JP2738077B2 - Discharge type pulse laser device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a discharge type pulse laser device.

[Conventional technology]

Figure 5 shows an example of a magazine (Japanese Journal of Applied
Physics Vol.24 No11.PP.855) is a circuit configuration diagram of a discharge excitation circuit of a conventional discharge-type pulse laser device using a saturable reactor. In the figure, (1) is a saturable reactor composed of a plurality of unit cores,
(2) is a saturable reactor bias power supply, (3) is a saturable reactor bias circuit switch, (4) is a first main electrode, (5) is a second main electrode, and (6) is for preionization. The auxiliary electrode of (7) is a peaking capacitor,
(8) is a storage capacitor, (9) is a laser excitation circuit switch, and (10) is an inductance for charging the storage capacitor.

Next, the operation will be described. FIG. 6 shows an example of a BH characteristic curve of a magnetic material used in the conventional saturable reactor (1). Points B _S1 and B _S2 are the residual magnetic flux densities when a bias voltage is applied to the saturable reactor, respectively.
B ₁ and ΔB ₂ are determined respectively. Here, assuming that the core cross-sectional area of the saturable reactor is S, the saturation magnetic flux Φ _S = ΔB · S
When the time integration of the applied voltage V reaches Φ _S at time t ₁ (∫ ₀ ^{t 1} V · dt = Φ _S ), the saturable reactor is saturated.

In FIG. 5, the electric charge stored in the storage capacitor (8) by the high voltage power supply starts to transfer to the peaking capacitor (7) by turning on the laser excitation circuit switch (9). On the other hand, saturable reactor (1)
Is an unsaturated state at first, and only a small leakage current flows through the saturable reactor (1). Eventually time integral and reaches [Phi _S saturable reactor voltage V applied to the saturable reactor (1) is saturated, the main discharge electrodes (4),
During (5), a large current flows to excite the laser medium.

The switching characteristics of the saturable reactor largely depend on the BH characteristic curve of the magnetic material used for the core material. In order to improve the switching characteristics, it is necessary that the magnetic flux can be changed from an unsaturated state to a saturated state with a small magnetomotive force. Therefore, a magnetic flux having a square BH characteristic curve as shown in FIG. It is desirable to use.

[Problems to be solved by the invention]

Excitation circuit of a conventional discharge type pulse laser apparatus is constructed as described above, in the case of change of voltage applied to the excitation circuit is necessary to adjust the saturation magnetic flux [Phi _S of the saturable reactor occurs. At this time, when a magnetic material having a BH characteristic curve as shown in FIG. 6 is used for the saturable reactor, the operating region of the saturable reactor is adjusted to ΔB ₁ , ΔB ₁ by adjusting the applied bias voltage. if changes as _2, can adjust the saturation magnetic flux [Phi _S of the saturable reactor,
The range is limited to a region where ΔB greatly changes by adjusting the bias voltage. When a magnetic material having a square BH characteristic curve is used as shown in FIG.
Because operating region ΔB of applying the saturable reactor be varied bias voltage is as that shown in FIG. 6, which does not change significantly, it was not possible to adjust the saturation magnetic flux [Phi _S of the saturable reactor. Therefore, in order to operate the saturable reactor at a different laser excitation voltage, the saturable reactor had to be replaced with a reactor suitable for the voltage.

The present invention has been made in order to reduce the above problems, and to provide a discharge type pulse laser device capable of changing a saturation point and an inductance of a saturable reactor without replacing the saturable reactor. With the goal.

[Means for solving the problem]

The discharge pulse laser device according to the present invention includes a saturable reactor between a main electrode and a capacitor adjacent to the main electrode, the saturable reactor includes a plurality of unit cores, and a bias power supply for each unit core. And a bias circuit switch for selecting a unit core.

[Action]

The discharge type pulse laser device according to the present invention can select and reset some of the unit cores constituting the saturable reactor to change the saturation point and the inductance of the saturable reactor.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, (11) is a first unit core constituting the saturable reactor (1), (12) is a bias circuit switch for resetting the unit core (11), (13)
Is a bias circuit power supply for setting the residual magnetic flux density of the unit core (11), (14) is a second unit core constituting the saturable reactor (1), and (15) is a reset of the unit core (14). Bias circuit switch, (16)
Is also the bias circuit power supply for the unit core (14),
(17) is an n-th unit core constituting the saturable reactor (1), (18) is a bias circuit switch for resetting the unit core (17), and (19) is similarly a bias of the unit core (17). Circuit power supply.

Next, the operation will be described. Saturable reactor (1)
Each of the unit cores (11), (14), and (17) that constitute the above has a separate bias circuit, so that only an appropriate number of the bias circuit switches (12), (15), and (18) Is turned on, only some of the unit cores can be reset by some of the bias circuits. Thereby increase or decrease the number of the bias circuit switch that turned ON, the operation region ΔB saturable reactors, it is possible to control the saturation magnetic flux [Phi _S.

FIG. 2 is an example of saturable reactor switching characteristics when the configuration of the above embodiment is used. The horizontal axis represents time, and the vertical axis represents voltage. The bias circuit of all n units core constituting the saturable reactor when used in reset, ∫ time t _{n 0} ^tn Vdt = Φ _S becomes,
The saturable reactor is saturated and switches. In the bias circuit is a conventional configuration of the saturable reactor, if it can not control the saturation magnetic flux [Phi _S of the core, it was not possible to switch the saturable reactor at a time other than t _n.
On the other hand, when the configuration of the present invention is used, the number of unit cores reset by the bias circuit is changed from n to n-1, n-2,. Since the density Φ _S can be controlled, the switching time of the saturable reactor is correspondingly changed to t _n , t
_{n-1, t n-2} ... in can be varied _{as, V n, V n-1} , V n-2 ... and can vary depending charging voltage thereto. That is, the first
In the figure, _assuming that the saturation magnetic flux densities of the unit cores (11), (14) and (17) are Φ ₁ , Φ ₂ and Φ _n respectively, the switch (12)
(15) When (18) is all ON, as described above, the saturation magnetic flux density is Φ _S (Φ _S = Φ ₁ + Φ ₂ + Φ _n ), and the switching time is t _{n and the} charging voltage is V _n . Switch (18)
The turned _{OFF, Φ S = Φ 1 + Φ} 2 , and the switching time ∫ ₀ ^t2 Vdt = Φ _S become time t ₂ (charging voltage V ₂₎ to vary (see FIG. 2). Similarly, switch (1
5) OFF Then the, Φ _{S =} Φ _1, and the switching time t ₁ (charging voltage changes to V _1).

FIG. 3 shows another example of saturable reactor switching characteristics when the configuration of the present invention is used. The horizontal axis represents time, and the vertical axis represents voltage. Now, the charging voltage of the peaking capacitor (7) and is V _a, the saturation magnetic flux [Phi _S of the saturable reactor voltage applied to the saturable reactor
Is set as Φ _{S =} ∫ ₀ ^ta Vdt to saturate at time t _a which becomes V _a (curve A). Here if you want the charging voltage of the peaking capacitor (7) is operated in the V _b (curve B), if it can not control the saturation magnetic flux [Phi _S of the core in the conventional arrangement, the saturable reactor is Φ _{S =} ∫ ₀ thereby switching at voltage V _c (<V _b) at time t _c as a ^tc Vdt. For this reason, the energy transmission efficiency between the peaking capacitor (7) and the main electrodes (4) and (5) is reduced.
On the other hand, when the configuration of the present invention is used, the saturation magnetic flux of the saturable reactor can be changed by changing the number of unit cores to be reset by the bias circuit. So [Phi _S is set to _'= ∫ ₀ ^tb Vdt become so by selecting the unit core core to reset saturation magnetic flux [Phi _S', the saturable reactor at time t _b the voltage applied to the saturable reactor is V _b Can be switched. By using the configuration of the present invention, the peaking capacitor (7)
Energy transfer efficiency between the main electrode (4) and (5)
Can be kept at 100%.

In the above embodiment, a bias power supply is prepared for each bias circuit of each unit core constituting the saturable reactor. However, as shown in FIG. 4, the bias power supply is one variable voltage source (20), and Switch (12), (1
The saturation operation point and inductance of the saturable reactor (1) may be adjusted only by ON / OFF of (5) and (18) and the voltage adjustment of the variable voltage source (20).

Further, in the above embodiment, the laser pumping circuit is of the capacitance transfer type. However, the laser pumping circuit may be of another pumping circuit type such as a PFN (Pulse Forming Network) system in which the capacitor portion has a distributed constant. The same effect as the example is achieved.

〔The invention's effect〕

As described above, according to the present invention, the saturable reactor is provided between the main electrode and the capacitor adjacent to the main electrode,
Since the saturable reactor includes a plurality of unit cores, and a bias power supply and a bias circuit switch for unit core selection for each unit core, the saturation point and inductance of the saturable reactor can be easily changed, There is an effect that controllability can be provided so that the saturable reactor operates at the optimum saturation operation point according to the applied voltage.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a discharge excitation circuit of a discharge type pulse laser device according to an embodiment of the present invention, and FIGS. 2 and 3 are switching characteristics of a saturable reactor according to an embodiment of the present invention. FIG. 4 is a circuit diagram showing a discharge excitation circuit of a discharge type pulse laser device according to another embodiment of the present invention, and FIG. 5 is a circuit showing a discharge excitation circuit of a conventional discharge type pulse laser device. Configuration diagram and 6th
FIG. 7 and FIG. 7 are characteristic diagrams showing BH characteristics of the magnetic material used for the saturable reactor. In the figure, (1) is a saturable reactor, (11) and (14)
(17) is a unit core, (12) (15) (18) are bias circuit switches, (13) (16) (19) are bias power supplies,
(20) is a variable voltage source. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] A saturable reactor is provided between a main electrode and a capacitor adjacent to the main electrode. The saturable reactor includes a plurality of unit cores, a bias power supply for each unit core, and a bias for selecting a unit core. A discharge-type pulse laser device including a circuit switch.