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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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Hot electron enhanced photoemission from laser fabricated plasmonic photocathodes
/ Martinez-Calderon, Miguel (CERN) ; Groussin, Baptiste (CERN) ; Bjelland, Victoria (CERN ; Norwegian U. Sci. Tech.) ; Chevallay, Eric (CERN) ; Fedosseev, Valentin N (CERN) ; Himmerlich, Marcel (CERN) ; Lorenz, Pierre ; Manjavacas, Alejandro ; Marsh, Bruce A (CERN) ; Neupert, Holger (CERN) et al.
Photocathodes are key elements in high-brightness electron sources and ubiquitous in the operation of large-scale accelerators, although their operation is often limited by their quantum efficiency and lifetime. Here, we propose to overcome these limitations by utilizing direct-laser nanostructuring techniques on copper substrates, improving their efficiency and robustness for next-generation electron photoinjectors. [...]
2023 - 9 p.
- Published in : 10.1515/nanoph-2023-0552
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The Role of Hydrogen Incorporation into Amorphous Carbon Films in the Change of the Secondary Electron Yield
/ Bundaleski, Nenad (New Lisbon U.) ; Adame, Carolina F. (New Lisbon U.) ; Alves, Eduardo (IST, Lisbon ; Lisbon U.) ; Barradas, Nuno P. (IST, Lisbon ; Lisbon U.) ; Cerqueira, Maria F. (Minho U.) ; Deuermeier, Jonas (New Lisbon U.) ; Delaup, Yorick ; Ferraria, Ana M. (IST, Lisbon) ; Ferreira, Isabel M.M. (New Lisbon U.) ; Neupert, Holger (CERN) et al.
Over the last few years, there has been increasing interest in the use of amorphous carbon thin films with low secondary electron yield (SEY) to mitigate electron multipacting in particle accelerators and RF devices. Previous works found that the SEY increases with the amount of incorporated hydrogen and correlates with the Tauc gap. [...]
2023 - 20 p.
- Published in : Int. J. Molecular Sci. 24 (2023) 12999
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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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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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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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Secondary electron yield engineering of copper surfaces using ultra short infrared laser pulses
/ Lorenz, Pierre ; Himmerlich, Marcel (CERN) ; Ehrhardt, Martin ; Bez, Elena (CERN) ; Bogdanowicz, Karolina (CERN) ; Taborelli, Mauro (CERN) ; Zimmer, Klaus
The texturing of copper surfaces with ultrashort laser pulses leads to microscopic groove formation but results also in nanostructure development at the surface. Both structure types, micro- and nanostructures, are influenced by the laser processing parameters such as the laser power, the scanning speed, the repetition rate, and the line spacing. [...]
2022
- Published in : 10.1117/12.2609463
In : Laser-based Micro- and Nanoprocessing XVI, San Francisco, California, United States, 22 -27 Jan 2022
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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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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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