Pellet acceleration in an electrothermal plasma gun.

摘要

The electrothermal launcher SIRENS has been modified to be used as a pellet injector. The source produces high-density (;A break-wire system has been fabricated to serve as a diagnostic system for measuring the pellet velocity. Device parameters which were varied during the course of the experiment included the input energy, the pulse length of the discharge, the length of the pellet acceleration path, and the pellet mass. Several pellets were accelerated during the course of the study, ranging from 300 to 1000 milligrams. A sabot device was tested to help accelerate a smaller pellet payload.;The 1-D, time dependent gas dynamics code "ODIN" (Hurley, 1993) was modified to include a section to model the pellet's movement, and the additional pellet terms were included in the set of governing equations. The pellet movement as predicted by the code compared favorably with experimental results, and the plasma parameters within the electrothermal launcher behaved as predicted.;Pellet velocity exceeding 2 km/s has been achieved in the SIRENS device, making it a viable fueling system for future fusion reactors. Modeling of the device has been compared to results from short and medium current pulse length experimental shots. Following benchmarking, the code was used to predict the performance of the device for various theoretical input current pulses. Variables in this theoretical modeling included current pulse length, maximum current amplitude, and pulse shape. Predictions showed pellet exit velocities for an optimally arranged current profile approaching 4000 m/s.