Radiation-enhanced dual-inverted bowlers antenna for high-power mesoband system.

We propose a novel radiation-enhanced dual-inverted bowlers antenna to pursue a maximal radiated electric field (E-field). Based on increasing the stored energy and the high-frequency component of the excitation pulse, the new structure significantly improves the radiation performance without increasing the generator output voltage or antenna size. Computer simulations show that the radiated E-field increases by a factor of 2.7 relative to the same sized conventional biconical antenna. Under a charge voltage of 300 kV, the experimental far-field voltage is 110 kV (22 kV/m at 5 m) and the voltage gain is 0.37. This voltage gain is an improvement of at least 23% over typical biconical antennas. This work brings new opportunities to improve the radiation performance of high-power mesoband systems.

Note: Design and investigation of a multichannel plasma-jet triggered gas switch.

We described the fabrication and testing of a multichannel plasma-jet triggered gas switch (MPJTGS). A novel six-channel annular micro-plasma-gun was embedded in the trigger electrode to generate multichannel plasma jets as a nanosecond trigger pulse arrived. The gas breakdown in multiple sites of the spark gap was induced and fixed around jet orifices by the plasma jets. We tested the multichannel discharge characteristics of the MPJTGS in two working modes with charge voltage of 50 kV, trigger voltage of +40 kV (25 ns rise time), and trigger energy of 240 J, 32 J, and 2 J, respectively, at different working coefficients. Results show that the average number of discharge channels increased as the trigger energy increased, and decreased as the working coefficient decreased. At a working coefficient of 87.1% and trigger energy of 240 J, the average number of discharge channels in Mode II could reach 4.1.

A novel low-jitter plasma-jet triggered gas switch operated at a low working coefficient.

In this paper, we described the fabrication and testing of a novel plasma-jet triggered gas switch (PJTGS) operated at extremely low working coefficients with excellent triggered jitters. While the structure of the PJTGS is similar to that of a traditional three-electrode field-distortion gas switch, to improve its triggered performance we used a conical micro-plasma-gun with a needle-to-plate spark gap embedded in the trigger electrode. Applying a nanosecond pulse to the trigger electrode caused a spark discharge in the micro-plasma-gun. The electric field drove the discharge plasma to spray into the spark gap of the gas switch, causing fast breakdown. We tested the PJTGS with charging voltages of ±25 kV and a trigger voltage of +80 kV (5 ns rise time and 80 ns full width at half maximum) in two working modes. The PJTGS operated in Mode II had a lower triggered jitter and could be operated over a wider range of working coefficients than in Mode I under the same conditions. At working coefficients higher than 70%, we obtained sub-ns triggered jitters (<0.89 ns) from the PJTGS, at working coefficients lower than 50%, we obtained triggered jitters of 1.6-3.5 ns without no-fires or pre-fires. Even at a working coefficient of 27.4%, the PJTGS could still be triggered reliably with a delay time of 96.1 ns and a triggered jitter of 3.5 ns, respectively.