A Plasma Electro-Optic Switch Driving Circuit Based on Pulsed Hydrogen Thyratron and Low Impedance Cable Blumlein Pulse Forming Line

Abstract

The invention discloses a plasma electro-optical switch driving circuit based on a pulsed hydrogen thyratron and a low-impedance cable Blumlein pulse-forming line. Whole low-impedance radio frequency high-voltage coaxial cable shaping rectangular high-voltage switch pulses are adopted, a pulse forming cable and a switch pulse transmission cable are integrated, and therefore a driving source system is reliable and simple in structure. The amplitude of output rectangular pulse voltage is equal to the pulse forming line charging high direct voltage amplitude, the charging voltage is low, the charging high direct voltage is closed by an insulating layer of the whole high voltage coaxial cable, and the insulating performance and reliability of the pulse forming line are high. The problems that a single artificial line or the cable shaping rectangular switch pulses require the charging voltage to be more than two times of the output pulse voltage, the charging voltage is high, the insulating requirement is high, and the number of output pulse transmission cables is large are solved.

Description

technical field [0001] The invention belongs to the research field of laser plasma electrode electro-optic switch drive technology, belongs to optoelectronics, and specifically relates to a plasma electrode electro-optic switch drive technology, which adopts low-impedance cable-type Blumlein pulse forming technology to obtain nanosecond-level rectangular high-voltage pulses for use in lasers. The driving pulse of the plasma electrode electro-optic switch, the flat-top amplitude of the output rectangular high-voltage switching pulse is equal to the charging voltage of the pulse forming line, which has the advantages of low charging voltage, small flat-top fluctuation of the output square wave high-voltage pulse, and the pulse forming cable doubles as a pulse transmission cable. System structure Features such as compactness. Background technique [0002] Plasma electrode electro-optic switch is the key technology to realize the principle of multi-pass chip power amplification ...

AI Technical Summary

Problems solved by technology

From the NIF high-power laser system of the Lawrence Livermore National Laboratory in the United States to the newly developed Shenguang 3 high-power laser system in China, the plasma electrode electro-optic switch pulses are formed using a single artificial wire or cable to shape the high-voltage rectangular switching pulse. The switching devices are all pulsed hydrogen thyratrons. The advantage of using a single artificial line is that the conduction inductance of the pulsed hydrogen thyratron has little influence on the pulse waveform. Disadvantages: A. The charging DC high voltage of the artificial line must be an output rectangle The pulse amplitude is more than twice, so the DC withstand voltage capability of the pulsed hydrogen thyratron must also be selected to be greater than twice the output pulse amplitude, which is not easy to improve the insulation and reliability of the system; B. Pulse forming unit and pulse The transmission unit is separated, the impedance of the pulse forming line, the transmission cable impedance and the parallel pure resistance load of the Pockels cell must be strictly consistent, otherwise it will affect the waveform of the output rectangular high-voltage pulse. In order to overcome the artificial line and the plasma electrode electro-optic switch terminal The impact of load mismatch on the rectangular pulse waveform, the length of the transmission cable must be greater than the output rectangular pulse width divided by the transmission rate of the pulse in the cable, for a rectangular high-voltage pulse with an output pulse width of 200ns, the transmission rate of the high-voltage pulse in the cable is 5 meters per nanosecond, the length of each set of plasma electrode electro-optic switch pulse transmission cable should be selected to be not less than 40m, for an array type high-power laser system, the number of plasma electrode electro-optic switches required is as many as tens to hundreds (64 sets for Shenguang 3, 192 sets for American NIF), the number of pulse transmission cables will be very large

At present, the large-scale array type high-power laser system requires the plasma electrode electro-optical switch drive pulse, and there are technical difficulties: the number of drive source pulse forming units is large, the insulation reliability is high, and the transmission cable is long and large in number

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