Experimental efforts at LNF to reduce secondary electron yield in particle accelerators

A common effort in most accelerator centres is to develop new technologies to produce and test beam pipe inner walls of particle accelerators with an as low as possible Secondary Electron Yield (SEY). This item, in fact, is crucial in controlling Electron Cloud formation and in reducing its effects that are well known to be a potential bottle-neck to the performances obtainable from present and future accelerators. Frascati has a longstanding experience in qualifying materials in terms of surface parameters of interest to e-cloud issues. We are routinely measuring SEY, its dependence from electron energy, temperature and scrubbing. We are about to be ready to study not only the Photo Electron Yield (PEY), but more importantly, to characterize in situ the surface chemical composition and eventual modifications occurring during electron or photon irradiation by using synchrotron radiation beamlines in construction at DAΦNE. Our experimental measurements of the relevant parameters can be also confidently compared to simulations, performed by running the EC codes, in order to elucidate the final consequences on machine performances. Such a combined characterization effort is also suggesting ways to produce low SEY materials coatings. This issue is particularly important in view of the possible construction in Italy of a Super-B high luminosity collider [1], where e-cloud issues are foreseen to be a potential bottleneck to operational machine performances.