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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
Fulltext: PDF;
In : 14th International Particle Accelerator Conference (IPAC 2023), Venice, Italy, 7 - 12 May 2023, pp.THPA137
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2.
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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
Fulltext: PDF;
In : 9th International Particle Accelerator Conference, Vancouver, Canada, 29 Apr - 4 May 2018, pp.TUZGBE3
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3.
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Cryogenic surface resistance of copper: Investigation of the impact of surface treatments for secondary electron yield reduction
/ Calatroni, Sergio (CERN) ; Arzeo, Marco (CERN) ; Aull, Sarah (CERN) ; Himmerlich, Marcel (CERN) ; Costa Pinto, Pedro (CERN) ; Vollenberg, Wilhelmus (CERN) ; Di Girolamo, Beniamino (CERN) ; Cruikshank, Paul (CERN) ; Chiggiato, Paolo (CERN) ; Bajek, David (U. Dundee) et al.
The surface resistance of copper samples with an amorphous carbon (a-C) coating or with laser surface structuring, the surface treatments of choice for electron cloud suppression in critical cryogenic sectors of the high-luminosity upgrade of the Large Hadron Collider (HL-LHC), has been measured for the first time at a cryogenic temperature using the quadrupole resonator at CERN. Three different frequencies of relevance for evaluating beam impedance effects, namely, 400, 800, and 1200 MHz, have been investigated. [...]
2019 - 9 p.
- Published in : Phys. Rev. Accel. Beams 22 (2019) 063101
Fulltext from Publisher: PDF;
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4.
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Morphological and Chemical Characterization of Laser Treated Surface on Copper
/ Baudin, Lucie (CERN ; U. Evry) ; Sitko, Monika (CERN) ; Garion, Cédric (CERN) ; Chiggiato, Paolo (CERN) ; Delloro, Francesco (U. Evry) ; Gaslain, Fabrice (U. Evry) ; Sennour, Mohamed (U. Evry) ; Jeandin, Michel (U. Evry) ; Bajek, David (Dundee U.) ; Wackerow, Stefan (Dundee U.) et al.
Electron multipacting and electron cloud have been identified as being the major limiting factors for the beam quality or for the cryogenic system of high-intensity positive particles accelerators. Among conditioning operational techniques and other surface structuration techniques used to decrease the Secondary Electron Yield (SEY) of surfaces, laser surface treatment is a promising method to treat in situ and at atmospheric pressure copper surface of the vacuum chamber. [...]
2019 - 7 p.
- Published in : Key Eng. Mater. 813 (2019) 254-260
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5.
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Optimization of the secondary electron yield of laser-structured copper surfaces at room and cryogenic temperature
/ Calatroni, Sergio (CERN) ; Garcia-Tabares Valdivieso, Elisa (CERN) ; Perez Fontenla, Ana Teresa (CERN) ; Taborelli, Mauro (CERN) ; Neupert, Holger (CERN) ; Himmerlich, Marcel (CERN) ; Chiggiato, Paolo (CERN) ; Bajek, David (Dundee U.) ; Wackerow, Stefan (Dundee U.) ; Abdolvand, Amin (Dundee U.)
Electron cloud (e-cloud) mitigation is an essential requirement for proton circular accelerators in order to guarantee beam stability at a high intensity and limit the heat load on cryogenic sections. Laser-engineered surface structuring is considered a credible process to reduce the secondary electron yield (SEY) of the surfaces facing the beam, thus suppressing the e-cloud phenomenon within the high luminosity upgrade of the LHC collider at CERN (HL-LHC). [...]
2020 - 10 p.
- Published in : Phys. Rev. Accel. Beams 23 (2020) 033101
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First accelerator test of vacuum components with laser-engineered surfaces for electron-cloud mitigation
/ Calatroni, Sergio (CERN) ; Garcia-Tabares Valdivieso, Elisa (CERN) ; Neupert, Holger (CERN) ; Nistor, Valentin (CERN) ; Perez Fontenla, Ana Teresa (CERN) ; Taborelli, Mauro (CERN) ; Chiggiato, Paolo (CERN) ; Malyshev, Oleg (Daresbury) ; Valizadeh, Reza (Daresbury) ; Wackerow, Stefan (Dundee U.) et al.
Electron cloud mitigation is an essential requirement for high-intensity proton circular accelerators. Among other solutions, laser engineered surface structures (LESS) present the advantages of having potentially a very low secondary electron yield (SEY) and allowing simple scalability for mass production. [...]
2017 - 12 p.
- Published in : Phys. Rev. Accel. Beams 20 (2017) 113201
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7.
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Out of focus ultrafast processing of metals for reduced secondary electron yield
/ Uren, Robin (U. Dundee) ; Din, A (U. Dundee) ; Wackerow, S (U. Dundee) ; Bez, E (CERN) ; Pfeiffer, S (CERN) ; Rimoldi, M (CERN) ; Himmerlich, M (CERN) ; Taborelli, M (CERN) ; Abdolvand, A (U. Dundee)
We have demonstrated out-of-focus ultrafast pulsed laser processing of copper with
a variable working distance, without the need for mechanical movement. This was achieved
by employing a diffractive optical element. [...]
2023 - 13 p.
- Published in : Opt. Mater. Express 13 (2023) 1228
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8.
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Role of surface microgeometries on electron escape probability and secondary electron yield of metal surfaces
/ Bajek, D (U. Dundee) ; Wackerow, S (U. Dundee) ; Zanin, D A (CERN) ; Baudin, L (CERN) ; Bogdanowicz, K (CERN) ; Valdivieso, E Garcia-Tabares (CERN) ; Calatroni, S (CERN) ; Di Girolamo, B (CERN) ; Sitko, M (CERN) ; Himmerlich, M (CERN) et al.
The influence of microgeometries on the Secondary Electron Yield (SEY) of surfaces is investigated. Laser written structures of different aspect ratio (height to width) on a copper surface tuned the SEY of the surface and reduced its value to less than unity. [...]
2020 - 8 p.
- Published in : Sci. Rep. 10 (2020) 250
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9.
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First Beam Test of Laser Engineered Surface Structures (LESS) at Cryogenic Temperature in CERN SPS Accelerator
/ Salemme, Roberto (CERN ; Euratom, St. Paul Lez Durance) ; Abdolvand, Amin (Dundee U.) ; Baglin, Vincent (CERN) ; Calatroni, Sergio (CERN) ; Chiggiato, Paolo (CERN) ; Di Girolamo, Beniamino (CERN) ; Garcia-Tabares Valdivieso, Elisa (CERN) ; Jenninger, Berthold (CERN) ; Prever-Loiri, Laurent (CERN) ; Sitko, Monika (CERN) et al.
Electron cloud mitigation is an essential requirement for accelerators of positive particles with high intensity beams to guarantee beam stability and limited heat load in cryogenic systems. Laser Engineered Surface Structures (LESS) are being considered, within the High Luminosity upgrade of the LHC collider at CERN (HL-LHC), as an option to reduce the Secondary Electron Yield (SEY) of the surfaces facing the beam, thus suppressing the electron cloud phenomenon. [...]
2018 - 4 p.
- Published in : (2018) , pp. WEPMG005
- Published in : J. Phys.: Conf. Ser. 1067 (2018) 082017
Fulltext: PDF;
In : 9th International Particle Accelerator Conference, Vancouver, Canada, 29 Apr - 4 May 2018, pp.WEPMG005
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10.
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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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