Thyratron

Abstract: 1 General Switching Considerations.- 2 Electrical Breakdown In Gases In Electric Fields.- 3 Gas Filled Spark Gaps.- Section 3a Self Breakdown Gaps.- Section 3b Trigatron Spark Gaps.- Section 3c Field Distortion Three Electrode Gaps.- Section 3d Electron Beam Triggering of Gas Filled Spark Gaps.- Section 3e Laser Triggering of Gas Filled Spark Gaps.- 4 Vacuum Switches.- Section 4a Electrical Breakdown in Vacuum.- Section 4b Recovery of Vacuum Spark Gaps.- Section 4c Triggered Vacuum Switch Construction and Performance.- 5 Repetitive Operation and Lifetime Considerations for Spark Gaps.- Section 5a Repetitive Spark Gap Switches.- Section 5b Lifetime Considerations.- 6 Surface Discharge Switches.- 7 Thyratrons.- Section 7a Design Principles and Operation Characteristics.- Section 7b Hydrogen Thyratrons and Their Applications as Developed in the UK.- Section 7c Studies of Fundamental Processes in Thyratrons.- Section 7d Fundamental Limitations of Hydrogen Thyratron Discharges.- 8 Metal Vapor Switches.- Section 8a The Mercury-Pool-Cathode Ignitron.- Section 8b Liquid-Metal Plasma Valves.- 9 The Pseudospark Switch.- Section 9a The Pseudospark.- Section 9b The Triggered Pseudospark Discharge.- Section 9c The Back-Lighted Thyratron.- Section 9d High Power, High Current Pseudospark Switches.- Section 9e Pseudospark Switches for High Repetition Rates and Fast Current Risetimes.- Contributors.

Abstract: A review is presented of recent developments in a new group of high-power hollow-electrode switches, including the pseudospark and the backlighted thyratron (BLT). Experiments demonstrate that for several key high-power switching performance factors, the pseudospark and BLT switches are superior to either high-pressure spark gap switches or thyratrons or, in some cases, both. High performance has been demonstrated in peak current (>100 kA), current rate of rise (>10/sup 12/ A/s), switching precision, trigger efficiency, current reversal (100%), and recovery time. Several electrical and optical trigger methods have been demonstrated and are described. >

Abstract: The vacuum ultraviolet continua of the rare gases helium (580–1100 A), argon (1050–1550 A), krypton (1250–1800 A), and xenon (1480–2000 A) have been excited in a condensed discharge using a recently developed thyratron modulator excitation unit which gives sufficient intensity for photoelectric scanning at a bandwidth of 0.25 A. The optimum conditions for excitation have been studied. The continua excited in this manner have been compared with microwave-excited continua and found to be significantly more intense for argon and about the same intensity for krypton and xenon. It was not possible to obtain the helium continuum using microwave excitation. Time-resolved measurements of the light emission, current, and voltage made for these continua show that the light emission may begin either before or after the current pulse.

Abstract: A pseudo-spark switch triggered by a pulsed low-current gas discharge has been developed. It switches medium voltages and currents of typically less than 20 kV and 10 kA, respectively. The switch works at high repetition rates of up to 100 kHz and fast rates of current rise of up to 5*1011 A s-1. At positive charging voltage, the jitter may be much smaller than 1 ns. This pseudo-spark switch has been successfully tested by running a discharge-heated longitudinal copper vapour laser and a transverse Blumlein N2 laser, replacing a hydrogen thyratron and a high-pressure spark gap switch, respectively.