Electromagnetic Characterization of NEG Properties Above 200 GHz for the CLIC Damping Rings

Non-Evaporable Getter (NEG) will be used in the CLIC Electron Damping Rings (EDR) to suppress fast beam ion instabilities due to its effective pumping ability. The electromagnetic (EM) characterization of the NEG properties up to high frequencies is required for the correct impedance modeling of the Damping Ring (DR) components. The properties are determined using WR-3.4 and WR-1.5 rectangular waveguides, based on a combination of experimental measurements of the complex transmission coefficient S21 with a Vector Network Analyzer (VNA) and CST 3D EM simulations, for the frequency ranges of 220-330 GHz and 500-750 GHz. The results obtained from NEG-coated Aluminum (Al) waveguides are presented in this paper.