Ding Wenjing, Feng Jinjun, Zhang Ming, Yang Hongfei
Vacuum Electronics Research Institute, Beijing 100015, China
Email: fengjinjun@tsinghua.org.cn
Abstract text. The pseudospark switch works in the left branch of
Paschen curve with low gas pressure, which has the advantage of short
electrode breakdown time (<10ns), large pulse current
(>100kA), and long lifetime, etc. High pulse repetition
frequency (PRF) pseudospark switch has important applications in food
processing, sewage treatment, high energy laser system, sonar syste, and
other fields, the pseudospark switch with a PRF of kHz-level is needed.
This paper focuses on the pseudospark switch with double-pulse trigger
structure, and the corresponding relationship between the two trigger
voltages and current is calculated respectively, and the influence of
the two pulses on the trigger process is analyzed. Then the pseudospark
switch with this structure is tested with the anode voltage of 10kV for
different voltage and gas pressure. The results show that the minimum
trigger voltage is only 100V, and the switch can work stably with high
repetition frequency.
Introduction: In engineering practice and scientific research,
the increasing development of pulse power technology also requires the
subsequent progress of switching devices, especially in the field of
high PRF has urgent application needs and huge space for development,
such as in the military field, for underwater communication and
underwater confrontation, the need for 10 kHz to 100 kHz with sonic high
repetition frequency switches. High power and high repetition frequency
switches of GW class kHz are also required in high energy laser
weapons[1]. In daily life and industrial production, high pulse
repetition frequency switches can greatly improve work efficiency in
sewage treatment, food processing and other fields[2-3]. The
existing pulse power technology switches include solid switches,
thyratron switches, field distortion switches, pseudospark switches and
so on. However, only the pseudospark switch can combine high power and
high PRF performance. In the Z-pinch nuclear fusion device, the
pseudospark switch is the only switch with PRF operation
capability[4]. Therefore, the pseudospark switch with high
repetition frequency is one of the leading directions of the development
of high power pulse field in the world.
Double-pulse triggering structure: V.D. Bochkov et al. [5-6]
of the Russian Institute of High Current Electronics developed a series
of commercial high repetition frequency pseudospark switches (TPI type).
All of them adopt the structure of glow discharge and double-pulse
triggering, and the PRF reaches 20kHz.
Based on the electrode structure of glow discharge and double-pulse
trigger [7], we designed the high PRF pseudospark as shown in Figure
1(a), which is composed of hollow anode, grid, hollow cathode and glow
trigger structure, and the trigger structure includes auxiliary glow
discharge anode, auxiliary emission electrode and Faraday cup, its photo
shown in Figure 1(b). Dual pulse triggering is divided into main-trigger
voltage Utcp1 and pre-trigger voltage
Utcp2. The Utcp2 is applied to the
auxiliary glow discharge anode, and the Utcp1 is to the
grid. The electronic path is shown in the arrow in Figure 1(a). In order
to verify the effectiveness of double-pulse triggering and the influence
of pre-trigger and main trigger pulses on the discharge process, this
paper tests the pulse repetition frequency performance of the structure
under different gas pressure and trigger voltage, and simulates the
trigger unit to observe the influence of different trigger voltages on
the cathode current.