The final plan with the system is to measure the spacial distribution of ion bombardment on the grid surface vs elevation angle along the grid and spatial distribution of plasma density at the center of the grid.
The coolant flow through the grid will maintain the grid surface at a constant temperature, a copper ion collector array will be mounted on the grid surface; this will consist of an array of small copper segments mounted to the grid with a standoff of known thermal conductivity, the collector to grid temperature difference will them be proportional to the heat flux flowing through the standoff. Knowing grid surface temperature and collector temperature at different angles, the variation in ion flux to the grid vs position may be determined.
Plasma density distribution will be determined by back-illuminating the plasma with a pulsed CO2 laser genlocked to the thermal camera's vsync pulse in the NTSC video signal. The signal will also trigger an LC pulse forming network to pulse the plasma to high enough density to exceed the density cutoff of the laser beam (if possible) or diffuse the beam as it travels through the plasma density gradient, which will allow some determination of density contours in the plasma.
ZnSe viewport
