Conveners
2.6 Non-Fusion Microwave Systems and 2.7 Microwave Plasma Interaction I
- Sarita Prasad (UNM)
- John Leopold (Technion)
Description
This is a combined session
A tunable electrically small antenna (ESA) designed for transportable ionospheric heating (TIH) is presented as a practical implementation of a previously presented, basic design. Traditionally, Ionospheric Heating is achieved using large multi-element arrays of dipoles or similar antennas. One such array, the HAARP IRI, occupies 0.14 km2 in Gakona, Alaska with 180 crossed dipole elements. The...
The behavior of the breakdown in air at RF frequencies for different gap lengths has been studied numerically at atmospheric pressure. The focus here is on gap lengths in the 1–5 mm range. A numerical analysis based on Monte Carlo calculations as discussed previously [1] is applied, with explicit inclusion of photon processes. The simulation results are compared with experimental data...
A high average power, pulsed RF source operating at 2.85 GHz is described for use in multipactor research. Four state of the art GaN HEMTs from Cree/Wolfspeed capable of 700 W in long pulse mode (~ 100 μs) each are combined for a total maximum power output of 2.8 kW with a rated output of 2 kW total. A low phase noise, free running 55 MHz modulation capable VCO is used as the RF source,...
Multipactor is known to jeopardize the performance of vacuum electronic devices and high-power microwave systems. Though most treatments have focused on the secondary emission from incident primary electrons, the overall process is quite complicated. It involves not just the role of primary electrons, but also the effects of incident ions that might produce secondary electrons and/or cause...
Multipactor is cascade avalanche growth of free electrons in RF components under vacuum. In two-surface multipactor, a free electron gets accelerated by electric field and impacts a facing surface with enough energy to liberate secondary electrons. Cascade evolution of these electrons under certain conditions can load and short circuit the RF power.
We will discuss the design and...
Multipactor is a vacuum discharge based on secondary electron emission that plagues microwaves devices, accelerator structures, and space-borne systems [1]. A novel theory based on principles from nonlinear dynamics and chaos theory has been introduced, in which all possible modes are recovered with no a priori assumptions on the electron trajectories [2-3]. The new methodology systematically...
