JP2837100B2 - Pulse power supply for klystron - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse power supply device for a klyston which supplies a high-voltage pulse power supply to an electron accelerator used in a free electron laser device or the like.

[0002]

2. Description of the Related Art A free electron laser device (hereinafter referred to as FEL) guides an electron beam accelerated to a speed close to the speed of light by an electron accelerator into a wiggler magnetic field, and generates a laser beam by induced radiation by a resonance action with the magnetic field. I do. In the electron accelerator,
In order to accelerate the electron beam generated from the hot cathode of the electron gun to a relativistic speed close to the speed of light in a very short time, a high frequency is output by a klystron and a high frequency electric field is formed by an acceleration tube.

The klystron pulse power supply is
A pulse shaping circuit (hereinafter abbreviated as PFN) composed of a charger and a variable inductance reactor connected in series, and a capacitor connected in parallel corresponding to each reactor;
It has a main switch provided in the PFN for discharging the charge stored in the PFN, a pulse transformer for supplying a pulse high voltage to the klystron, and a voltage divider for measuring the output voltage.

[0004]

In the above-mentioned conventional klystron pulse power supply device, a voltage divider is inserted to measure whether or not the secondary voltage of the pulse transformer applied to the klystron is within a predetermined range. ing.
The output waveform from the voltage divider is connected to a monitor and measured. If the output voltage fluctuates from a predetermined range as a result of the measurement, the output voltage is adjusted by finely adjusting the inductance value of the variable reactor. In adjusting the output waveform from the voltage divider, the output voltage decreases as the inductance value of the variable reactor of the PFN increases, and conversely, the output voltage increases if the inductance value of the variable reactor decreases.

However, in this adjustment method, the adjustment of the variable reactor is manually performed from the output waveform observed on the monitor, and the output waveform is observed again after the adjustment. There is a problem of wasting labor.

When the manual adjustment is used for an electron beam accelerator or the like, not only the initial startup adjustment of the accelerator or the like but also the manual adjustment in which the state gradually changes over time during normal operation due to long-term use. May need to be done.

The present invention has been made in view of such a problem of the conventional high-frequency pulse power supply device, and monitors the output voltage of the pulse transformer so that the fluctuation range of the output voltage is within a predetermined range. It is an object of the present invention to provide a pulse power supply device capable of automatically adjusting the inductance of a variable reactor of a pulse shaping circuit and suppressing a fluctuation of an output voltage within a predetermined range with high accuracy at the time of start-up and normal operation of an accelerator.

[0008]

As a means for solving the above-mentioned problems, the present invention provides a pulse forming circuit comprising a charger for supplying electric charge to a connected circuit, a capacitor and a reactor having a variable inductance, and a circuit for forming the pulse. Main switch for releasing stored charge, pulse transformer for supplying pulsed high voltage to klystron, and part 2
Comprising a voltage divider for measuring the following side output voltage, the fixed length co for the variable reactor is that the inductance is variable
Drive unit on a movable plunger movably provided inside the il
And a control unit for adjusting a variable reactor via a driving unit so as to analyze a waveform of the output voltage measured by the voltage divider and adjust a variation width thereof within a predetermined range. It was.

[0009]

In the pulse power supply device of the present invention having the above-described configuration, the electric charge stored in the pulse shaping circuit is supplied to the main switch to generate a high-frequency pulse high voltage on the secondary side of the pulse transformer.

The high pulse voltage is measured by a voltage divider, and its output signal is sent to a control unit, where the high pulse voltage value and its waveform are detected. Then, it is determined whether the fluctuation range of the high voltage value is within a predetermined range. If the fluctuation range is outside the predetermined range, a variable reactor corresponding to the moment is specified, and a driving unit of the variable reactor is controlled to be movable inside the coil. Plunge
By adjusting the output voltage, the inductance is adjusted, and the output voltage is automatically adjusted to be within a predetermined range.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a klystron pulse power supply circuit according to an embodiment. 1 charger supplies charges to the circuit connected thereto, 2 and a plurality of reactor L _1, L ₂ ...... L _n inductance variable connected in series,
Correspondingly, capacitors C ₁ , C ₂ .
... consist C _n, a pulse shaping circuit for generating a rectangular pulse voltage with an electric charge is charged.

3 is a main switch using a thyratron, 4
Is a pulse transformer for supplying a pulse high voltage, 5 is a voltage divider for measuring a secondary side output voltage of the pulse transformer, and 6 is a klystron. The main switch 3 may be an optical thyristor instead of the thyratron. The klystron 6 forms a high-frequency pulsed electric field at a high voltage. In this embodiment, the klystron 6 is used for an RF accelerator for accelerating an electron beam, such as a free electron laser device.

In the present embodiment, the pulse power supply circuit having the above-described configuration is provided with an automatic waveform adjusting device 10 having a voltage divider 5 for measuring the output voltage of the pulse transformer 4 as an input signal. The adjusting device 10 is provided with the variable reactors L ₁ , L
It is provided as a control unit for automatically adjusting the ₂ ...... L _n.

The variable reactors L ₁ , L ₂ ... L _n are provided with a movable plunger or cylinder 13 inside a coil 12 wound around a bobbin 11 as shown in FIG. M ₂ ... M _{n so as} to be movable. The motors M ₁ , M ₂ ... _Mn are configured such that the output shaft can move in the axial direction by rotation. The motors M ₁ , M ₂ ... _Mn may be of a solenoid type.

The above-mentioned automatic waveform adjusting apparatus 10 is actually a computer and is not shown in the drawings. However, the motors M ₁ , M ₂ ... _Mn include driving units D ₁ , D _{2. n}
There are connected, one of these driving unit D _1, D ₂ ...... D _n and controlled by the control signals from the computer to adjust the inductance of the variable reactor L _1, L ₂ ...... L _n with.

The computer has an I / O boat, a central processing unit (CPU), a temporary storage unit (RAM), and a fixed storage unit (ROM), and these are connected by a bus circuit.
When an input signal from the voltage divider is read, a determination unit for determining whether the input signal is within a predetermined range as the output voltage of the pulse transformer by arithmetic processing is provided in the ROM,
A control signal is sent to the drive unit based on the result of the determination.

The operation of the pulse power supply device of the embodiment having the above configuration will be described. The pulse power supply device of this embodiment supplies a pulse power supply for a klystron used in an RF accelerator such as a free electron laser. FIG.
As shown in, the charge from the charger 1 is stored in each capacitor C _1, C ₂ ...... C _n of PFN the main switch 3 in the OFF state. When the main switch 3 is turned on, the capacitor C
₁ , C ₂ ... The electric charges stored in C _n flow into the pulse transformer 4 instantaneously, with a slight delay, and generate a high voltage on the secondary side thereof.

After the generation of the high voltage, the capacitors C ₁ , C _2, ..., C _n are charged again and when they reach a predetermined level, the main switch 3 is turned on and the high voltage is supplied to the pulse transformer 4. The main switch 3 is turned on and off according to the repetition of the energization and charging, whereby a pulse high voltage is supplied to the klystron 6.

FIG. 3 shows (b) corresponding to the PFN of (a).
Shows a voltage waveform for one pulse. This voltage waveform is a combined voltage obtained by combining the voltages generated at the capacitors C ₁ , C _2, ..., C _n . In a klystron, the variation of the combined voltage ΔV is used to generate a high quality electron beam.
Requires high accuracy within a few percent of the predetermined voltage.

However, the variable reactors L ₁ , L ₂ ... L
_{In n} , the fluctuation of the combined voltage may deviate from the range of ΔV as shown by the dotted line in FIG.

Therefore, in this embodiment, the automatic waveform adjustment device 10 automatically adjusts the voltage to supply a composite voltage as flat as possible. As described above, the automatic waveform adjusting device 10 using the computer reads the output voltage of the pulse transformer based on the input signal from the voltage divider 5, analyzes the waveform, and the fluctuation range of the output voltage is within the predetermined range ΔV. Is determined by the determination unit.

Therefore, a target flatness ΔV is set,
For example, when the waveform is as shown by the dotted line in FIG.
Indexing time falls below the V, when the variable reactor corresponding thereto and L _n-1 control signal to the output waveform by reducing the inductance of the L _n-1 stages is adjusted to fall within the ΔV Is applied to the motor M _n-1 to perform instantaneous adjustment. Thus, the fluctuation of the output voltage of the pulse transformer 4 is automatically adjusted within a predetermined range.

[0023]

As described above in detail, the pulse power supply device of the present invention supplies the electric capacity stored in the pulse shaping circuit to the pulse transformer by energizing the main switch to generate a high-frequency pulse high voltage on the secondary side thereof. The pulse high voltage is measured by a voltage divider, and the control section moves the variable plunger of the pulse shaping circuit within the coil so that the fluctuation of the pulse high voltage is within a predetermined range based on the measurement signal.
It is so arranged to adjust the a, it can be automatically adjusted to be within a predetermined range with extremely high precision pulse high voltage at the time when and normal operation rising of the accelerator, obtain the advantage of being very useful in improving the work efficiency Can be

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a pulse power supply circuit according to an embodiment.

FIG. 2 is a configuration diagram of a variable reactor.

FIG. 3 is an explanatory diagram of an operation.

[Explanation of symbols]

1 charger 2 pulse shaping circuit 3 main switching 4 pulse transformer 5 divider 6 klystron 10 automatic waveform adjustment device C ₁ ~ _n capacitors L ₁ ~ _n variable reactor M ₁ ~ _n motor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H03K 3/55 H01S 3/30 H03K 3/57 H05H 7/02

Claims (1)

(57) [Claims] 1. A charger for supplying electric charge to a circuit to be connected, a pulse shaping circuit comprising a capacitor and a reactor having a variable inductance, a main switch for discharging the electric charge stored in the shaping circuit, and a pulse high voltage applied to a klystron. And a voltage divider for measuring a secondary output voltage of the variable reactor, wherein the variable reactor has a fixed-length coil for varying inductance.
Connect the drive unit to a movable plunger movably provided inside the
A pulse power supply device for a klystron, comprising: a control unit that analyzes a waveform of an output voltage measured by a voltage divider and adjusts a variable reactor via a driving unit such that a variation width thereof is within a predetermined range.