Thyratron
#thyratron
#gas tube
#hot-cathode
#grid control
#electron tube
#non-self-sustaining arc
#gas-filled tube
#control electrodes
Description: A hot-cathode gas tube featuring one or more control electrodes that initiate but do not limit the anode current, except under specific operating conditions. This component is also referred to as a hot-cathode gas-filled tube. It is a gas-filled electron tube, typically comprising three electrodes, with either a hot or cold cathode and grid control that regulates the initiation time of a non-self-sustaining arc. In the former scenario, it results in a discharge, while in the latter, a glow discharge occurs within the gas filling the tube. After initiation, the grid of a thyratron can no longer control the anode current. In contrast to a tacitron, the discharge in a thyratron can only be extinguished by reducing the anode voltage below the rated discharge voltage. Pulse-forming thyratrons are extensively used, particularly in circuits designed for shaping high-power pulses of electric current, serving as switching devices in radar transmitter modulators. When a pulsed voltage of 100 to 300 volts is applied to the grid of a pulse-forming thyratron, an auxiliary discharge is initiated in the space between the grid and the cathode. As the grid current and the concentration of charged particles near the grid (within the anode field) reach critical levels, an arc-discharge plasma forms rapidly between the anode and cathode. This process, which occurs in just a few tens of nanoseconds, results in a swift increase in anode current and a decrease in voltage, transitioning the thyratron from a fired to an unfired state. During the operation of pulse-forming thyratrons, discharge is typically initiated periodically at the grid pulse repetition rate. Each initiation causes the pulse-forming line to discharge through a load, such as a magnetron. During discharge, the voltage across the thyratron decreases from approximately 2Ea to below the arcing potential, extinguishing the discharge. Consequently, current pulses flow through the load at regular intervals. Existing types of pulse-forming thyratrons can produce current pulses ranging from 1 to 5,000 amperes and pulse lengths from 0.1 to over 6 microseconds, with repetition rates reaching up to 30 kilohertz for short pulse lengths. These thyratrons, with efficiencies ranging from 95 to 98 percent, are characterized by high stability in initiation time (with pulse leading edges varying by no more than 3 nanoseconds), short recovery times, and high reliability. The anode voltage of high-power thyratrons can reach as high as 100 kilovolts. Most pulse-forming thyratrons are filled with hydrogen at pressures between 25 and 95 newtons per square meter, while deuterium and hydrogen-deuterium mixtures are less commonly used. For low currents (10 to 50 milliamperes) and low anode voltages (150 to 300 volts), glow-discharge thyratrons with one or more grids and current control, similar to pulse-forming thyratrons, or electrostatic control are also utilized. Electrostatic control necessitates an additional electrode known as the priming grid. The significant recovery time (thousands of microseconds) and slow response of glow-discharge thyratrons limit their applications primarily to low-frequency devices in computer technology, automatic control, and physical experiments. An example of such thyratrons is their use in sawtooth voltage generators. A promising variant of glow-discharge thyratrons is the indicator type.
Pulse-forming thyratrons play a crucial role in high-power pulse generation applications. They are employed in various systems requiring rapid switching capabilities, such as radar systems, laser pulsing, and high-voltage power supplies. The operational principle relies on the precise control of the discharge initiation through the grid, allowing for the rapid formation of an arc discharge that can handle substantial current levels. The design typically includes a robust structure to withstand the high-voltage operation and ensure reliability under repetitive firing conditions.
The schematic representation of a linear modulator incorporating a pulse-forming thyratron would include components such as a charging choke (Lch), a pulse-forming line (PL), a supply voltage (Ea), a coupling capacitor (Cc), the thyratron itself (PT), a control-circuit resistor (Rc), and an equivalent load resistance (Z). The grid voltage pulses (er) are crucial for controlling the discharge timing, ensuring that the system can produce the desired output waveform accurately.
In applications where low-current and low-voltage operations are necessary, glow-discharge thyratrons serve as a viable alternative. Their design may involve multiple grids to enhance control over the discharge process. However, the inherent limitations in recovery time and response speed necessitate careful consideration of their application scope, often relegating them to specific uses within automated systems and experimental setups.A hot-cathode gas tube in which one or more control electrodes initiate but do not limit the anode current except under certain operating conditions. Also known as hot-cathode gas-filled tube. a gas-filled electron tube, usually having three electrodes, with a hot or cold cathode and grid control of the initiation time of a non-self-sustaining arc
discharge in the former case or a glow discharge in the gas filling the tube in the latter case. After initiation, the grid of a thyratron can no longer control the anode current. In contrast to a tacitron, therefore, the discharge in a thyratron can be extinguished only by reducing the anode voltage to a value less than the rated discharge voltage. ) have been replaced almost entirely by semiconductor devices, mainly thyristors. Pulse-forming thyratrons, however, are widely used ”mainly in circuits for shaping high-power pulses of electric current (primarily as switching devices in the modulators of radar transmitters).
When a pulsed voltage with an amplitude of 100 300 volts is supplied to the grid of a pulse-forming thyratron, an auxiliary discharge is initiated in the space between the grid and the cathode. When the grid current and, correspondingly, the concentration of charged particles near the grid (in the region penetrated by the anode field) rise to critical values, the rapid process of formation of an arc-discharge plasma between the anode and cathode commences.
In this process, which takes only a few tens of nanoseconds, the anode current increases rapidly, the voltage decreases, and the thyratron switches from the fired to the unfired state. During the operation of pulse-forming thyratrons (for example, in a linear modulator; see Figure 1), the discharge is usually initiated periodically at the repetition rate of the grid pulses.
Each time the thyratron discharge is initiated, the pulse-forming line discharges through the load, for example, a magnetron. In the process of discharge, the voltage across the thyratron decreases from ‰ 2 Ea to a value less than the arcing potential, and the discharge is extinguished.
As a result, periodically repeated current pulses flow through the load. Existing types of pulse-forming thyratrons make it possible to obtain current pulses ranging in amplitude from 1 to 5, 000 amperes and in length from 0. 1 to 6 microseconds or more at a repetition rate of up to 30 kilohertz (for short pulse lengths). The thyratrons, whose efficiency can be as high as 95 98 percent, are distinguished by high stability of the initiation time (the spread in the length of the leading edges of the pulses does not exceed 3 G— 10 9 sec), a short recovery time, and high reliability.
The anode voltage of high-power thyratrons may be as high as 100 kilovolts. Most pulse-forming thyratrons are filled with hydrogen at a pressure of 25 95 newtons per square meter; deuterium and mixtures of hydrogen and deuterium are used less often. At low currents (10 50 milliamperes) and with low anode voltages (150 300 volts), glow-discharge thyratrons with one or more grids and with current control, as in pulse-forming thyratrons, or electrostatic control are also used.
Electrostatic control requires an additional electrode, known as the priming grid. The considerable recovery time (thousands of microseconds) and slow response of glow-discharge thyratrons limit their range of application Figure 1. Schematic diagram of a linear modulator incorporating a pulse-forming thyratron: (Lch) charging choke, (PL) pulse-forming line, (Ea) supply voltage, (Cc) coupling capacitor, (PT) thyratron, (er) voltage pulses supplied to the grid, (Rc) control-circuit resistor, (Z) equivalent load resistance mainly to low-frequency devices used in computer technology, automatic control, and physical experiments.
For example, such thyratrons are used as sawtooth voltage generators. A promising variety of glow-discharge thyratrons is the indicat
Pulse-forming thyratrons play a crucial role in high-power pulse generation applications. They are employed in various systems requiring rapid switching capabilities, such as radar systems, laser pulsing, and high-voltage power supplies. The operational principle relies on the precise control of the discharge initiation through the grid, allowing for the rapid formation of an arc discharge that can handle substantial current levels. The design typically includes a robust structure to withstand the high-voltage operation and ensure reliability under repetitive firing conditions.
The schematic representation of a linear modulator incorporating a pulse-forming thyratron would include components such as a charging choke (Lch), a pulse-forming line (PL), a supply voltage (Ea), a coupling capacitor (Cc), the thyratron itself (PT), a control-circuit resistor (Rc), and an equivalent load resistance (Z). The grid voltage pulses (er) are crucial for controlling the discharge timing, ensuring that the system can produce the desired output waveform accurately.
In applications where low-current and low-voltage operations are necessary, glow-discharge thyratrons serve as a viable alternative. Their design may involve multiple grids to enhance control over the discharge process. However, the inherent limitations in recovery time and response speed necessitate careful consideration of their application scope, often relegating them to specific uses within automated systems and experimental setups.A hot-cathode gas tube in which one or more control electrodes initiate but do not limit the anode current except under certain operating conditions. Also known as hot-cathode gas-filled tube. a gas-filled electron tube, usually having three electrodes, with a hot or cold cathode and grid control of the initiation time of a non-self-sustaining arc
discharge in the former case or a glow discharge in the gas filling the tube in the latter case. After initiation, the grid of a thyratron can no longer control the anode current. In contrast to a tacitron, therefore, the discharge in a thyratron can be extinguished only by reducing the anode voltage to a value less than the rated discharge voltage. ) have been replaced almost entirely by semiconductor devices, mainly thyristors. Pulse-forming thyratrons, however, are widely used ”mainly in circuits for shaping high-power pulses of electric current (primarily as switching devices in the modulators of radar transmitters).
When a pulsed voltage with an amplitude of 100 300 volts is supplied to the grid of a pulse-forming thyratron, an auxiliary discharge is initiated in the space between the grid and the cathode. When the grid current and, correspondingly, the concentration of charged particles near the grid (in the region penetrated by the anode field) rise to critical values, the rapid process of formation of an arc-discharge plasma between the anode and cathode commences.
In this process, which takes only a few tens of nanoseconds, the anode current increases rapidly, the voltage decreases, and the thyratron switches from the fired to the unfired state. During the operation of pulse-forming thyratrons (for example, in a linear modulator; see Figure 1), the discharge is usually initiated periodically at the repetition rate of the grid pulses.
Each time the thyratron discharge is initiated, the pulse-forming line discharges through the load, for example, a magnetron. In the process of discharge, the voltage across the thyratron decreases from ‰ 2 Ea to a value less than the arcing potential, and the discharge is extinguished.
As a result, periodically repeated current pulses flow through the load. Existing types of pulse-forming thyratrons make it possible to obtain current pulses ranging in amplitude from 1 to 5, 000 amperes and in length from 0. 1 to 6 microseconds or more at a repetition rate of up to 30 kilohertz (for short pulse lengths). The thyratrons, whose efficiency can be as high as 95 98 percent, are distinguished by high stability of the initiation time (the spread in the length of the leading edges of the pulses does not exceed 3 G— 10 9 sec), a short recovery time, and high reliability.
The anode voltage of high-power thyratrons may be as high as 100 kilovolts. Most pulse-forming thyratrons are filled with hydrogen at a pressure of 25 95 newtons per square meter; deuterium and mixtures of hydrogen and deuterium are used less often. At low currents (10 50 milliamperes) and with low anode voltages (150 300 volts), glow-discharge thyratrons with one or more grids and with current control, as in pulse-forming thyratrons, or electrostatic control are also used.
Electrostatic control requires an additional electrode, known as the priming grid. The considerable recovery time (thousands of microseconds) and slow response of glow-discharge thyratrons limit their range of application Figure 1. Schematic diagram of a linear modulator incorporating a pulse-forming thyratron: (Lch) charging choke, (PL) pulse-forming line, (Ea) supply voltage, (Cc) coupling capacitor, (PT) thyratron, (er) voltage pulses supplied to the grid, (Rc) control-circuit resistor, (Z) equivalent load resistance mainly to low-frequency devices used in computer technology, automatic control, and physical experiments.
For example, such thyratrons are used as sawtooth voltage generators. A promising variety of glow-discharge thyratrons is the indicat
A simple grid control circuit
A, B, and C are used for a large power split-phase system. The A + BC range generator phase line features an A-A indole path string containing two 220V/15W bulbs. The bulbs recover based on macro instructions from J Sweet...