IPAC2017 - List of Authors (Rossi, R.)

Paper	Title	Page
MOPAB007	Status of Crystal Collimation Studies at the LHC	84
SUSPSIK008	use link to see paper's listing under its alternate paper code
	R. Rossi, O. Aberle, O.Ø. Andreassen, M.E.J. Butcher, C.A. Dionisio Barreto, I. Lamas Garcia, A. Masi, D. Mirarchi, S. Montesano, S. Redaelli, A. Rijllart, W. Scandale, P. Serrano Galvez, G. Valentino CERN, Geneva, Switzerland F. Galluccio INFN-Napoli, Napoli, Italy
	Crystal collimation is a technique that relies on highly pure bent crystals to coherently deflect beam particles - through the channeling mechanisms - onto dedicated absorbers. Standard multi-stage collimation systems for hadron beams use amorphous materials as primary collimators and might be limited by nuclear interactions and ion fragmentation that are strongly suppressed in crystals. A crystal collimation setup was installed in the betatron cleaning insertion of the Large Hadron Collider (LHC) to demonstrate with LHC beams the feasibility of this concept and to compare its performance with that of the present system. Channeling was observed for the first time with 6.5 TeV beam and and plans for further crystal collimation beam tests at the LHC are discussed. Results of these first beam tests are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB007
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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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MOPAB010	Anomaly Detection for Beam Loss Maps in the Large Hadron Collider	92
	G. Valentino University of Malta, Information and Communication Technology, Msida, Malta R. Bruce, S. Redaelli, R. Rossi, P. Theodoropoulos CERN, Geneva, Switzerland S. Jaster-Merz University of Hamburg, Hamburg, Germany
	In the LHC, beam loss maps are used to validate collimator settings for cleaning and machine protection. This is done by monitoring the loss distribution in the ring during infrequent controlled loss map campaigns, as well as in standard operation. Due to the complexity of the system, consisting of more than 50 collimators per beam, it is difficult to identify small changes in the collimation hierarchy, which may be due to setting errors or beam orbit drifts with such methods. A technique based on Principal Component Analysis and Local Outlier Factor is presented to detect anomalies in the loss maps and therefore provide an automatic check of the collimation hierarchy.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB010
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MOPIK048	Experimental Results of Crystal-Assisted Slow Extraction at the SPS	623
	M.A. Fraser, S.S. Gilardoni, B. Goddard, V. Kain, D. Mirarchi, S. Montesano, S. Petrucci, S. Redaelli, R. Rossi, W. Scandale, L.S. Stoel, F.M. Velotti CERN, Geneva, Switzerland F.M. Addesa, G. Cavoto, F. Iacoangeli INFN-Roma, Roma, Italy F. Galluccio INFN-Napoli, Napoli, Italy F. Murtas INFN/LNF, Frascati (Roma), Italy
	The possibility of extracting highly energetic particles from the Super Proton Synchrotron (SPS) by means of silicon bent crystals has been explored since the 1990's. The channelling effect of a bent crystal can be used to strongly deflect primary protons and eject them from the synchrotron. Many studies and experiments have been carried out to investigate crystal channelling effects. The extraction of 120 and 270 GeV proton beams has already been demonstrated in the SPS with dedicated experiments located in the ring. Presently in the SPS, the UA9 experiment is performing studies to evaluate the possibility to use bent silicon crystals to steer particle beams in high energy accelerators. Recent studies on the feasibility of extraction from the SPS have been made using the UA9 infrastructure with a longer-term view of using crystals to help mitigate slow extraction induced activation of the SPS. In this paper, the possibility to eject particles into the extraction channel in LSS2 using the bent crystals already installed in the SPS is presented. Details of the concept, simulations and measurements carried out with beam are presented, before the outlook for the future is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK048
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Paper

Title

Page

MOPAB007

Status of Crystal Collimation Studies at the LHC

84

SUSPSIK008

use link to see paper's listing under its alternate paper code

R. Rossi, O. Aberle, O.Ø. Andreassen, M.E.J. Butcher, C.A. Dionisio Barreto, I. Lamas Garcia, A. Masi, D. Mirarchi, S. Montesano, S. Redaelli, A. Rijllart, W. Scandale, P. Serrano Galvez, G. Valentino
CERN, Geneva, Switzerland
F. Galluccio
INFN-Napoli, Napoli, Italy

Crystal collimation is a technique that relies on highly pure bent crystals to coherently deflect beam particles - through the channeling mechanisms - onto dedicated absorbers. Standard multi-stage collimation systems for hadron beams use amorphous materials as primary collimators and might be limited by nuclear interactions and ion fragmentation that are strongly suppressed in crystals. A crystal collimation setup was installed in the betatron cleaning insertion of the Large Hadron Collider (LHC) to demonstrate with LHC beams the feasibility of this concept and to compare its performance with that of the present system. Channeling was observed for the first time with 6.5 TeV beam and and plans for further crystal collimation beam tests at the LHC are discussed. Results of these first beam tests are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB007

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

MOPAB010

Anomaly Detection for Beam Loss Maps in the Large Hadron Collider

92

G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta
R. Bruce, S. Redaelli, R. Rossi, P. Theodoropoulos
CERN, Geneva, Switzerland
S. Jaster-Merz
University of Hamburg, Hamburg, Germany

In the LHC, beam loss maps are used to validate collimator settings for cleaning and machine protection. This is done by monitoring the loss distribution in the ring during infrequent controlled loss map campaigns, as well as in standard operation. Due to the complexity of the system, consisting of more than 50 collimators per beam, it is difficult to identify small changes in the collimation hierarchy, which may be due to setting errors or beam orbit drifts with such methods. A technique based on Principal Component Analysis and Local Outlier Factor is presented to detect anomalies in the loss maps and therefore provide an automatic check of the collimation hierarchy.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB010

Export •

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

MOPIK048

Experimental Results of Crystal-Assisted Slow Extraction at the SPS

623

M.A. Fraser, S.S. Gilardoni, B. Goddard, V. Kain, D. Mirarchi, S. Montesano, S. Petrucci, S. Redaelli, R. Rossi, W. Scandale, L.S. Stoel, F.M. Velotti
CERN, Geneva, Switzerland
F.M. Addesa, G. Cavoto, F. Iacoangeli
INFN-Roma, Roma, Italy
F. Galluccio
INFN-Napoli, Napoli, Italy
F. Murtas
INFN/LNF, Frascati (Roma), Italy

The possibility of extracting highly energetic particles from the Super Proton Synchrotron (SPS) by means of silicon bent crystals has been explored since the 1990's. The channelling effect of a bent crystal can be used to strongly deflect primary protons and eject them from the synchrotron. Many studies and experiments have been carried out to investigate crystal channelling effects. The extraction of 120 and 270 GeV proton beams has already been demonstrated in the SPS with dedicated experiments located in the ring. Presently in the SPS, the UA9 experiment is performing studies to evaluate the possibility to use bent silicon crystals to steer particle beams in high energy accelerators. Recent studies on the feasibility of extraction from the SPS have been made using the UA9 infrastructure with a longer-term view of using crystals to help mitigate slow extraction induced activation of the SPS. In this paper, the possibility to eject particles into the extraction channel in LSS2 using the bent crystals already installed in the SPS is presented. Details of the concept, simulations and measurements carried out with beam are presented, before the outlook for the future is discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK048

Export •

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