Comment on [“Plasma Physics: An Introductory Course”] Book Review

Authors


Abstract

The review of Plasma Physics: An Introductory Course [Eos 76, p.53, 1995] is marred by a serious inaccuracy and several misleading omissions. The review reports, erroneously, that chapter 9 part 1 states that“…electric fields due to space charge separation play no role in charged particle acceleration at shocks or in the auroral region.” The fact is that the chapter describes and advocates a mechanism (Landau damping) by which acceleration at these locations is caused by electrostatic waves where “the motion of the electrostatic barrier…is essential for energy transfer.”

The statement to which the review refers carries the crucial, and twice explicitly mentioned, qualification that the space-charge electric field is static, relative to particle transit time, and, therefore, effectively conservative. When properly represented, therefore, the statement is seen to follow directly from one of the basic principles of physics—the conservative nature of fields due to central forces, from which it is clear that it is no more possible for energy to be delivered by unchanging (in the observing frame) electrostatic fields than it is possible for an engine to run on gravity. In citing the simulation literature as offering strong evidence against this “opinion,” as it is described, the review neglects to mention that the chapter challenges such evidence with the prediction that all models claiming to accelerate particles by unchanging electrostatic fields will be found to contain a major flaw, such as equipotentials that are not closed surfaces.

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