Dependence of the polytropic index of plasma on magnetic field

Abstract Determination of the polytropic index plasma in a magnetic field provides description physics ranging from laboratory Earth to black hole Universe. Accordingly, lot efforts have been devoted revealing dependence on field. A recent experiment performed nozzle reported dependency strength that changes 5/3 unity with decreasing strength. In this letter, we show does not depend if radial electric is sustained. The measured be close 2, higher than previously value, regardless change and configuration