Experimental Observation of Plasma Electron Pressure

In a magnetically supported plasma column the mechanical force parallel to the magnetic field exerted on an electrically floating balance has been measured over the range of 2 to 40 dyn. This measured force agrees with the force computed from the experimentally measured plasma electron density and the electron temperature. The large range of agreement between this measured force and the computed force implies that in this apparatus, at least, the plasma pressure is due to the electrons and it can be measured directly.