SGER: Exploratory Investigation of Simulation of Solar Plasma with Accelerated Compact Toroid

University Of California-Davis, Davis CA

Investigators

Abstract

The investigators will generate magnetic plasmoids that can excite non-linear processes relevant to solar and inter planetary plasmas. The main effort is to develop the laboratory diagnostics capable of measuring the non-linear processes and to develop theoretical and computer models of the physical processes and their relevancy to solar and interplanetary plasmas. The Spheromak-like compact toroid (SCT) is a magnetized blob of ionized material (plasmoid) with self-generated equilibrium magnetic field structures that can confine the plasma over its lifetime of several tens of microseconds. This type of plasmoid is of great interest in laboratory magnetic fusion experiments and its development has been supported through DOE projects. One of the unique properties of the SCT is that it can withstand a tremendous accelerating force, so high speed (over 100 km/sec) can be reached in relatively short distance. Therefore, SCT accelerators are fairly compact and easily usable in laboratory experiments. In the past, one of the drawbacks of the SCT accelerator is the limit on its repetition rate by lack of high power repeatable switches. The low rate limits the use of this apparatus in physics experiment where statically meaningful database is required in a reasonable time frame. The investigators have now developed and operated a repeatable SCT accelerator using passive switching. At present, the pulse rate has increased from one per minute to one every 5 seconds. Improvement in the gas valve system will increase the rate to over 100 Hz. Moreover, the reliability of the accelerator has achieved over 1000 shots at the .2 Hz rate. Laboratory plasmas have the distinct advantage that its physical parameters can be carefully controlled and dynamic processes can be precisely diagnosed. Neither of these is possible with astrophysical plasmas.