits, but in this case, the lifespan of the thyratron trigger circuits has been reduced. However, there was a problem in that the lifespan of the thyratron used for this was limited.

Note that the above explanation has been about the thyratron drive circuit used for discharge-excited lasers, but in the case of linear induction accelerators, it is necessary to operate more high-voltage pulse generation circuits synchronously, so the above problems can be solved. was more serious.

[Means to solve the problem]

The present invention provides a gas switch gate for a thyratron.
The same gas is supplied through a saturable reactor connected in series with the output end of a high voltage pulse generation circuit consisting of a DC power supply that determines the trigger pulse voltage and a semiconductor switch element that generates the gate trigger pulse voltage. - A gas switch drive circuit characterized in that it is configured so that a gate trigger pulse voltage can be applied to the gate trigger horn of the switch.

In this way, the DC power supply that determines the gate trigger pulse voltage is connected to the output terminal of a high voltage pulse generation circuit consisting of semiconductor switching elements for generating the gate trigger pulse voltage, and the input of the gate trigger of the gas switch. By inserting a saturable reactor in series between the gas and
A high voltage surge can be applied to the gate trigger input of the switch and is blocked by the saturable reactor, which induces a high voltage surge at the gate trigger input of the gas switch when the main electrode of the gas switch is turned on. This is preferable since it is possible to protect the elements constituting the Kate-Lica-pulse generation circuit, including the semiconductor switching element.

In the gas switch drive circuit, the saturable reactor includes a saturable reactor that is generated by a surge voltage applied to the saturable reactor from the gate trigger input terminal side of the gas switch when the gas switch is turned on. If a bias circuit is provided to magnetize the saturable reactor to the opposite polarity, the magnetic flux density of the saturable reactor will change when the gate trigger pulse voltage is applied to the saturable reactor. Since the relative magnetic permeability can be set to a small value when the gas switch This is because the operating magnetic flux density of the saturable reactor can be increased when the high voltage induced at the gate trigger input of the gas switch is applied to the saturable reactor when the electrode is turned on. , it is also possible to downsize the saturable reactor, which is preferable.

In the gas switch drive circuit, the saturable reactor is comprised of a DC power supply that determines the gate trigger pulse voltage of the gas switch, a semiconductor switch element and a transformer for generating the gate trigger pulse voltage. A bias circuit of the saturable reactor is connected in series between one end of the secondary winding of the transformer and a gate trigger input terminal of the gas switch in the high voltage pulse generation circuit. In the case where the transformer also serves as a circuit for biasing the operating magnetic flux density in a direction in which the operating magnetic flux density of the transformer is large, the operating magnetic flux density of the transformer becomes large, and the transformer can be made smaller, which is preferable. .

In the gas switch drive circuit, when a wound core made of an amorphous magnetic alloy ribbon is used as the magnetic core of the saturable reactor, the core exhibits steep saturation characteristics and non-saturation characteristics. Since the relative permeability of the area is also large,
It is possible to obtain a steep gate trigger pulse voltage, and the ability of the saturable reactor to block the voltage induced at the gate trigger input terminal of the gas switch when the gas switch is turned on is also improved. preferable.

In the gas switch drive circuit, the magnetic core of the saturable reactor has a composition: (Fel-6Mm) 10-x-F-m-acu,
S i, B, M.

(Atomic %) (However, M is one or two of Co and Ni, and M' is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti, and Mo. ,a+X
+V+ Z and α are each 0≦a≦0.5.
1≦x≦3. ○≦y≦30゜0≦2≦25, 5≦y+
z≦30.0. 1≦α≦30 is satisfied. ), in which at least 50% of the composition consists of crystals of fine cc Fe solid solution, and the average value of the grain size measured at the largest dimension of each grain is 100 OA or less When the magnetic core is composed of a wound magnetic core using a soft magnetic alloy ribbon, the relative magnetic permeability in the saturation region of the magnetic core is extremely small, so it is possible to obtain a steep gate trigger pulse voltage and to Because the relative magnetic permeability in the saturation region is large and the amount of operating magnetic flux density can be large, a smaller magnetic core can be used to connect the gate trigger input of the gas switch when the gas switch is turned on. This is preferable because the induced voltage can be blocked.

The discharge-excited laser using the gas switch drive circuit described above is preferable because the time jitter of the laser output is significantly reduced.

When two or more of the discharge excitation lasers are operated synchronously, the time jitter of the laser output of each laser is extremely small, so measures are taken to prevent timing deviations of each laser output due to time jitter. This is preferable because it can be done.

Furthermore, the accelerator using the gas switch drive circuit described above is preferable because the time jitter of the accelerating voltage pulse is significantly reduced.

〔Example〕

Examples of the present invention will be described in detail below, but the present invention is not limited to these examples.

(Embodiment 1) FIG. 1 shows an embodiment in which a gas switch drive circuit according to the present invention is applied to a case where a thyratron is used as a gas switch. In this circuit, l is the positive terminal of the DC power input of the gate trigger pulse generation circuit, 2 is the charging resistor of the capacitor 3, 4 is the semiconductor switch element for gate trigger pulse generation, and 5 is the gate of the semiconductor switch element 4. , 6 is a diode, 7 is a transformer, 8 is a primary winding of transformer 7, 9 is a secondary winding of transformer 7, 10 is a saturable reactor, 11 is an output winding of saturable reactor 10, 12 is the bias winding of the saturable reactor 10, 13 is a capacitor for controlling the DC bias current of the control grid of the thyratron 27, 14 is the control grid of the thyratron 27, and 15.16 is the bias winding of the saturable reactor 10. 12 is the winding end of the bias circuit 17, 17 is the bias circuit of the saturable reactor 10, and 18 is the control terminal of the thyratron 27.
A DC bias power supply for the grid 14, 19 a resistor, 20 an inductance for blocking surge power, 21 a varistor, 2
2 is a DC bias power supply for the auxiliary grid 25 of the thyratron 27, 23 is a resistor, 24 is an inductance for blocking surge power, 25 is an auxiliary grid for the thyratron 27, 26
is the ballista, 28 is the anode of thyratron 27, 29
is the cathode of thyratron 27. Further, the bias circuit 9 of the saturable reactor 10 in this circuit was connected to the excimer laser excitation circuit shown in FIG.

Below, the circuit operation of Figure 1 will be explained using the diagram and the saturable reactor unit O.
This will be explained using the operating magnetization curve in FIG.

When the semiconductor switch 4 is off, the gate trigger pulse DC power supply connected between the input terminal 1 and the ground line causes the capacitor 3 to connect the input l4i1 to the resistor 2, the capacitor 3, and the primary of the transformer 7. The charging current flowing through the winding 8 and the ground line charges it to the polarity shown. At this time, the magnetic flux density of the saturable reactor 10 is determined by the bias magnetizing force HB determined by the following formula by the DC bias current flowing from the bias circuit 17 to the bias winding #X12 of the saturable reactor 10 in the direction shown in the figure. , is biased to the saturation region shown at point a in FIG.

l.

N12: Number of turns of the bias winding 12 of the saturable reactor 10 B: Bias current (A) ■,: Average magnetic path length of the saturable reactor 10 (m) When a gate voltage in the direction is applied, the switch 4 turns on, and the charge accumulated in the capacitor 3 is transferred from the positive terminal of the capacitor to the switch 4, the primary winding 8 of the transformer 7, and the negative terminal of the capacitor 3. flows in the direction of Therefore, a pulse voltage input according to the turns ratio is induced in the secondary winding 9 of the transformer 7 with the polarity indicated by the black circle in the figure, and the saturable reactor 10
is applied to the output number of turns 11. As a result, the magnetic flux density of the reactor 10 changes from point a to point b in FIG. 2, but the relative magnetic permeability during this period is extremely small because it is in the saturation region, and the output winding ItiAll of the reactor 10 changes at the pulse voltage. There is almost no stopping it. As a result, a gate trigger pulse voltage with a steep rise can be applied to the control grid 14 of the thyratron 27, and after a certain delay time, the voltage between the main electrodes of the thyratron 27 breaks down at 1=0. .

A surge voltage 'V 14 with the control grid 14 as the positive terminal is induced between the main electrodes of the thyratron 27 until t=7, and the voltage is applied to the saturable reactor 1 via the capacitor 13.
0 output winding ill.

Therefore, the magnetic flux density of the saturable reactor 10 changes by ΔB from point b in FIG. 2, via point 87 and point C, to point d in the period from 1=0 to τ. Since the relative magnetic permeability between point C and point d is extremely large, most of the surge voltage V14 is blocked by the output winding 11 of the saturable reactor 10 and is not applied to the secondary winding 9 of the transformer 7. The voltage applied is controlled to an extremely small value. Therefore, the voltage induced on the primary side of the transformer 7 can also be controlled, and the semiconductor switch element, the diode 6, the gate circuit of the semiconductor switch element, etc. can be protected. In the above operation, the following equation holds true.

N1. : Number of turns Ae of the output turns gx1 of the saturable reactor 10 : Effective cross-sectional area of the magnetic core of the saturable reactor 10 (m2
) ΔB=operating magnetic flux density amount (T) of the saturable reactor 10 When t=τ1 is reached, the magnetic flux density of the saturable reactor 11 is changed from the bias circuit 17 to the saturable reactor 1
The bias magnetizing force HD generated by the bias voltage IB applied to the zero bias winding 12 changes from point d to point a in FIG.

By repeating the above-described operations, the gate trigger circuit can be protected without delaying the rise time of the gate trigger pulse voltage applied to the control grid 14 of the thyratron 27.

As is clear from the above operating principle, the saturable reactor 10 is required to have the following characteristics.

1) In order to increase the rise time of the gate trigger pulse voltage applied to the control grid 14 of the thyratron 27 as much as possible, the inductance L1°fsatl in the saturation region of the saturable reactor IO should be as small as possible.

2) In order to protect the gate trigger circuit of the thyratron 27, the inductance LlO (una@t) in the non-saturable region of the saturable reactor 10 should be as large as possible.

3) The time jitter caused by the saturable reactor 10 is small in order to reduce the time jitter of the gate trigger pulse voltage applied to the control grid 14 of the thyratron 27.

Therefore, from the point of 1), the magnetic core constituting the saturable reactor 10 should have a small relative magnetic permeability μγiamb) in the saturation region and a large operating magnetic flux density ΔB.

In view of 2), the relative magnetic permeability μγ1aatl in the non-saturated region is large.

From the point of 3), regarding magnetic core fluctuation noise (magnetic core fluctuation noise), for example, see Murakami-author 2 "Magnetic Applied Engineering",
P34fil, described in Breakfast Shoten (i984). ) is small.

is necessary.

In the embodiment of the present invention shown in FIG. 1, the magnetic core of the saturable reactor 10 has the composition, DC magnetic characteristics, saturation magnetostriction, and shape shown in Table 2 as shown in Table 1, and the output of the reactor 10 is Table 3 shows a comparison between the conventional example shown in FIG. 6 and the case where both the winding [11 and the bias winding fi12 are one turn]. In Table 3, ΔB is the amount of operating magnetic flux density at which the magnetic core of the reactor is operated by the surge voltage applied to the output winding ill of the saturable reactor 10 after breakdown between the main electrodes of the thyratron 27; is the bias current flowing through the bias winding 12 of the reactor, and I tp is the surge voltage generated when the main current of the thyratron breaks down, which is caused by the surge voltage flowing from the control grid 14 of the thyratron to the transformer via the capacitor 13. The surge current peak value, t, flowing into the 2pA winding iI9 of 7 is the gate trigger voltage applied to the control grid of the thyratron.
The rise time of the pulse voltage, Δt, is the thyratron 27
Time table for switching operation between main electrodes - Samples Nos. 1 to 9 are amorphous alloys with interlayer insulation with a 7.5U4 polyimide film, Nos. 10-14 are ultrafine crystalline alloys , with interlayer insulation of Sin.

** B 800 is the magnetic flux density at a magnetizing force of 800^8, and λS is the saturation magnetostriction.

No. 2 table No. table The umbrella repetition frequency is 100Hz in both cases.

・It is jitter. As the high voltage pulse generating circuit, an excimer laser shown in FIG. 8 was used. In the present invention, the dimensions of the magnetic core of the saturable reactor 10 shown in Table 2 and the bias current shown in Table 3 are as shown in the conceptual diagram of the B-H loop of the same core shown in FIG. The voltage is selected so that it will not be saturated by the surge voltage applied to the output winding ill of the saturable reactor 10 after the breakdown occurs between the main electrodes of the saturable reactor 10.

Conventional Example 1 is a case where the resistor 41 is short-terminated in the circuit shown in FIG. The semiconductor switch element 4 and diode 6 of the gate trigger circuit shown in the figure were destroyed.

Furthermore, in Conventional Example 2, a resistor 41 is inserted in the figure, and in this example, the surge current peak value 1° can be made small, and safe operation of the gate/trigger circuit can be achieved. 27 control grids 14
As the rise time of the gate trigger pulse voltage applied to the thyratron became significantly longer, the time-jitter Δ during simultaneous switching between the main electrodes of the thyratron also became large.

On the other hand, according to the present invention, the surge current generated after the breakdown between the main electrodes of the thyratron 27 can be reduced without significantly slowing down the rise time of the gate trigger pulse voltage applied to the control grid 14 of the thyratron 27. Since the peak value I tp can be suppressed, the switching operation time between the main electrodes of the thyratron 27 can be reduced while ensuring safe operation of the gate trigger circuit.
Thick Δt can be reduced.

As can be seen from Table 3, the magnetic core of the saturable reactor 1o is constructed using an amorphous magnetic ribbon or an iron-based ultrafine-crystalline magnetic ribbon, rather than Ni-Zn ferrite or the like. In this case, it is possible to reduce the time jitter Δt in the switching operation between the main electrodes of the thyratron 27 while ensuring safe operation of the gate trigger circuit. When using a magnetic core of 100%, it was easy to reduce the size of the magnetic core, and excellent performance could be achieved with just one small bias current.

(Embodiment 2) FIG. 3 shows another embodiment in which the gas switch drive circuit according to the present invention is applied to a case where a thyratron is used as the gas switch. In this circuit, the bias winding 9 of the saturable reactor 10 is
12 is also passed through the secondary winding of the transformer 7, so that the operating magnetic flux density ΔB' of the transformer can be increased, thereby making the transformer more compact and having lower leakage and inductance. It has characteristics in the intended place,
In other respects, the same effects as in Example 1 can be obtained.

In FIG. 3, reference numeral 35 indicates a voltage pulse induced in the second ground winding of the transformer 7 when the semiconductor switch element 4 of the gate trigger circuit is turned on is applied to the bias winding 12 of the saturable reactor 10. In addition to preventing the bias winding of the saturable reactor 10 due to breakdown between the main electrodes of the thyratron 27! ! This is an inductance for suppressing the voltage induced in the transformer 12 from being applied to the secondary winding of the transformer 7.

FIG. 4 shows a conceptual diagram of the operating magnetization curve of the transformer 7 in FIG. 3 of this embodiment, and shows the saturable reactor 10
Pole making 15 at the output end of the bias circuit 17, 2 of the transformer 7
Next winding 9, inductance 35, saturable reactor 10
The magnetic flux density of the transformer 7 is opposite to the black circle shown in the figure due to the magnetizing force Ha' as shown by the ground rent caused by the bias current In flowing in the path of the secondary winding 12 and the non-pole 6 at the output end of the bias circuit 17. The polarity is biased to point a'.

N, : Number of turns of secondary winding ft1i19 of transformer 7 1,'
: Average magnetic path length of transformer 7 (m) Next, when the semiconductor switch element is turned on, a voltage is applied to the primary winding IJI8 of the transformer 7 with the polarity indicated by the black circle in the figure. As a result, the magnetic flux density of the transformer 7 is Δ from point a' to point b' in FIG.
B' can be varied and can be made larger than the operating magnetic flux density amount of the transformer of FIG. Incidentally, the magnetic core used for the magnetic core of the transformer 7 of this embodiment is ΔB'
It is effective to use materials such as those shown in Samples 1 to 14 in Table 1 shown in Example 1 above in order to increase the size of the material.

〔Effect of the invention〕

As described above, according to the present invention, as a gas switch drive circuit using a semiconductor switch element used in a high voltage pulse generation circuit using a gas switch such as a thyratron, the reliability is extremely high. It is possible to obtain a switching operation between the main electrodes with less time jitter.

Furthermore, in this embodiment, the effects of improving reliability and reducing output time jitter by using the present gas switch drive circuit using an excimer laser as an example have been mainly described. It goes without saying that similar effects can be obtained with other discharge-excited lasers, linear induction accelerators, etc. that use switch drive circuits.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the gas switch drive circuit according to the present invention, and FIG. 2 is a conceptual diagram of the operating magnetization curve of the saturable reactor used in the gas switch drive circuit of the present invention.
FIG. 3 is a diagram showing another embodiment of the gas switch drive circuit according to the present invention, FIG. 4 is a conceptual diagram of the operating magnetization curve of the transformer 7 in FIG. 3, and FIG. 3 is a circuit configuration diagram showing an example of the bias circuit of the saturable reactor, FIG. 6 is a diagram showing a conventional gas switch drive circuit,
FIG. 7 is a diagram showing an example of a surge voltage waveform induced between the control grid 14 and the cathode 29 of the thyratron, and FIG. 8 is a diagram showing the main circuit configuration of the excimer laser. 1: DC power supply input positive end, 4: Semiconductor switch element 6:
Diode, 7: Transformer, 10: Saturable reactor, 1
2: Bias winding of saturable reactor 10, 14 nicontrol grid, 17: Bias circuit of saturable reactor 10, 25: Auxiliary grid, 27: Thyratron, 28: Anode of thyratron 27, 29: Anode of thyratron 27 Cathode 41: Resistance diagram

Claims (1)

[Claims] 1) An output terminal of a high voltage pulse generation circuit consisting of a DC power supply that determines the gate trigger pulse voltage of a gas switch and a semiconductor switch element for generating the gate trigger pulse voltage. A gas switch drive circuit characterized in that it is configured to be able to apply a gate trigger pulse voltage to a gate trigger input of the gas switch via a saturable reactor connected in series with the gas switch. 2) The gas switch drive circuit according to claim 1,
The saturable reactor has a polarity opposite to that in which the saturable reactor is magnetized by a surge voltage applied to the saturable reactor from the gate trigger input terminal side of the gas switch when the gas switch is turned on. A gas switch drive circuit characterized in that a bias circuit for magnetizing is provided. 3) The gas switch drive circuit according to claim 2, wherein the saturable reactor is connected to the gate of the gas switch.
One end of the secondary winding of the transformer in a high voltage pulse generation circuit comprising a DC power source that determines the trigger pulse voltage, a semiconductor switching element for generating the gate trigger pulse voltage, and a transformer. It is connected in series between the gate and trigger input terminals of the gas switch, and the bias circuit of the saturable reactor also serves as a circuit for biasing the transformer in a direction that can increase the amount of operating magnetic flux density. A gas switch drive circuit characterized by: 4) The gas switch drive circuit according to any one of claims 1 to 3, wherein the magnetic core of the saturable reactor is a wound magnetic core constructed using an amorphous magnetic alloy ribbon. Gas switch drive circuit. 5) In the gas switch drive circuit according to any one of claims 1 to 3, the composition of the magnetic core of the saturable reactor is (Fe_1_-_aM_a)_1_0_0_-_x_-
_y_-_z_αCu_xSi_yB_zM_α (atomic %) (However, M is one or two types of Co and Ni,
M' is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti and Mo, a, x, y
, z and α are respectively 0≦a≦0.5, 0.1≦x≦3, 0≦y≦30, 0≦
z≦25, 5≦y+z≦30, and 0.1≦α≦30. ), in which at least 50% of the composition consists of fine bccFe solid solution grains, and the average grain size measured at the largest dimension of each grain is 1000 Å or less. A gas switch drive circuit characterized by being constructed of a wound magnetic core using a soft magnetic alloy ribbon. 6) A discharge-excited laser using the gas switch drive circuit according to any one of claims 1 to 5. 7) A discharge-excited laser, characterized in that two or more discharge-excited lasers according to claim 6 are configured to operate synchronously. 8) An accelerator using the gas switch drive circuit according to any one of claims 1 to 5.