CERN Accelerating science

Article
Report number	CERN-ATS-2011-176
Title	Probing intensity limits of LHC-Type bunches in CERN SPS with nominal optics
Author(s)	Adrian, G (CERN) ; Allen, D (CERN) ; Andujar, O (CERN) ; Argyropoulos, T (CERN) ; Axensalva, J (CERN) ; Baldy, J (CERN) ; Bartosik, H (CERN) ; Cettour Cave, S (CERN) ; Chapuis, F (CERN) ; Comblin, JF (CERN) ; Cornelis, K (CERN) ; Cotte, D (CERN) ; Cunnington, K (CERN) ; Damerau, H (CERN) ; Delrieux, M (CERN) ; Duran-Lopez, JL (CERN) ; Esteban Mueller, J (CERN) ; Findlay, A (CERN) ; Fleuret, J (CERN) ; Follin, F (CERN) ; Freyermuth, P (CERN) ; Genoud, H (CERN) ; Gilardoni, S (CERN) ; Guerrero, A (CERN) ; Hancock, S (CERN) ; Hanke, K (CERN) ; Hans, O (CERN) ; Hazelaar, R (CERN) ; Höfle, W (CERN) ; Jensen, L (CERN) ; Kuczerowski, J (CERN) ; Le Borgne, Y (CERN) ; Maillet, R (CERN) ; Manglunki, D (CERN) ; Massot, S (CERN) ; Matli, E (CERN) ; Métral, G (CERN) ; Métral, E (CERN) ; Mikulec, B (CERN) ; Nonglaton, JM (CERN) ; Ovalle, E (CERN) ; Papaphilippou, Y (CERN) ; Pereira, L (CERN) ; Peters, F (CERN) ; Rey, A (CERN) ; Ridewood, J (CERN) ; Rumolo, G (CERN) ; Salvant, B (CERN) ; Sanchez Alvarez, JL (CERN) ; Shaposhnikova, E (CERN) ; Steerenberg, R (CERN) ; Steinhagen, R (CERN) ; Tan, J (CERN) ; Vandorpe, B (CERN) ; Veyrunes, E (CERN)
Publication	2011
Imprint	15 Sep 2011
Number of pages	3
In:	2nd International Particle Accelerator Conference, San Sebastian, Spain, 4 - 9 Sep 2011, pp.MOPS009
Subject category	Accelerators and Storage Rings
Abstract	Some of the upgrade scenarios of the high-luminosity LHC require large intensity per bunch from the injector chain. Single bunch beams with intensities of up to 3.5 to 4e11 p/b and nominal emittances were successfully produced in the PS Complex and delivered to the SPS in 2010. This contribution presents results of studies with this new intense beam in the SPS to probe single bunch intensity limitations with nominal gamma transition. In particular, the vertical Transverse Mode Coupling Instability (TMCI) threshold with low chromaticity was observed at 1.6e11 p/b for single nominal LHC bunches in the SPS. With increased vertical chromaticity, larger intensities could be injected, stored along the flat bottom and accelerated up to 450 GeV/c. However, significant losses and/or transverse emittance blow up were then observed. Longitudinal and transverse optimization efforts in the PSB, PS and SPS were put in place to minimize this beam degradation and succeeded to obtain single 2.5e11 p/b LHC type bunches with satisfying parameters at extraction of the SPS.
Copyright/License	publication: (License: CC-BY)

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