A Large-Format Imaging Optics System for Fast Neutron Radiography

Fundamental power couplers for superconducting accelerator applications like the ILC are complicated transmission line assemblies that must simultaneously accommodate demanding RF power, cryogenic, and cleanliness constraints. When these couplers are RF conditioned, the observed response is an aggregate of all the parts of the coupler and the specific features that dominate the conditioning response are hard to determine. To better understand and characterize RF conditioning phenomena toward improving performance and reducing conditioning time, a high-power coupler component test stand has been built at SLAC. Operating at 1.3 GHz, this test stand was designed to measure the conditioning behavior of select components of the TTFIII coupler independently, including outer-conductor bellows, tube transitions, copper plating, surface preparations, and cold window geometries and coatings. A description of the test stand, the measurement approach, and a summary of the results obtained so far are presented.