Keywords

instability, self-shielding, dicotron mode, non-neutral plasmas, Malmberg-Penning traps, plasma ends, kinetic effect

Abstract

The "self-shielding" m = 1 diocotron mode in Malmberg-Penning traps has been known for over a decade to be unstable for finite length non-neutral plasmas with hollow density profiles. Early theoretical efforts were unsuccessful in accounting for the exponential growth and/or the magnitude of the growth rate. Recent theoretical work has sought to resolve the discrepancy either as a consequence of the shape of the plasma ends or as a kinetic effect resulting from a modified distribution function as a consequence of the protocol used to form the hollow profiles in experiments. Both of these finite length mechanisms have been investigated in selected test cases using a three-dimensional particle-in-cell code that allows realistic treatment of shape and kinetic effects. A persistent discrepancy of a factor of 2-3 remains between simulation and experimental values of the growth rate. Simulations reported here are more in agreement with theoretical predictions and fail to explain the discrepancy.

Original Publication Citation

Mason, Grant W. and Ross L. Spencer."Simulations of the instability of the m = 1 self-shielding diocotron mode in finite-length non-neutral plasmas." Physics of Plasmas 9 (22): 3217-3224.

Document Type

Peer-Reviewed Article

Publication Date

2002-08-01

Permanent URL

http://hdl.lib.byu.edu/1877/1360

Publisher

AIP

Language

English

College

Physical and Mathematical Sciences

Department

Physics and Astronomy

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