JPH02116184A - Pulse laser power source device - Google Patents

Abstract

PURPOSE:To improve efficiency of energy transfer of each stage by connecting a reactor which can charge a value of inductance between a capacitor at a magnetic pulse compression circuit and a pulse transformer connected to a charge power source. CONSTITUTION:Electric charge stored in capacitors 8, 9, 10 of a charge power source 1 is charged to a capacitor 16 of a first stage of a magnetic compression circuit through a pulse transformer 11 and a reactor 23 equipped with a tap at a specified frequency. A voltage rises to the capacitor 16 at the frequency. When it attains a saturated voltage of a saturable reactor 19 of the first stage, electric charge is transferred to a capacitor 17 of the next stage through a reactor 24 equipped with a tap and the reactor 19. Similarly, electric charge is transferred to a capacitor 18 of a third stage through a reactor 25 equipped with a tap and a saturable reactor 20. Since a saturated voltage thereby becomes a maximum value of an input voltage, efficiency of energy transfer of each stage is improve.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a pulsed laser power supply device for realizing a large current pulsed laser power supply.

(Prior art) In recent years, various lasers have been considered for industrial use, including TEA and TEMA CO2 lasers used in uranium separation equipment using molecular methods, excimer lasers, and copper vapor lasers. There is an increasing demand for superior high-current, repetitive-pulse laser power sources for these lasers. In addition, a similar power source is used for the accelerator Fast Pu1s
ed) is also required for lagnets.

Such a large current/repetitive pulse power supply requires a fast current rise (100 KA/μ5 ec) and high repeatability (200 KA/μ5 ec).
l0KPPS), large current (~l0KA), high voltage (
~150KV), a saturable reactor with a low impedance and high reactance ratio (1112 or higher), which responds satisfactorily with 1112 or more, and has a large inductance ratio between saturation and non-saturation), a very narrow pulse width (10
0nSeC), jitter time (several tens of nanoseconds or less), long life (about 108 to 11 or more), and other conditions are required.

The electric circuit shown in FIG. 2 was devised for the above purpose. In the electric circuit shown in FIG. 2, the low voltage side of the pulse transformer 11 is a switch circuit for generating a repetitive pulse current, and the high voltage side is a magnetic pulse compression circuit (Magnetic pulse compression circuit).
tic Pulse Compression=MPC
It is an electrical circuit called a circuit.

In the switch circuit formed on the low voltage side of the pulse transformer 11 shown in FIG.
, 3.4 and the capacitor 8, via the rectifier 5, 6.7.
9 and 10 are connected, and three are connected in parallel to the low voltage side of the pulse transformer 11. Further, the thyristors 12, 13, and 14, which are switch elements, are turned on by the driver 15.

The operation of such a switch circuit is as follows: First, the charging power supply 1
Accordingly, the charging reactor 2, 3.4 and the rectifier 5,
6.7, the capacitor 8°9.10 is always charged to a constant voltage. Here, the driver 15 fires the thyristors 12, 13, 14 one after another so that the frequency required for the entire power supply is reached, and the low voltage side of the pulse transformer 11 is activated at the required number of repetitions. A pulse current is generated.

In the example shown in Figure 2, the number of thyristors is three (that is, the circuit connected to the low voltage side of the pulse transformer is three in parallel), but this is due to the number of repeated pulses required as a power source and the number of thyristors. Choose an appropriate number depending on your ability. For example, a general thyristor has a frequency of several hundred Hz, l kll
The limit is that it can be used at a repetition frequency of about z. Therefore, for example, when the repetition frequency is 5 kHz, the number of thyristors in parallel is 7 to 10 or more.

In addition, in Fig. 2, the switching element for generating a repetitive pulse current is not limited to a thyristor, but a mechanical switch is used as the switching element under the severe conditions described above. However, there is a problem in terms of lifespan, and in the end, thyristors are the most suitable.

The switch element used in such a switch circuit plays the role of transmitting energy from the charging power source 1 to the MPC circuit side with a constant pulse width, and a thyratron or a semiconductor is considered to be optimal for this switch element. In the above-mentioned high voltage power supply circuit, the responsibility of the switch is large, and a correspondingly large switch must be used.

On the other hand, the MPC circuit on the high voltage side of the pulse transformer 11 is composed of capacitors 1B and 17.18 of appropriate values and saturable reactors 19, 20, and 21 in three stages. The time width of the current input from the low voltage side of the device 11 is sequentially compressed. With this configuration, by reducing the time width of the current input from the low voltage side of the pulse transformer to about 1/100, the rate of increase in current can be increased to the above-mentioned 100 kA/μsec or more.

To describe the operation of the high voltage side of the pulse transformer 11 in detail, when voltage is generated on the high voltage side of the pulse transformer 11,
The interelectrode voltage of the first stage capacitor 16 increases in proportion to this voltage. As a result, a small amount of current flows into the first stage saturable reactor 19 in proportion to the voltage between the poles of the capacitor 16, but when this current reaches a certain value, the number of magnetic fluxes in the iron core of the saturable reactor 19 becomes saturated. When the magnetic flux density exceeds the saturable reactor 19, the saturable reactor 19 becomes saturated, the inductance rapidly decreases, and the energy stored in the capacitor 16 is transferred to the second stage capacitor 17 via the saturable reactor 19. In this case, the saturable reactor l of each stage
By successively reducing the inductance of the Hell 19, 20, 21 during non-saturation and saturation, the frequency of the current flowing through each stage can be made higher in sequence.

By the way, the relationship between the first-stage capacitor 16, the first-stage saturable reactor 19, and the second-stage capacitor 17 is such that when the saturable reactors 1 to 19 are non-saturated, the current flowing through this loop is First stage capacitor 1 at frequency
6, impedance, and first stage saturable reactor 1
By setting the impedance of 9 to an appropriate value when unsaturated, the timing at which energy is transferred from the first stage capacitor 16 to the second stage capacitor 17 can be adjusted, and when the saturable reactor 19 is saturated, By making the impedance of the saturable reactor 19 at saturation sufficiently larger than the impedance of the second stage capacitor 17 at the current frequency at which the saturable reactor 19 is saturated, the first stage capacitor 16
Almost all of the energy can be transferred to the capacitor 17.

As mentioned above, there are many specific combinations of capacitors and saturable reactors that can be considered to adjust the timing of energy transfer through impedance relationships and improve the efficiency of energy transfer. This is a method of keeping the value constant and changing the value of the saturable reactor.

The characteristic equation of the saturable reactor is: The saturation voltage oc of the saturable reactor (square of the input frequency XLt line x saturation magnetic flux density of the iron core x cross-sectional area of the iron core). As mentioned above, it is not easy to adjust the timing of energy transfer and change the value of the saturable reactor by changing the number of turns of the iron core or winding in order to improve the efficiency of the Kirgyi transfer. It's not something that can be done.

(Problem to be solved by the invention) Regarding the conventional pulsed laser power supply as described above, the voltage value at which the magnetic compression circuit operates (referring to the saturable reactor or the value when the saturation voltage is reached) is the same as that of the saturable reactor. Because it was determined by the configuration, it was not possible to improve the efficiency of energy transfer. Furthermore, the saturation voltage value must be changed depending on the configuration of the laser discharge section serving as the load, but it was not easy to change the saturation voltage of the saturable reactor, so the saturation voltage value could not be changed. Furthermore, the same thing can be said when it is desired to adjust the input while keeping the operating voltage constant using the same discharge section.

Therefore, the present invention was proposed to eliminate the above-mentioned drawbacks, and its purpose is to easily change the saturation voltage value of the saturable reactor, improve the efficiency of energy transfer in each stage, and enable input adjustment. The purpose of the present invention is to provide a pulsed laser power supply device.

[Structure of the invention]

(Means for Solving the Problems) The pulse laser power supply device of the present invention includes a reactor for adjusting the circuit frequency between the capacitor of the charging power supply and the capacitor of the first stage of the magnetic compression circuit, and a saturable reactor of each stage. By providing a circuit frequency adjusting reactor in series, the input frequency of the magnetic compression circuit can be adjusted, and the saturation voltage value of the saturable reactor can also be adjusted.

(Function) According to the present invention having the above configuration, the saturation voltage value of each saturable reactor of the magnetic compression circuit can be adjusted to an optimal value, and the efficiency of energy transfer in each stage can be improved. becomes possible.

(Example) An example of the present invention will be described below in detail based on FIG. Note that the description of the same parts as the conventional type shown in FIG. 2 will be omitted.

In this embodiment, as shown in the circuit diagram of FIG.
A tapped glue handle 23 is provided between the pulse transformer 11 and the first stage capacitor 16 of the magnetic compression circuit. The charge stored in the capacitor 8°9.10 of the charging power source 1 is charged at a certain frequency to the first stage capacitor 16 of the magnetic compression circuit via the pulse transformer 11 and the tapped handle 23. When the voltage rises in the first stage capacitor 16 of the magnetic compression circuit at that frequency and reaches the saturation voltage of the first stage saturable reactor 19, it passes through the tapped axle 24 and the saturable reactor 19 to the next stage capacitor. Transfer the charge to 17. Similarly, charge is transferred to the third stage capacitor 18 via the tapped axle 25 and the saturable reactor 20. Finally, charges are input to the discharge section 22 via the saturable reactor 21.

In the pulse laser power supply device of this embodiment having such a configuration, the saturable reactor shown in FIG. 19.2
If the saturation voltage of 0.21 is not the maximum value of the input voltage,
By changing the value of the circuit frequency adjustment reactor 23.24゜25, the value of the circuit frequency input to each stage is changed, the saturation voltage value of the saturable reactor 19, 20.21 is adjusted, and the input voltage waveform is changed. It is possible to reach the saturation voltage at the maximum value. Since the saturation voltage becomes the maximum value of the input voltage, the efficiency of energy transfer in each stage is improved.

〔Effect of the invention〕

In this way, when the pulse laser power supply device of this embodiment is used, the saturation voltage value of the saturable reactor at each stage of the magnetic compression circuit can be finely adjusted to the maximum value of the input voltage value, thereby increasing the efficiency of energy transfer at each stage. can be improved. As described above, the operation of the magnetic compression circuit can be performed in an optimal state, and a pulse laser power supply device with good overall efficiency can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing one embodiment of a pulse laser power supply device of the present invention, and FIG. 2 is a circuit diagram showing an example of a conventional pulse laser power supply device. 1... Charging power supply, 8.9.10... Capacitor, 12, 13.14... Switch element (thyristor)
, 15... Driver, 11... Pulse transformer, 1B, 17.18... Capacitor, 19, 20.
21...Saturable reactor, 22...Laser discharge section, 23, 24.25...Tapped axle. Agent Patent Attorney Noriyuki Chika Yudo Ken Daishimaru

Claims (1)

[Claims] In a pulse laser power supply device having a switch circuit in which a switch element is connected to a capacitor connected to a charging power supply, and a magnetic pulse compression circuit in which a saturable reactor and a capacitor are connected to a laser discharge section, the capacitor in the magnetic pulse compression circuit and A pulse laser power supply device characterized in that a reactor capable of varying the value of inductance is connected between a pulse transformer connected to a charging power source.