Transverse ion temperature in an ionospheric wind tunnel

Abstract

The transverse ion temperature T_i⊥ of a collisionless plasma stream which simulates the ionospheric plasma has been measured by two independent means: a long cylindrical probe and a collimator‐collector device. Results with the long probe provide an experimental verification of the known end‐effect theories. Reliable measurements of T_i⊥ have been performed by these two methods, which are evaluated and compared. T_i⊥ can be varied by means of a negatively biased grid immersed in the plasma stream, the grid mesh being larger than about three Debye lengths. The achieved values are typical of the ionospheric conditions; T_i⊥ was the last parameter to be simulated with its actual value in ionospheric wind tunnels. Examples of cylinder wakes in such conditions are given.