Comment on ``Rotation Velocities and Radial Electric Field in the Plasma Edge''

TL;DR

This paper critiques a previous plasma physics study, highlighting an inconsistency in electrostatic potential treatment and emphasizing that the electrostatic field should vanish in a neutral, conducting fluid model.

Contribution

It identifies a fundamental inconsistency in the electrostatic potential treatment in Stacey's plasma edge rotation study and clarifies the implications from a field-theoretic perspective.

Findings

The original calculation contains an inconsistency in electrostatic potential treatment.

Electrostatic field must vanish in a neutral, conducting fluid model.

Highlights the importance of consistent electrostatic potential assumptions.

Abstract

The calculation presented in "Rotation Velocities and Radial Electric Field in the Plasma Edge" by W. M. Stacey [Contrib. Plasma Phys. 46, (2006)] contains an inconsistent treatment of the electrostatic potential. Comparing the expressions for the potential associated with the radial electrostatic field with that associated with the poloidal electrostatic field reveals the inconsistency. A field-theoretic perspective implies that the electrostatic field must vanish in a model based upon the physics of a neutral, conducting fluid.