IPAC2017 - List of Authors (Pojer, M.)

Paper	Title	Page
MOPAB009	Decomposition of Beam Losses at LHC	88
	B. Salvachua, D. Mirarchi, M. Pojer, S. Redaelli, R. Rossi, G. Valentino, M. Wyszynski CERN, Geneva, Switzerland
	The LHC collimation system provides betatron cleaning and off-momentum cleaning in two different locations of the LHC ring. In the betatron cleaning area, three primary collimators cut the primary halo in horizontal, vertical and skew planes. The beam loss monitors located downstream each of these collimators can be used to diagnose the main plane of loss. We present here a method to identify these beam losses at the LHC and decompose them as a linear combination of loss scenarios using singular value decomposition to calculate Moore-Penrose pseudoinverse of the scenario matrix. This matrix has been used to evaluate the type of beam losses in different stages of the LHC cycle.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB009
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WEPIK030	Experimental Validation of the Achromatic Telescopic Squeezing Scheme at the LHC	2992
	S.D. Fartoukh, R. Bruce, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, E.H. Maclean, L. Malina, A. Mereghetti, D. Mirarchi, T. Persson, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, P.K. Skowroński, M. Solfaroli, R. Tomás, D. Valuch, A. Wegscheider, J. Wenninger CERN, Geneva, Switzerland
	The Achromatic Telescopic Squeezing (ATS) [1] scheme offers new techniques to deliver unprecedentedly small beam spot size at the interaction points of the ATLAS and CMS experiments of the LHC, while perfectly controlling the chromatic properties of the corresponding optics (linear and non-linear chromaticities, off-momentum beta-beating, spurious dispersion induced by the crossing bumps). The first series of beam tests with ATS optics were achieved during the LHC Run I (2011/2012) for a first validation of the basics of the scheme at small intensity. In 2016, a new generation of more performing ATS optics was developed and more extensively tested in the machine, still with probe beams for optics measurement and correction at β^=10 cm, but also with a few nominal bunches to establish first collisions at nominal β^ (40 cm) and beyond (33 cm), and to analysis the robustness of these optics in terms of collimation and machine protection. The paper will highlight the most relevant and conclusive results which were obtained during this second series of ATS tests. [1] S. Fartoukh , Phys. Rev. ST Accel. Beams 16, 111002
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK030
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Paper

Title

Page

Decomposition of Beam Losses at LHC

88

B. Salvachua, D. Mirarchi, M. Pojer, S. Redaelli, R. Rossi, G. Valentino, M. Wyszynski
CERN, Geneva, Switzerland

The LHC collimation system provides betatron cleaning and off-momentum cleaning in two different locations of the LHC ring. In the betatron cleaning area, three primary collimators cut the primary halo in horizontal, vertical and skew planes. The beam loss monitors located downstream each of these collimators can be used to diagnose the main plane of loss. We present here a method to identify these beam losses at the LHC and decompose them as a linear combination of loss scenarios using singular value decomposition to calculate Moore-Penrose pseudoinverse of the scenario matrix. This matrix has been used to evaluate the type of beam losses in different stages of the LHC cycle.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB009

Export •

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

WEPIK030

Experimental Validation of the Achromatic Telescopic Squeezing Scheme at the LHC

2992

S.D. Fartoukh, R. Bruce, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, E.H. Maclean, L. Malina, A. Mereghetti, D. Mirarchi, T. Persson, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, P.K. Skowroński, M. Solfaroli, R. Tomás, D. Valuch, A. Wegscheider, J. Wenninger
CERN, Geneva, Switzerland

The Achromatic Telescopic Squeezing (ATS) [1] scheme offers new techniques to deliver unprecedentedly small beam spot size at the interaction points of the ATLAS and CMS experiments of the LHC, while perfectly controlling the chromatic properties of the corresponding optics (linear and non-linear chromaticities, off-momentum beta-beating, spurious dispersion induced by the crossing bumps). The first series of beam tests with ATS optics were achieved during the LHC Run I (2011/2012) for a first validation of the basics of the scheme at small intensity. In 2016, a new generation of more performing ATS optics was developed and more extensively tested in the machine, still with probe beams for optics measurement and correction at β^*=10 cm, but also with a few nominal bunches to establish first collisions at nominal β^* (40 cm) and beyond (33 cm), and to analysis the robustness of these optics in terms of collimation and machine protection. The paper will highlight the most relevant and conclusive results which were obtained during this second series of ATS tests.
[1] S. Fartoukh , Phys. Rev. ST Accel. Beams 16, 111002

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK030

Export •

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