JPH04326808A - Pulse generator - Google Patents

Abstract

PURPOSE:To supply a high-voltage, rectangular wave pulse having a sharp rise characteristic, short pulse width and gentle fluctuation of its pulse height value. CONSTITUTION:A bloom line 7 and a saturatable reactle 8 are connected to a charging power source 1, a load 5 is connected to this bloom line 7 and therefore, the pulse generator is constituted to generate the rectangular wave pulse at the load 5. The charging power source 1 and the input side terminal of the coaxial bloom line 7 are connected through a variable inductance 10. By changing the size of the variable inductance 10, an output waveform is adjusted and the fluctuation of the waveheight value is suppressed.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse generator for supplying high-voltage rectangular wave pulses to electron guns, klystrons, and the like.

0003

2. Description of the Related Art Conventionally, a rectangular wave pulse generator that combines a capacitance element, an inductance element, and a thyratron has often been used as a high voltage pulse generator. FIG. 2 is an example of a rectangular wave pulse generator using a thyratron. In this device, a rectangular wave pulse can be generated in a load 5 by charging a pulse generating circuit 2 to a constant voltage using a charging power source 1 and then turning on a thyratron 3.

In this case, the withstand voltage of the thyratron 3 is usually several tens of kV, and if a higher voltage is to be generated, a pulse transformer 4 is used to boost the voltage as shown in FIG. When using the pulse forming circuit 2, the impedance of the circuit needs to be equal to the impedance of the load 5, and the output voltage is 1/1 of the charging voltage on the temporary side of the pulse transformer.
It becomes 2.

In order to increase the output voltage to a high voltage, there is a method other than using a pulse transformer, in which pulse forming lines such as Blumlein type and stack line type are connected in series. FIG. 3 shows a rectangular wave pulse generator using Blumlein 6, and this device uses thyratron 3 as a switching element. When such a Blumlein is used, the surge impedance between the first conductor 61 and the second conductor 62 is Z1, and the surge impedance between the second conductor 62 and the third conductor 63 is Z2.
and when the impedance of load 5 is R, R/2
If =Z1 =Z2, a rectangular wave pulse with a voltage equal to the charging voltage is obtained as the output.

Furthermore, if an output voltage exceeding the withstand voltage of the thyratron is required, the switching element shown in FIG.
Instead of the thyratron, a method of using a magnetic switch that takes advantage of the nonlinearity of the inductance of a saturable reactor is also being considered. In this method, by increasing the core cross-sectional area according to the desired voltage, the saturation voltage of the saturable reactor can be increased, so switching at high voltage is possible.

[0007]

[Problems to be Solved by the Invention] In recent years, in particle acceleration power sources used in free electron lasers and particle acceleration devices using high frequency waves such as klystrons, in order to increase particle acceleration efficiency, fluctuations in the peak value have been reduced by 1. %, and the quality of the rectangular wave pulse has become a problem.

At the same time, the accelerating voltage of the particle beam is becoming higher and higher, and accordingly, the voltage of the pulse power source is also becoming higher, and a large voltage is being applied to the accelerating section. In such a situation, in order to prevent dielectric breakdown in the accelerating section, a pulse with an extremely short width and a steep rise is required.

Therefore, in the conventional technology shown in FIG. 2, the inductance value of the inductance element constituting the pulse forming line 2 is made variable, and by adjusting this, fluctuations in the peak value are reduced, and a high-quality rectangular wave is produced. Attempts are being made to obtain However, in this conventional technique, since the pulse forming line is constructed using lumped constant elements, there are limitations on the steepness of the rise and the pulse width, and the above-mentioned problem could not be satisfied.

Furthermore, although the conventional technology using the Blumlein line shown in FIG. 3 is suitable for high-voltage equipment, it is difficult to adjust the constants of the line, and there are major restrictions on the means for adjusting fluctuations in peak values. . In particular, it is not always possible to reduce fluctuations in the peak value due to the effects of temporal fluctuations in the inductance of the load 5 and the stray capacitance of the saturable reactor used as a heater current blocking coil or magnetic switch connected to the load 5. It wasn't easy.

The present invention has been proposed to solve the problems of the prior art as described above. That is, an object of the present invention is to provide a pulse generator capable of supplying a rectangular wave pulse having a high voltage, a steep rise characteristic, a short pulse width, and a small fluctuation in the peak value.

[Configuration of the invention]

[0013]

[Means for Solving the Problems] As a means for achieving the above object, the present invention includes a Blumlein line connected to a charging power source and a switching element, and a load connected to the Blumlein line. On the other hand, a pulse generator for generating rectangular wave pulses is characterized in that a charging power source and an input terminal of a Blumlein line are connected via a variable inductance.

[0014]

[Operation] In the pulse generator of the present invention having the above configuration, by changing the magnitude of the variable inductance, the output waveform can be adjusted and fluctuations in the peak value can be suppressed.

[0015]

[Embodiment] Hereinafter, one embodiment of the present invention will be explained in detail with reference to FIG. Note that the same members as those in the prior art shown in FIGS. 2 and 3 are denoted by the same reference numerals, and explanations thereof will be omitted.

In this embodiment, as shown in FIG.
A cylindrical first conductor 71 and a second conductor 72 are arranged inside a third conductor 73 to form a coaxial Blumlein line 7. A saturable reactor 8 with a stray capacitance 9 is used as a switching element.

Further, the charging power source 1 is composed of a capacitor and a pulse transformer. A variable inductance 10 is provided between the charging power source 1 and the switching element 8.

In the pulse generator of this embodiment having such a configuration, the second conductor 72 charged through the variable inductance 10 by the charging power source 1 is grounded by the saturable reactor 8. Then, a step wave having a rising characteristic determined by the switching characteristic of the saturable reactor 8 is input to the distributed constant line constituted by the third conductor 73 and the second conductor 72.

At this time, resonance occurs due to the stray capacitance 9 and residual inductance of the saturable reactor 8. The vibrations caused by this resonance are superimposed on the output waveform of the Blumlein line and distort the output waveform. In order to prevent vibrations caused by this resonance from causing fluctuations in the output waveform of the Blumlein, it is necessary to cancel this vibration.

In this embodiment, by changing the value of the variable inductance 10 installed between the charging power source 1 and the Blumlein line, the resonant frequency of the circuit consisting of the inductance of the charging power source 1 and the variable inductance 10 is changed. can be done. Therefore, by appropriately adjusting this resonant frequency, vibrations caused by resonance with the residual inductance and stray capacitance of the saturable reactor 8 can be canceled out. As a result, it is possible to suppress vibrations in the peak value of the output waveform.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and for example, the switching element may be constructed of a switch other than a saturable reactor, such as a thyratron.

[0022]

[Effects of the Invention] As described above, according to the present invention, by simply connecting the charging power source and the input side terminal of the Blumlein line through a variable inductance, a steep rise characteristic can be achieved at high voltage. Therefore, it is possible to provide a pulse generator that can supply a rectangular wave pulse with a short pulse width and little variation in peak value.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of a pulse generator of the present invention.

FIG. 2 is a circuit diagram of a conventional pulse generator using a pulse transformer.

FIG. 3 is a circuit diagram of a conventional pulse generator using Blumlein.

[Explanation of symbols]

1...Charging power source 7...Coaxial Blumlein line 71...First conductor 72...Second conductor 73...Third conductor 8...Saturable reactor 9... Stray capacitance 10...Variable inductance

Claims (1)

[Claims] 1. A pulse generator comprising a Blumlein line connected to a charging power source and a switching element, the pulse generator generating a rectangular wave pulse to a load connected to the Blumlein line, comprising: a charging power source and a Blumlein line connected to the Blumlein line; A pulse generator characterized in that the input side terminal of the pulse generator is connected via a variable inductance.