Regensburg 2022 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 13: Nanostructures at Surfaces 2
O 13.9: Vortrag
Montag, 5. September 2022, 17:00–17:15, S052
Processing copper surfaces with ultrashort laser pulses to reduce secondary electron yield — •Elena Bez1,2, Marcel Himmerlich1, Ana Karen Reascos Portilla1, Pierre Lorenz3, Klaus Zimmer3, Mauro Taborelli1, and André Anders2,3 — 1CERN, European Organization for Nuclear Research, 1211 Geneva 23, Switzerland — 2University of Leipzig, Linnéstr. 5, 04103 Leipzig, Germany — 3Leibniz Institute of Surface Engineering (IOM), Per- moserstr. 15, 04318 Leipzig, Germany
Ultrashort-pulse laser processing in air is employed to engrave micro- and nanostructures on copper surfaces aiming to reduce secondary electron emission. Parameters such as the laser power and scanning speed are varied to investigate their influence on the resulting structures. The morphology, as well as the chemical composition of the laser-treated surfaces, are analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. At low power and high scanning speed, only slight changes to the surface topography occur, whereas compact, cauliflower-like nanostructures and micrometer deep trenches are generated at high power and low scanning speed. The higher the accumulated laser fluence, the more material is ablated and the more oxidized particles are redeposited. A clear correlation exists between the accumulated fluence for processing with 355, 532 and 1064 nm photons, and the resulting secondary electron yield of the surface. Its maximum can be reduced from 2.2 to 0.7. Mastering these dependencies helps to develop a system that enables laser processing of beam pipes of selected magnets in the Large Hadron Collider.