Numerical Optimization of an Annular Field Reserved Configuration Translation Experiment

Abstract : Annular field reversed configuration (AFRC) devices form annular plasma toroids between a pair of concentric cylindrical coils. This plasmoid remains detached from the external magnetic _field so that it can be ejected from the coils, making AFRCs viable pulsed inductive plasma accelerators. Though numerous formation studies on AFRCs are available, no successful translation studies have been published. Michigan Technological University, in conjunction with the Air Force Research Laboratory, is investigating the translation of AFRCs as pulsed inductive plasma accelerators. The first step in this investigation is to develop an annular electromagnetic launcher model to study the basic translation characteristics of the device. The launcher model treats the plasmoid as a rigid conducting slug, accelerated out of the coils by a Lorentz force. It predicts coil and plasmoid currents, plasmoid trajectories, and acceleration efficiencies for various input conditions. The model has been optimized for peak acceleration efficiency using a combination of non-dimensional analysis, genetic algorithms, and gradient-based numerical optimization routines. A description of the model, explanation of the numerical optimization techniques, and preliminary results from the model are presented in this paper.

[1]  Jason Cassibry.  Comparison of Directly and Inductively Coupled Pulsed Electromagnetic Thrusters , 2008 .

[2]  R. Raman,et al.  Initial results from the Coaxial Slow Source FRC device , 1987 .

[3]  T. Awe,et al.  Physics Basis and Progress for a Translating FRC for MTF , 2008 .

[4]  L. Spitzer.  Physics of fully ionized gases , 1956 .

[5]  R. Maqueda,et al.  Initial results from parallel coil operation of the Coaxial Slow Source field reversed configuration device , 1993 .

[6]  J. A. Phillips,et al.  Proposal to produce large compact toroids , 1981 .

[7]  Kurt A. Polzin,et al.  Performance Optimization Criteria for Pulsed Inductive Plasma Acceleration , 2005 .

[8]  M. Tuszewski,et al.  Field reversed configurations , 1988 .

[9]  B. Novac,et al.  Studies of a very high efficiency electromagnetic launcher , 2002 .

[10]  R. K. Linford,et al.  Experimental studies of field‐reversed configuration translation , 1986 .

[11]  Carrie S. Niemela,et al.  Initial Results on an Annular Field Reversed Configuration Plasma Translation Experiment , 2008 .

[12]  R. Jahn,et al.  Physics of Electric Propulsion , 1968 .

[13]  R. Lundin,et al.  A handbook formula for the inductance of a single-layer circular coil , 1985, Proceedings of the IEEE.

[14]  Ralph H. Lovberg,et al.  The PIT MkV pulsed inductive thruster , 1993 .

[15]  Adam K. Martin,et al.  Electrical coupling efficiency of inductive plasma accelerators , 2005 .

[16]  Robert E. Dorsey,et al.  Genetic algorithms for estimation problems with multiple optima , 1995 .

[17]  Roger Smith.  Magnetic Equilibria of the Coaxial Slow Source. , 1989 .