A heavy ion beam probe for Madison Symmetric Torus

A Heavy Ion Beam Probe is being developed for application on the Madison Symmetric Torus (MST). It will be used to make measurements of the plasma potential, fluctuating plasma potential, electron density, and fluctuating electron density from the core to the edge region of the plasma in MST. While information on these quantities can and has been obtained with probes inserted in the surface region, none of the above measurements have been made in the core of a hot RFP. Potential and density measurements are the standard output from a beam probe system. Less well developed are the measurements of equilibrium and fluctuating magnetic fields. Because the confining field is determined by plasma conditions, some effort has made in the design of the MST beam probe to make it possible to characterize B before, during and after the plasma discharge. Also, magnetic fluctuations play a key role RFP physics and, thus, this system will also be used to address fluctuating B once the other measurements have been established. Installation and calibration of the MST-HIBP will occur during the first six months of 1998. Regular operation is planned for the second half of the year