Performance of magnetically-injected-plasma opening switches on the particle beam fusion accelerator II (PBFA II)

Summary form only given, as follows. Plasma opening switch (POS) experiments have been performed on the PBFA II to develop a switch which will provide voltage and power gain to an applied-B lithium ion diode. These experiments have successfully coupled power to electron and ion beam diodes using a magnetically-injected-plasma (MIP) POS. Carbon plasma with electron densities of 1×10¹² to 2×10 ¹³/cm³ has been injected from the anode into the 8-cm gap of the 20-Ω magnetically insulated transmission line (MITL) of PBFA II along a B_r.z magnetic field. The MIP switch uses the inertia of the plasma to keep the switch closed and the magnetic pressure of B₀ from the conduction current to open the switch. The configuration of the injecting magnetic field and the plasma source, has a significant effect on the efficiency of coupling power to high-impedance loads. Plasma near the center of the injecting magnetic field limits the opening impedance of the switch and subsequently the power delivered to the load. The axial location of the switch with respect to the load has also been identified as a critical parameter in increasing the coupling efficiency. A length of 10 to 20 cm of MITL between the POS and the load has increased the power delivered to the load