IPAC2015 - List of Authors (Bartova, B.)

Paper	Title	Page
WEPHA019	Development and Production of Non-evaporable Getter Coatings for MAX IV	3145
	P. Costa Pinto, B. Bártová, B. Holliger, S. Marques Dos Santos, V. Nistor, A. Sapountzis, M. Taborelli, I. Wevers CERN, Geneva, Switzerland J. Ahlbäck, E. Al-Dmour, M.J. Grabski, C. Pasquino MAX-lab, Lund, Sweden
	MAX IV is presently under construction at Lund, Sweden, and the first beam for the production of synchrotron radiation is expected to circulate in 2016. The whole set of 3-GeV ring beam pipes is coated with Ti-Zr-V Non Evaporable Getter (NEG) thin film in order to fulfil the average pressure requirement of 1x10^-9 mbar, despite the compact magnet layout and the large aspect ratio of the vacuum chambers. In this work, we present the optimisations of the coating process performed at CERN to coat different geometries and mechanical assembling used for the MAX IV vacuum chambers; the morphology of the thin films is analysed by Scanning Electron Microscopy; the composition and thickness is measured by Energy Dispersive X-ray analysis; the activation of the NEG thin film is monitored by X-ray Photoemission Spectroscopy; the vacuum performance of the coated beam pipes is evaluated by the measurement of hydrogen sticking coefficient. The results of the coating production characterisation for the 84 units coated at CERN are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPHA022	Characterization of Nb Coating in HIE-ISOLDE QWR Superconducting Accelerating Cavities by means of SEM-FIB and TEM	3155
	B. Bártová, S. Calatroni, A. Sublet, M. Taborelli CERN, Geneva, Switzerland A.B. Aebersold, D.T.L. Alexander, M. Cantoni EPFL, Lausanne, Switzerland
	The Quarter Wave Resonators (QWR) high-β cavities (0.3m diameter and 0.9m height) are made from OFE 3D-forged copper and are coated by DC-bias diode sputtering with a thin superconducting layer of niobium. The Nb film thickness, morphology, purity and quality are critical parameters for RF performances of the cavity. They have been investigated in a detailed material study. The coating structure at different positions along a test cavity was observed by cross-section imaging using SEM-FIB instrument. The samples from the top of the cavity showed presence of unexpected porosities, whose volume was investigated using FIB tomography. TEM lamella was prepared for two samples (top part and inner conductor of the cavity) to study in detail the grain orientation in the coating, its chemical composition and structure. The 14-layer structure in thick coating was indeed evidenced by the TEM analysis. Chemical mapping revealed the presence of a few nm in size copper precipitates close to the Nb/Cu interface and a passivating oxide layer of 10 nm thickness on top of the coating and around porosities. However no impurities or interface layer along the coating profile were present.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA022
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Development and Production of Non-evaporable Getter Coatings for MAX IV

3145

P. Costa Pinto, B. Bártová, B. Holliger, S. Marques Dos Santos, V. Nistor, A. Sapountzis, M. Taborelli, I. Wevers
CERN, Geneva, Switzerland
J. Ahlbäck, E. Al-Dmour, M.J. Grabski, C. Pasquino
MAX-lab, Lund, Sweden

MAX IV is presently under construction at Lund, Sweden, and the first beam for the production of synchrotron radiation is expected to circulate in 2016. The whole set of 3-GeV ring beam pipes is coated with Ti-Zr-V Non Evaporable Getter (NEG) thin film in order to fulfil the average pressure requirement of 1x10^-9 mbar, despite the compact magnet layout and the large aspect ratio of the vacuum chambers. In this work, we present the optimisations of the coating process performed at CERN to coat different geometries and mechanical assembling used for the MAX IV vacuum chambers; the morphology of the thin films is analysed by Scanning Electron Microscopy; the composition and thickness is measured by Energy Dispersive X-ray analysis; the activation of the NEG thin film is monitored by X-ray Photoemission Spectroscopy; the vacuum performance of the coated beam pipes is evaluated by the measurement of hydrogen sticking coefficient. The results of the coating production characterisation for the 84 units coated at CERN are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPHA022

Characterization of Nb Coating in HIE-ISOLDE QWR Superconducting Accelerating Cavities by means of SEM-FIB and TEM

3155

B. Bártová, S. Calatroni, A. Sublet, M. Taborelli
CERN, Geneva, Switzerland
A.B. Aebersold, D.T.L. Alexander, M. Cantoni
EPFL, Lausanne, Switzerland

The Quarter Wave Resonators (QWR) high-β cavities (0.3m diameter and 0.9m height) are made from OFE 3D-forged copper and are coated by DC-bias diode sputtering with a thin superconducting layer of niobium. The Nb film thickness, morphology, purity and quality are critical parameters for RF performances of the cavity. They have been investigated in a detailed material study. The coating structure at different positions along a test cavity was observed by cross-section imaging using SEM-FIB instrument. The samples from the top of the cavity showed presence of unexpected porosities, whose volume was investigated using FIB tomography. TEM lamella was prepared for two samples (top part and inner conductor of the cavity) to study in detail the grain orientation in the coating, its chemical composition and structure. The 14-layer structure in thick coating was indeed evidenced by the TEM analysis. Chemical mapping revealed the presence of a few nm in size copper precipitates close to the Nb/Cu interface and a passivating oxide layer of 10 nm thickness on top of the coating and around porosities. However no impurities or interface layer along the coating profile were present.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA022

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)