Abstract: An insulator that has a helical protrusion spiraling around the shaft is disclosed. A lip is disposed on the distal end of the helical protrusion, creating regions on the shaft that are shielded from material deposition by the lip. By proper sizing of the threads, the helical protrusion and the lip, the line-of-sight to the interior wall of the shaft can be greatly reduced. This results in longer times before failure. This insulator may be used in an ion implantation system to physically and electrically separate two components.