Amorphous Carbon Coating Material with Low Secondary Electron Yield for High Energy Particle Accelerator

We addressed the electron cloud problem in modern high-energy and high-luminosity particle accelerators. The amorphous carbon (a-C) coatings, with low secondary electron yield (SEY) in ultra-high vacuum, were deposited by DC magnetron sputtering on the stainless steel substrate installed on the inner wall of a pipe (Φ86 mm×1000 mm) to be used as the storage ring in the particle accelerator. The influence of the microstructures of the aC coatings and dose of electron beam on SEY was investigated with scanning electron microscopy and X-ray photoelectron spectroscopy. The results show that normally impacted by an e-beam at a dose of 1×10^-8 C/mm^-2, SEY of the highly pure and fairly rough a-C coatings with strong interfacial adhesion was estimated to be 1. 132. We suggest that a-C film may be a promising surface modification material to suppress electron cloud and to enhance the particle beam stability.