K-500 Superconducting Cyclotron Deflector High Voltage Tests

We report measurements of electrical properties of a compact electrostatic deflector and high voltage transmission line for the K-500 cyclotron. The voltage limits, sparking rates, dark current levels and the effects of conditioning are observed. The system supports the maximum required voltage and fits within the space available at the mid-plane of the superconducting magnet. Both stainless steel and titanium are suitable anode materials. A surge-limiting resistance between power supply and deflector greatly reduces spark damage to the anode surface.