TiN and TiZrV Thin Film as a Remedy Against Electron Cloud

Abstract

In many accelerators running positively charged beams, ionization of residual gas and secondary electron emission in the beam pipe will give rise to an electron cloud which can cause beam blow-up or the loss of the circulating beam. One solution to avoid the electron cloud is to ensure that the vacuum wall has low secondary emission yield (SEY). The SEY of thin films of TiN and sputter-deposited non-evaporable getter were measured for a variety of conditions, including the effect of recontamination in an ultra high vacuum environment. Submitted to the journal Nuclear Instruments and Methods in Physics Research AbstractIn many accelerators running positively charged beams, ionization of residual gas and secondary electron emission in the beam pipe will give rise to an electron cloud which can cause beam blow-up or the loss of the circulating beam. One solution to avoid the electron cloud is to ensure that the vacuum wall has low secondary emission yield (SEY). The SEY of thin films of TiN and sputter-deposited nonevaporable getter were measured for a variety of conditions, including the effect of recontamination in an ultra high vacuum environment.

DAΦNEOperation with Electron-Cloud-Clearing Electrodes

“…Various types of methods have been proposed, studied and experimentally verified in order to provide a solution to the e-cloud problems. There are two basic approaches for suppressing the ecloud effects: the first one is to modify the chamber surface properties thus reducing the Secondary Emission Yield (SEY) by the application of surface coatings [25][26][27][28][29][30][31][32][33] or by an artificial surface roughness, like grooves [32,[34][35][36][37]. Also the conditioning of the vacuum chamber surfaces by exposing it to synchrotron radiation or generated e-cloud (scrubbing) can partially reduce the SEY [30,33,38,39].…”