IMPROVED OPTICAL TOMOGRAPHY DEVICE

We report the development of an improved optical tomography diagnostic which measures the velocity-space distribution of a laboratory plasma in two dimensions. The new device is capable of imaging plasma distri butions over a wider range of magnetic fields and plasma column diamet ers than the previous design, while minimizing the risk of misdiagnosi s due to perturbations caused by inserting the device in the plasma. C omputer-aided control of the diagnostic allows a greater number of sin gle-dimensional scans to be collected in a shorter amount of time, res ulting in increased resolution of the reconstructed image while freein g up more time for the user to perform the experiment. Recent data usi ng the new device are presented to show improvement of resolution gain ed by doubling the number of total scans. Finally, we present a method to identify velocity-space nonuniformities without the need to recons truct a complete image.