Sweep System Design for a Heavy Ion Beam Probe on MST

The sweep system for the HIBP (Heavy Ion Beam Probe) on the Madison Symmetric Torus is described. The two components of the system are the primary sweep optics and secondary collimation plates. Key issues in the sweep system design are the small entrance and exit ports available on MST, the signi cant toroidal beam motion induced by the strong poloidal magnetic eld and the excessive current loading due to plasma and UV. The design accommodates these issues using a crossover sweep plate design in two dimensions for the primary beam as well as two dimensional sweeping on the secondary beam. The primary beam sweep design results in a sweep range of 20 degrees in one direction and 5 degrees in the perpendicular direction. The secondary beam sweep design results in entrance angles to the energy analyzer of < 3 degrees in radial and zero degree in toroidal directions. The procedure for calculating sweep performance including fringe elds, a system for active trajectory control, and initial experiments on plasma and UV loading are also discussed.