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Picosecond pulsed 532 nm laser system for roughening and secondary electron yield reduction of inner surfaces of up to 15 m long tubes
/ Bez, Elena (CERN ; Leipzig U.) ; Himmerlich, Marcel (CERN) ; Beaudou, Benoit (XLIM, Limoges) ; Portilla, Ana Karen Reascos (CERN) ; Wackerow, Stefan (U. Dundee) ; Rimoldi, Martino (CERN) ; Pfeiffer, Stephan (CERN) ; Wiesendanger, Markus (Zurich U.) ; Benabid, Fetah (XLIM, Limoges) ; Taborelli, Mauro (CERN) et al.
Laser-induced surface structuring is a promising method to suppress electron mulitpacting in the vacuum pipes of particle accelerators. Electrons are scattered inside the rough surface structure, resulting in a low Secondary Electron Yield (SEY) of the material. [...]
2023 - 11 p.
- Published in : Rev. Sci. Instrum. 94 (2023) 103007
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Influence of wavelength and accumulated fluence at picosecond laser-induced surface roughening of copper on secondary electron yield
/ Bez, Elena (CERN ; Leipzig U.) ; Himmerlich, Marcel (CERN) ; Lorenz, Pierre ; Ehrhardt, Martin ; Gunn, Aidan Graham (CERN) ; Pfeiffer, Stephan (CERN) ; Rimoldi, Martino (CERN) ; Taborelli, Mauro (CERN) ; Zimmer, Klaus ; Chiggiato, Paolo (CERN) et al.
Ultrashort-pulse laser processing of copper is performed in air to reduce the secondary electron yield (SEY). By UV (355 nm), green (532 nm), and IR (1064 nm) laser-light induced surface modification, this study investigates the influence of the most relevant experimental parameters, such as laser power, scanning speed, and scanning line distance (represented as accumulated fluence) on the ablation depth, surface oxidation, topography, and ultimately on the SEY. [...]
2023 - 10 p.
- Published in : J. Appl. Phys. 133 (2023) 035303
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Laser Engineered Surface Structures for Custom Design of Secondary Electron Yield
/ Bajek, David (U. Dundee) ; Wackerow, Stefan (U. Dundee) ; Sitko, Monika (CERN) ; Calatroni, Sergio (CERN) ; Girolama, Beniamino Di (CERN) ; Abdolvand, Amin (U. Dundee)
Secondary Electron Yield (SEY) [3, 5] occurs in a system when a primary electron impinges a material's surface and induces the emission of a 1
st
and potentially 2
nd
generation secondary electrons (see Figure 1, Left). The total number of secondary electrons per primary electron is the SEY. [...]
2019 - 1 p.
- Published in : 10.1109/CLEOE-EQEC.2019.8873330
In : 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference, Munich, Germany, 23 - 27 Jun 2019
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Cleaning of laser-induced periodic surface structures on copper by gentle wet chemical processing
/ Lorenz, Pierre (TROPOS, Leibniz) ; Ehrhardt, Martin (TROPOS, Leibniz) ; Lotnyk, Andriy (TROPOS, Leibniz) ; Griebel, Jan (TROPOS, Leibniz) ; Zimmer, Klaus (TROPOS, Leibniz) ; Zajadacz, Joachim (TROPOS, Leibniz) ; Himmerlich, Marcel (CERN) ; Bez, Elena (CERN ; Leipzig U.) ; Taborelli, Mauro (CERN) ; Rosenow, Steffen (Leipzig U.) et al.
•Cleaning of 365 nm LIPSS from debris of with microemulsions has been demonstrated.•Excellent debris and particles removal while maintaining the LIPSS pattern were found.•The cleaning mechanism is dominated of selective dissolution of nanomaterial and oxides. Laser-induced periodic surface structures (LIPSS) attract considerable attention due to the manifold applications enabled by these self-organised structures ranging from optical colouring to bio-mimicking or wetting effects. [...]
2024 - 10 p.
- Published in : Appl. Surf. Sci. 679 (2025) 161115
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RF characterisation of laser treated copper surfaces for the mitigation of electron cloud in accelerators
/ Krkotic, Patrick (CERN) ; Calatroni, Sergio (CERN) ; Abdolvand, Amin (Dundee U.) ; Perez Fontenla, Ana Teresa (CERN) ; Neupert, Holger (CERN) ; Himmerlich, Marcel (CERN) ; Wackerow, Stefan (Dundee U.)
In accelerator beam chambers and RF waveguides, electron cloud and multipacting can be mitigated effectively by reducing the secondary electron yield (SEY). In recent years, it has been established that laser surface structuring is a very efficient method to create a copper surface with SEY close to or even below unity. [...]
2023 - 4 p.
- Published in : JACoW IPAC2023 (2023) THPA137
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In : 14th International Particle Accelerator Conference (IPAC 2023), Venice, Italy, 7 - 12 May 2023, pp.THPA137
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Efficient Combination of Surface Texturing and Functional Coating for Very Low Secondary Electron Yield Surfaces and Rough Nonevaporable Getter Films
/ Himmerlich, Marcel (CERN) ; Zanin, Danilo A (CERN) ; Taborelli, Mauro (CERN) ; Granadeiro Costa, Angelo Rafael (CERN) ; Costa Pinto, Pedro (CERN) ; Lain Amador, Lucia (CERN) ; Vollenberg, Wilhelmus (CERN) ; Baris, Adrienn (CERN) ; Garcia‐Tabares Valdivieso, Elisa (CERN ; Carlos III U., Madrid) ; Perez Fontenla, Ana Teresa (CERN) et al.
The formation of a fissured copper surface by picosecond pulsed laser irradiation is combined with functional coatings consisting of Ti and amorphous carbon layers or a Ti–Zr–V compound film to fabricate surfaces with the maximum of the secondary electron yield being as low as 0.4. By structural and spectroscopic analysis of the formed surfaces it is demonstrated that both coatings enclose the nanostructures generated by redeposition of metal structures from the laser-induced plasma plume, keeping the initial topography intact. [...]
2022 - 8 p.
- Published in : Advanced Materials Interfaces 10 (2022) 2201671
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Towards the Implementation of Laser Engineered Surface Structures for Electron Cloud Mitigation
/ Sitko, Monika (CERN) ; Abdolvand, Amin (Dundee U.) ; Baglin, Vincent (CERN) ; Bajek, David (Dundee U.) ; Calatroni, Sergio (CERN) ; Chiggiato, Paolo (CERN) ; Colling, Miriam (Daresbury) ; Di Girolamo, Beniamino (CERN) ; Garcia-Tabares Valdivieso, Elisa (CERN) ; Jones, Thomas (Daresbury) et al.
The LHC operation has proven that the electron cloud could be a significant limiting factor in machine performance, in particular for future High Luminosity LHC (HL-LHC) beams. Electron clouds, generated by electron multipacting in the beam pipes, leads to beam instabilities and beam-induced heat load in cryogenic systems. [...]
2018 - 4 p.
- Published in : 10.18429/JACoW-IPAC2018-TUZGBE3
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In : 9th International Particle Accelerator Conference, Vancouver, Canada, 29 Apr - 4 May 2018, pp.TUZGBE3
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Laser-induced periodic surface structuring for secondary electron yield reduction of copper: dependence on ambient gas and wavelength
/ Nivas, Jijil JJ (INFN, Naples ; Naples U. ; U. Naples (main) ; CNR-SPIN, Naples) ; Hu, Meilin (U. Naples (main)) ; Valadan, Mohammadhassan (INFN, Naples ; Naples U.) ; Salvatore, Marcella (U. Naples (main) ; Naples U.) ; Fittipaldi, Rosalba (INFN, Naples ; Naples U. ; U. Salerno (main)) ; Himmerlich, Marcel (CERN) ; Bez, Elena (CERN ; Leipzig U.) ; Rimoldi, Martino (CERN) ; Passarelli, Andrea (INFN, Naples ; Naples U.) ; Oscurato, Stefano L (U. Naples (main)) et al.
One of the main limitations for future high-performance accelerators operating with positively charged particles is the formation of an electron-cloud inside the beam vacuum chamber, giving rise to instabilities. The Secondary Electron Yield (SEY) of the beam-facing surfaces gives a measure of the mechanism which drives this phenomenon. [...]
2023 - 11 p.
- Published in : Appl. Surf. Sci. 622 (2023) 156908
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