Efficient electron cloud mitigation with novel low SEY laser-engineered surface structures (LESS)

by Prof. Amin Abdolvand (School of Engineering, Physics and Mathematics, University of Dundee, UK), Oleg Malyshev (STFC Daresbury Laboratory, Warrington, UK)

Thursday 26 Feb 2015, 14:15 → 15:30 Europe/Zurich

30/7-018 - Kjell Johnsen Auditorium (CERN)

Developing a surface with a low Secondary Electron Yield (SEY or δ) is one of main techniques for mitigating electron cloud and beam-induced electron multipacting in high-energy charged particle accelerators. 

This talk will concentrate on the newly-developed rapid laser texturing of metal surfaces. The generation of “black” metals and fabrication of specialised surface profiles can lead to exploitation of the structured surfaces in general photonics and in particle accelerators. In particular, this treatment leads to the formation of highly organised surface microstructures with δ < 0.8 on as-received Cu, Al and Stainless steel, the most common materials for beam vacuum chambers and components. The SEY can be further reduced to δ < 0.6 by bakeout and/or electron bombardment. The surface with LESS does not affect vacuum properties (outgassing, photon and electron stimulated desorption) and has demonstrated less than a factor of 2 increase in surface resistance. We will discuss correlations between the parameters and conditions used for the laser treatment, systematic analysis of surface composition and chemistry (using XPS), surface topography (using SEM and AFM), and SEY measurements with primary electron energies ranging between 50 eV and 1 keV. 

 

ATS Seminars Organisers: H. Burkhardt (BE), M. Modena (TE), T. Stora (EN)

Coffee / tea will be served after the seminar in room 30/7-012

Presentation Amin_CERN_26_Feb_2015.pdf CERN_talk_26-Feb-2015-.pdf