Characterization of the electric field and gain of the 2 MeV energy analyzer (abstract)

Accurate determination of plasma potentials in the TEXT‐upgrade tokamak using the 2 MeV heavy ion beam probe requires a good understanding of detector characteristics. The detector utilized is a parallel plate electrostatic energy analyzer. A figure of merit for this analyzer is the gain, G A , which is defined as the ratio of the potential of the incident ions to the potential applied to the analyzer anode. Tests are in progress on the vertical test stand at Rensselaera) to characterize the dependence of gain on radial entrance angle, toroidal entrance angle, and toroidal position of the ion beam. Results will be used to assist with in situ calibration on the TEXT‐upgrade facility.