Plasma Diagnostics Using a Spheromak Device*

                 The properties of plasmas created in a spheromak device (STPX) are measured and the behavior of the device is characterized under different operating conditions.  An electron gun has been used to inject a transient Argon plasma (~5 ms) into the spheromak chamber, a steady state plasma has been created using electrodes, and the plasma density, temperature and electric potential under these two operating conditions are estimated.  The various diagnostics available include Langmuir probe, three-axis magnetic field probe, spectrometer, ccd camera, photodiode, laser, charge collector as well as current and voltage monitors.  Analysis of experimental results as well as supporting simulations will be presented.  Modeling of the self-organized configuration of the spheromak plasma, which is similar to certain astrophysical events, will be discussed.