Titanium-nitride coated anodized aluminum and oxide coated aluminum foil radio frequency windows and secondary electron emission.

摘要

Radio frequency windows are used in various applications such as particle accelerators, vacuum systems, couplers, and communication electronics. Aluminum radio frequency windows are widely preferred because of their useful qualities such as their thermal stability, low out-gassing rate, mechanical strength, and dielectric properties. The problem with aluminum is its high multipactor susceptibility when high electric fields are applied in radio frequency applications. The application of thin film coatings of titanium nitride by varied means, have shown a reduction of multipactor. Coatings of oxygen on annealed aluminum foil radio frequency windows of less than nominal purity have yielded useful results as well. Although there are various other methods of reducing multipactor, thin film coatings are the most efficient and cost effective to implement. Analysis of titanium nitride pulsed laser deposited aluminum windows anodized for different times and annealed oxide adsorped thin films on an aluminum foil window for different times was done to examine their multipactor susceptibility and relative composition. The titanium nitride coated aluminum windows were shown to suppress multipactor quite well even after sputtering through layers of thin film. After successive sputtering and substantial digging, the thin film titanium nitride anodized aluminum windows revealed good structure, even distribution of material, and no penetration to the Al2O3 layer. The oxide thin film layers on the aluminum foil showed promise after a substantial layer depth was reached. The study has demonstrated that the Duarte (CIMAV) process is sound when multipactor is concerned and Al 2O3 coatings on less than pure aluminum foil is as well quite effective at suppressing multipactor at room temperatures.