  In a recent paper (Phys. Plasmas 25, 061203, 2018), the authors have
presented the analysis of the electric ion drift velocity experienced by heavy
ions created in a plasma submitted to a low magnetic field. Unfortunately, they
have used the classical ExB drift formula that is valid only in slab geometry.
The authors have not taken into account that the cylindrical geometry induces a
slow electric drift of the ions around the axis of the column. Moreover, the
low magnetization of the ions induces a Larmor radius that is larger than the
diameter of the plasma column. The movement of the ions immediately after their
creation is parallel to the local electric field, not perpendicular as
indicated by the authors. Most often the ions are neutralized before
experiencing the electric drift calculated along the classical guiding center
theory. This has not been taken into account carefully by the authors so that
the theoretical analysis of the Laser Induced Fluorescence measurements
presented in this paper is clearly invalid.

Plasma Physics