IPAC2018 - List of Authors (Uythoven, J.A.)

Paper	Title	Page
MOPMF060	Safe Disposal of the LHC Beam without Beam Dump - Method and Experimental Verification	253
	M. Valette, B. Lindstrom, A. Mereghetti, R. Schmidt, M. Solfaroli, J.A. Uythoven, D. Valuch, J. Wenninger, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland
	Funding: Research supported by the HL-LHC project. In the extremely unlikely event of a non-working beam dumping system in the LHC, the 360 MJ of stored beam energy can be dissipated in the collimation system as a last mitigation measure. In such a situation, it is important to reduce the stored beam energy both quickly and at the same time as smoothly as possible in order to limit the risk of trips of critical systems, to avoid quenches of superconducting magnets (which would lead to changes of the beam trajectory and damage to the accelerator) and ultimately damage to the collimators themselves. Detailed steps and parameters have been developed and validated during two dedicated experiments with beam in the LHC. This paper summarizes the key aspects in view of the preparation of such a procedure for operational use, which will allow for the safe disposal of the full LHC beam by the operation crews.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF060
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TUPAF058	Optimization of the FCC-hh Beam Extraction System Regarding Failure Avoidance and Mitigation	850
	E. Renner, M.J. Barnes, W. Bartmann, F. Burkart, E. Carlier, L. Ducimetière, B. Goddard, T. Kramer, A. Lechner, N. Magnin, V. Senaj, J.A. Uythoven, P. Van Trappen, C. Wiesner CERN, Geneva, Switzerland
	A core part of the Future Circular Collider (FCC) study is a high energy hadron-hadron collider with a circumference of nearly 100~km and a center of mass beam energy of 100~TeV. The energy stored in one beam at top energy is 8.3~GJ, more than 20 times that of the LHC beams. Due to the large damage potential of the FCC-hh beam, the design of the beam extraction system is dominated by machine protection considerations and the requirement of avoiding any material damage in case of an asynchronous beam dump. Erratic operation of one or more extraction kickers is a main contributor to asynchronous beam dumps. The presented study shows ways to reduce the probability and mitigate the impact of erratic kicker switching. Key proposals to achieve this include layout considerations, different hardware options and alternative reaction strategies in case of erratic extraction kicker occurrence. Based on these concepts, different solutions are evaluated and an optimized design for the FCC-hh extraction system is proposed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF058
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WEPAF075	Availability Allocation to Particle Accelerators Subsystems by Complexity Criteria	2009
	O. Rey Orozko, A. Apollonio, M. Jonker, J.A. Uythoven CERN, Geneva, Switzerland
	In the early design stages of an accelerator, an effective allocation method is needed to translate an overall accelerator availability goal into availability requirements for its subsystems. During the allocation process, many factors are considered to obtain so-called ‘complexity weights', which are at the basis of the system availability allocation. Some of these factors can be measured quantitatively while other have to be assessed qualitatively. Based on our analysis of factors affecting availability, we list six criteria for complexity resulting in an availability allocation of accelerator subsystems. System experts determine the scales of factors and relationships between subsystems. In this paper, we consider four availability apportionment techniques to allocate complexity weights to subsystems. Finally, we apply this method to the Compact Linear Collider (CLIC) and we propose another application of the complexity weights to the Large Hadron Collider (LHC).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF075
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WEPAF077	Performance Evaluation of Linac4 During the Reliability Run	2016
	O. Rey Orozko, A. Apollonio, S.S. Erhard, G. Guidoboni, B. Mikulec, J.A. Uythoven CERN, Geneva, Switzerland
	Linac4 will replace Linac2 as the first element in the CERN proton injector chain from 2020 onwards, following the second LHC long shutdown (LS2). With more than three times higher energy and number of compo-nents than Linac2, beam availability is one of the main challenges of Linac4. Intended as a smooth transition from commissioning to operation, a Linac4 Reliability Run was started in July 2017 and is foreseen to last until mid-May 2018. The goal is to achieve the target availability of 95 %. This implies consolidated routine operation and identification of recurring problems. This paper introduces the schedule and operational aspects of the Linac4 Reliability Run, including the developed tools and methods for availability tracking. The paper also summarizes the lessons learned during the first period of the Linac4 Reliability Run with respect to fault tracking and provides an in-depth analysis of the failure modes and observed availability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF077
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FRXGBD1	Reliability and Availability of Particle Accelerators: Concepts, Lessons, Strategy	5014
	A. Apollonio, L. Ponce, O. Rey Orozko, R. Schmidt, A.P. Siemko, B. Todd, J.A. Uythoven, A.P. Verweij, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland
	This paper will present the results and latest status of an extensive effort to analyse and improve the reliability and availability of the LHC. After the introduction of basic concepts and definitions, the paper reviews the performance of the LHC in 2015-2017. A direct comparison of the luminosity production years 2016 and 2017 is presented, with a focus on the main differences in the observed failure modes. Based on the lessons learnt in this time window, expectations for the performance during future LHC runs are discussed. In particular, the thought process for the evaluation of the possible full energy exploitation of the LHC is described, considering relevant factors such as the expected availability loss and the risk associated to magnet training.
	Slides FRXGBD1 [7.090 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-FRXGBD1
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Paper

Title

Page

Safe Disposal of the LHC Beam without Beam Dump - Method and Experimental Verification

253

M. Valette, B. Lindstrom, A. Mereghetti, R. Schmidt, M. Solfaroli, J.A. Uythoven, D. Valuch, J. Wenninger, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland

Funding: Research supported by the HL-LHC project.
In the extremely unlikely event of a non-working beam dumping system in the LHC, the 360 MJ of stored beam energy can be dissipated in the collimation system as a last mitigation measure. In such a situation, it is important to reduce the stored beam energy both quickly and at the same time as smoothly as possible in order to limit the risk of trips of critical systems, to avoid quenches of superconducting magnets (which would lead to changes of the beam trajectory and damage to the accelerator) and ultimately damage to the collimators themselves. Detailed steps and parameters have been developed and validated during two dedicated experiments with beam in the LHC. This paper summarizes the key aspects in view of the preparation of such a procedure for operational use, which will allow for the safe disposal of the full LHC beam by the operation crews.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF060

Export •

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

TUPAF058

Optimization of the FCC-hh Beam Extraction System Regarding Failure Avoidance and Mitigation

850

E. Renner, M.J. Barnes, W. Bartmann, F. Burkart, E. Carlier, L. Ducimetière, B. Goddard, T. Kramer, A. Lechner, N. Magnin, V. Senaj, J.A. Uythoven, P. Van Trappen, C. Wiesner
CERN, Geneva, Switzerland

A core part of the Future Circular Collider (FCC) study is a high energy hadron-hadron collider with a circumference of nearly 100~km and a center of mass beam energy of 100~TeV. The energy stored in one beam at top energy is 8.3~GJ, more than 20 times that of the LHC beams. Due to the large damage potential of the FCC-hh beam, the design of the beam extraction system is dominated by machine protection considerations and the requirement of avoiding any material damage in case of an asynchronous beam dump. Erratic operation of one or more extraction kickers is a main contributor to asynchronous beam dumps. The presented study shows ways to reduce the probability and mitigate the impact of erratic kicker switching. Key proposals to achieve this include layout considerations, different hardware options and alternative reaction strategies in case of erratic extraction kicker occurrence. Based on these concepts, different solutions are evaluated and an optimized design for the FCC-hh extraction system is proposed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF058

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

WEPAF075

Availability Allocation to Particle Accelerators Subsystems by Complexity Criteria

2009

O. Rey Orozko, A. Apollonio, M. Jonker, J.A. Uythoven
CERN, Geneva, Switzerland

In the early design stages of an accelerator, an effective allocation method is needed to translate an overall accelerator availability goal into availability requirements for its subsystems. During the allocation process, many factors are considered to obtain so-called ‘complexity weights', which are at the basis of the system availability allocation. Some of these factors can be measured quantitatively while other have to be assessed qualitatively. Based on our analysis of factors affecting availability, we list six criteria for complexity resulting in an availability allocation of accelerator subsystems. System experts determine the scales of factors and relationships between subsystems. In this paper, we consider four availability apportionment techniques to allocate complexity weights to subsystems. Finally, we apply this method to the Compact Linear Collider (CLIC) and we propose another application of the complexity weights to the Large Hadron Collider (LHC).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF075

Export •

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

WEPAF077

Performance Evaluation of Linac4 During the Reliability Run

2016

O. Rey Orozko, A. Apollonio, S.S. Erhard, G. Guidoboni, B. Mikulec, J.A. Uythoven
CERN, Geneva, Switzerland

Linac4 will replace Linac2 as the first element in the CERN proton injector chain from 2020 onwards, following the second LHC long shutdown (LS2). With more than three times higher energy and number of compo-nents than Linac2, beam availability is one of the main challenges of Linac4. Intended as a smooth transition from commissioning to operation, a Linac4 Reliability Run was started in July 2017 and is foreseen to last until mid-May 2018. The goal is to achieve the target availability of 95 %. This implies consolidated routine operation and identification of recurring problems. This paper introduces the schedule and operational aspects of the Linac4 Reliability Run, including the developed tools and methods for availability tracking. The paper also summarizes the lessons learned during the first period of the Linac4 Reliability Run with respect to fault tracking and provides an in-depth analysis of the failure modes and observed availability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF077

Export •

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

FRXGBD1

Reliability and Availability of Particle Accelerators: Concepts, Lessons, Strategy

5014

A. Apollonio, L. Ponce, O. Rey Orozko, R. Schmidt, A.P. Siemko, B. Todd, J.A. Uythoven, A.P. Verweij, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland

This paper will present the results and latest status of an extensive effort to analyse and improve the reliability and availability of the LHC. After the introduction of basic concepts and definitions, the paper reviews the performance of the LHC in 2015-2017. A direct comparison of the luminosity production years 2016 and 2017 is presented, with a focus on the main differences in the observed failure modes. Based on the lessons learnt in this time window, expectations for the performance during future LHC runs are discussed. In particular, the thought process for the evaluation of the possible full energy exploitation of the LHC is described, considering relevant factors such as the expected availability loss and the risk associated to magnet training.

Slides FRXGBD1 [7.090 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-FRXGBD1

Export •

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