Copper plating the Ground Test Accelerator RFQ

The copper-plating process for the Ground Test Accelerator (GTA) radio frequency quadrupole (RFQ) vanes required a full development program and tight quality control procedures. The copper plating development program utilized full size RFQ major and minor vane mockups to develop plating fixturing and to establish the plating parameters necessary to meet the GTA RFQ plating specifications. After several modifications to the fixturing and plating processes, the mockup vanes were copper plated to GTA specifications and the actual GTA RFQ could then be copper plated. This development technique, using full-size mockups for establishing reliable and accurate plating fixtures and proven plating processes, is the key to success for copper-plating any special piece of technical and expensive hardware. This paper discusses the GTA RFQ copper-plating critical issues; the plating-fixture development; the copper-plating processes; RFQ plating specifications as they apply to thickness, uniformity, and adhesion; and the quality assurance procedures