Design and investigation of a capacitance-coupling pre-ionized sharpening switch

Area of Science:

• Electrical Engineering
• Pulsed Power Systems
• High Voltage Technology

Background:

• The sharpening switch is crucial for trigger generators, impacting output stability.
• Its breakdown performance directly influences the trigger pulse's front sharpening.
• Existing designs require optimization for improved jitter and pulse sharpening.

Purpose of the Study:

• To propose and investigate a novel 200 kV capacitance-coupling pre-ionized sharpening switch.
• To optimize the pre-ionized sharpening switch parameters for best breakdown performance.
• To experimentally evaluate the influence of electrode structure, material, and gap distances.

Main Methods:

• Experimental investigation of electrode structure (circular knife-edged cathode, plate anode), material (stainless steel, graphite, aluminum, brass), and gap distances (main and pre-ionized).
• Analysis of breakdown performance, focusing on jitter and stability.
• Evaluation under a 200 kV input voltage pulse with a ~1 microsecond rise time.

Main Results:

• The circular knife-edged cathode and plate anode structure yielded the lowest breakdown jitter.
• Stainless steel electrodes demonstrated the smallest jitter compared to graphite, aluminum, and brass.
• Optimal performance was achieved with main and pre-ionized gap distances of 13 mm and 1.5 mm, respectively.
• The optimized switch exhibited a jitter of 6.08 ns (0.6% of input pulse rise time), a 44.5% reduction from non-pre-ionized switches.
• Output pulse rise time was sharpened to 17 ns, achieving a voltage rise rate exceeding 11 kV/ns.

Conclusions:

• The novel capacitance-coupling pre-ionized sharpening switch offers superior breakdown stability and reduced jitter.
• Optimized parameters, including electrode design and gap distances, are critical for performance enhancement.
• This technology significantly improves trigger pulse sharpening and overall trigger generator performance.