IPAC2015 - List of Authors (Yin Vallgren, C.)

Paper	Title	Page
MOPJE071	New Electron Cloud Detectors for the CERN Proton Synchrotron	476
	C. Yin Vallgren, P. Chiggiato, S.S. Gilardoni, H. Neupert, M. Taborelli CERN, Geneva, Switzerland
	Electron cloud (EC) has already been observed during normal operation of the PS using classical shielded button pick-up detectors in drift sections. In the context of the LHC Injector Upgrade (LIU project), similar measurements are also needed for the combined function magnets of the machine, where the access to the vacuum chamber is strongly limited by the presence of the yoke. Two new electron cloud detectors have been studied, developed, and installed during the Long Shutdown (LS1) in one of such magnets. The first is based on current measurement by using a shielded button-type pick-up with a special geometry to reach the bottom surface of the vacuum pipe embedded in the magnet. The second one relies on a newly developed measurement method based on detection of the photons, which are emitted by cathodoluminescence from the electron cloud impinging on the vacuum chamber walls. Part of the emitted photons is collected through a quartz window by a Micro-Channel Plate Photomultiplier Tube (MCP-PMT). First results obtained during machine development runs show the feasibility of the photon detection scheme. The results are discussed and compared with pick-up measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE071
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WEPHA003	Measurement of NEG Coating Performance Variation in the LHC after the First Long Shutdown	3100
	V. Bencini, V. Baglin, G. Bregliozzi, P. Chiggiato, R. Kersevan, C. Yin Vallgren CERN, Geneva, Switzerland
	During the Long Shutdown 1 (LS1) of the Large Hadron Collider, 90% of the Non-Evaporable Getter (NEG) coated beam pipes in the Long Straight Sections (LSS) were vented to undertake the planned upgrade and consolidation programmes. After each intervention, an additional bake-out and NEG activation were performed to reach the vacuum requirements. An analysis of the coating performance variation after the additional activation cycle has been carried out by using ultimate pressure and pressure build-up measurements. In addition, laboratory measurements have been carried out to mimic the LHC coated beam pipe behaviour. The experimental data have been compared with calculation obtained by Molflow+.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA003
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Paper

Title

Page

New Electron Cloud Detectors for the CERN Proton Synchrotron

476

C. Yin Vallgren, P. Chiggiato, S.S. Gilardoni, H. Neupert, M. Taborelli
CERN, Geneva, Switzerland

Electron cloud (EC) has already been observed during normal operation of the PS using classical shielded button pick-up detectors in drift sections. In the context of the LHC Injector Upgrade (LIU project), similar measurements are also needed for the combined function magnets of the machine, where the access to the vacuum chamber is strongly limited by the presence of the yoke. Two new electron cloud detectors have been studied, developed, and installed during the Long Shutdown (LS1) in one of such magnets. The first is based on current measurement by using a shielded button-type pick-up with a special geometry to reach the bottom surface of the vacuum pipe embedded in the magnet. The second one relies on a newly developed measurement method based on detection of the photons, which are emitted by cathodoluminescence from the electron cloud impinging on the vacuum chamber walls. Part of the emitted photons is collected through a quartz window by a Micro-Channel Plate Photomultiplier Tube (MCP-PMT). First results obtained during machine development runs show the feasibility of the photon detection scheme. The results are discussed and compared with pick-up measurements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPJE071

Export •

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

WEPHA003

Measurement of NEG Coating Performance Variation in the LHC after the First Long Shutdown

3100

V. Bencini, V. Baglin, G. Bregliozzi, P. Chiggiato, R. Kersevan, C. Yin Vallgren
CERN, Geneva, Switzerland

During the Long Shutdown 1 (LS1) of the Large Hadron Collider, 90% of the Non-Evaporable Getter (NEG) coated beam pipes in the Long Straight Sections (LSS) were vented to undertake the planned upgrade and consolidation programmes. After each intervention, an additional bake-out and NEG activation were performed to reach the vacuum requirements. An analysis of the coating performance variation after the additional activation cycle has been carried out by using ultimate pressure and pressure build-up measurements. In addition, laboratory measurements have been carried out to mimic the LHC coated beam pipe behaviour. The experimental data have been compared with calculation obtained by Molflow+.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPHA003

Export •

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