Investigation of Pre-Ionization Characteristics in Heavy Gas Pulsed Inductive Plasmas Via Numerical Modeling
A globally-averaged, pulsed inductive plasma model is reproduced and utilized to investigate pre-ionization conditions for a pulsed inductive plasma accelerator. Attention is given to better quantifying the formation and energy conversion/loss processes associated with the pre-ionization stage. Simulations are completed for different power input pulse duration, seed plasma density, and total input energy. Results are analyzed based on the ion energy fraction and peak ion density. Ion energy fraction is the percentage of total input energy contained in ionization. Analysis shows that reducing pulse duration from 10ˉ⁶ to 10ˉ⁷ seconds increases ion energy fraction by 16.5%. Reducing pulse duration further to 10ˉ⁸ seconds increases ion energy fraction only another 2.5%. The optimum pulse duration from these simulations is 200 ns because this duration maximizes both ion energy fraction and peak ion density. Results show that a low seed plasma density, less than 10¹⁴ mˉ³, yields the highest ion energy fraction of 40%. Increasing seed plasma density above 10¹⁴ mˉ³ increases peak ion density but causes a corresponding decrease in ion energy fraction. Increasing total energy deposition from 5 to 160 mJ increases ion energy fraction from 33 to 58% at a 200 ns pulse duration. However this increase is not linear, but has a diminishing return with ion energy fraction plateau estimated to be 65%.
W. C. Meeks et al., "Investigation of Pre-Ionization Characteristics in Heavy Gas Pulsed Inductive Plasmas Via Numerical Modeling," Joint Propulsion Conferences, American Institute of Aeronautics and Astronautics (AIAA), Jan 2011.
The definitive version is available at http://dx.doi.org/10.2514/6.2011-5655
47th AIAA/ASME/SAE/ASEE Joint Propulsion Conferences & Exhibit
Mechanical and Aerospace Engineering
Article - Conference proceedings
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