International Review of the HL-LHC Collimation System

11 Feb 2019, 08:15 → 12 Feb 2019, 17:30 Europe/Zurich

30/7-018 - Kjell Johnsen Auditorium (CERN)

Mandate

The main objective is to review the collimation system of HL-LHC in view of the LHC Run1 and Run2 experience and the suitability for installation in the LHC. The review will examine the upgrades in the experimental and cleaning insertion regions as well as the new cleaning systems in the dispersion suppressor regions of P7 and P2.

Review Panel

Ralph Assmann (DESY), Wolfram Fischer (BNL), Mike Lamont (CERN), Mike Seidel (PSI, Chair), Alban Sublet (CERN), Walter Venturini (CERN).

Scientific secretary: Alessio Mereghetti | S. Redaelli: link person for the HL-LHC Collimation upgrade (WP5)

Date and Place: 11th – 12th February 2019 at CERN (Auditorium TE 30-7-018).

Format

One and a half day presentations and discussions, followed by an executive meeting of the committee and a close-out on the second day. Following the close-out by the review chair, the committee is asked to compile a short report with findings, comments and recommendations within one month. The report will be delivered to O. Brüning, HL-LHC Deputy Project Leader and L. Rossi, HL-LHC Project Leader.

Charges: See attached document.

Collimation_2019_report_final_rev.pdf

Collimation_2019_Review_Minutes_final.pdf

HL-Collimation-Review-2019-Charges-10-00.pdf

Monday, 11 February

08:15 → 08:45 Executive Session (closed session AM)

08:45 → 09:30 Introductory Session

08:45 Welcome, introduction and mandate

• Detailed introduction of upgrade plans
• Review of HL-LHC parameters
• Brightness frontier in Run III following LIU upgrade

Speaker: Oliver Bruning (CERN)

09:00 Collimation upgrade plans

• Detailed introduction of upgrade plans
• Definition of timeline for the WP5 upgrade: LS2 and LS3 plans
• Recap. of the planned consolidation activities, impacts for the HL goals
• Introduce the new design features relevant for HL: BPM collimators, new jaw design
• Recap. status and plans for hollow e-lenses and crystals
• Recap. of the last technical review for HL-LHC at Chamonix 2018 for collimation

Speaker: Stefano Redaelli (CERN)

SRedaelli_2019-02-11.pdf

09:30 → 11:00 Session 1: Review of the operational experience in Run I and Run II

09:30 Overview of present collimation performance (20+10)

• Evolution of settings and protected aperture for small beta*
• Cleaning performance throughout the years
• Performance of IR cleaning (incoming and outgoing)
• Relevant system faults and HL-LHC protected aperture
• System failures, availability and sources of downtime
• Review of beam loss cases inducing damage

Speaker: Roderik Bruce (CERN)

2019.02.11--HL_collimation_review_performance.pdf

2019.02.11--HL_collimation_review_performance.pptx

10:00 Beam losses, lifetime and operational experience at 6.5 TeV (20+10)

• Review beam losses and lifetime for protons and ions
• Stability and reproducibility: collimation settings
• Stability and reproducibility: orbit and optics
• Tail population measurements
• Experience with beam failures damaging the collimator

Speaker: Belen Maria Salvachua Ferrando (CERN)

salvachua-2019-02-11.pdf

salvachua-2019-02-11.pptx

10:30 Performance of new designs deployed in Run II and plans for Run III (20+10)

• New jaw design and performance of BPM collimators
• Operational performance of the TCSPM prototype in 2017-2018
• Software improvements and performance in Run II: alignment and BPM interlocks (including machine learning)
• Prospect for further improvements, including machine learning
• Recap. of Run III layouts

Speaker: Alessio Mereghetti (CERN)

2019-02-11_AM.pdf

2019-02-11_AM.pptx

11:00 → 11:30 Group picture and Coffee break

11:30 → 13:00 Session 2: Upgrade plans - performance and needs

11:30 Cleaning upgrades in the dispersion suppressors (20+10)

• Review technical solutions for DS around IR7 and IR2
• Studies of different locations for IR7 and final layouts
• TCLD design: settings and material choices. Functional specifications
• Review key/critical points in the ECR (installation, safety, transport…)

Speaker: Anton Lechner (CERN)

2019_11_02_dsupgradeshl.pdf

12:00 Quench performance and assumptions: simulations and beam tests (20+10)

• Collimation quench tests with protons: can we quench with proton beams?
• Collimation quench tests with ions and BFPP quench tests
• Benchmark of simulations: peak energy deposition for the different test

Speaker: Eleftherios Skordis (CERN)

2019_11_02_Coll_Review-E_Skordis_2015QuenchTestsAnalysis.pdf

2019_11_02_Coll_Review-E_Skordis_2015QuenchTestsAnalysis.pptx

12:30 Quench performance and assumptions: magnets and cryogenics (20+10)

• Quench limits and possible limitations from cryogenics
• Status of cryogenics limitations for different loss scenarios
• Comparison of present dipole and 11T dipole

Speaker: Luca Bottura (CERN)

Quench_limits_LB.pdf

Quench_limits_LB.pptx

13:00 → 14:00 Lunch break

14:00 → 16:00 Session 2: Upgrade plans - performance and needs

14:00 Operational experience with ions (20+10)

• Review of relevant aspects in ions runs
• Plans for bumps in different IRs: IR1/5 without TCLD and IR2 with TCLD (without 11T)
• Are the bump solutions robust enough for the HL-LHC
• Luminosity reach with the present upgrade scenarios
• Brief highlights from the crystal collimation tests with ion beams during Run 2

Speaker: Nuria Fuster Martinez (CERN)

HL-LHC_coll_review_ions.pdf

HL-LHC_coll_review_ions.pptx

14:30 Status of 11T dipole project (20+10)

• Overview talk from WP11: where we are and what are the plans for LS2
• Final configuration of cold masses and corrector package in new locations
• Summary of LS2’s ECRs

Speaker: Frederic Savary (CERN)

2019-02-11_IR of the HL-LHC Collimation System_FSavary_Compressed.pdf

2019-02-11_IR of the HL-LHC Collimation System_FSavary_Compressed.pptx

15:00 Impedance models, operational experience and expected limitations (20+10)

• IR7 upgrade plans in LS2 and LS3
• Experience from Run I and Run II
• Expectations for HL-LHC
• Review of beam tests with the low-impedance prototype
• Other mitigation options for impedance issues (new optics, asymmetric settings, new ATS) and drawbacks: theory and beam test results

Speaker: Elias Metral (CERN)

ImpedanceAndRelatedLimitations_HLLHCCollimationReview_11-02-19_EM.pdf

ImpedanceAndRelatedLimitations_HLLHCCollimationReview_11-02-19_EM.pptx

15:30 IR collimation upgrades – incoming beam (20+10)

• Layout for new IR1 and IR5
• Protected aperture and baseline settings
• Proposed material choices and their performance

Speakers: Hector Garcia Morales (Royal Holloway University of London (RHUL)), Roderik Bruce (CERN)

slides_layout_incoming_beam_hector_garcia.pdf

16:00 → 16:30 Coffee break

16:30 → 18:00 Session 2: Upgrade plans - performance and needs

16:30 IR collimation upgrades – outgoing beam (20+10)

• Layout for new IR1 and IR5: TCLs and masks
• DS losses at high luminosity: any limitations for proton operations?
• Status of mask specifications

Speaker: Francesco Cerutti (CERN)

collrev.pdf

collrev.pptx

17:00 Plans and goals for remote alignment and impact on collimator designs (20+10)

• Overview of the overall plans, with specific aspects for WP5
• Review tolerances and specifications
• Timeline for critical decision points

Speaker: Paolo Fessia (CERN)

Collimators_Full_remote_alignement.pdf

Collimators_Full_remote_alignement.pptx

17:30 Review of hollow e-lenses (20+10)

• Recap. previous reviews and status of baseline process
• Design overview: where we are
• Status of process for insertion into baseline

Speaker: Adriana Rossi (CERN)

Rossi-2019E-lenscollimation_review_4.pdf

Rossi-2019E-lenscollimation_review_4.pptx

Tuesday, 12 February

08:30 → 10:30 Session 3: Specific design aspects and production status

08:30 Status of LS2 production and prospect for LS3 (20+10)

• Review where we are: status of ongoing production for LS2
• Recap. of experience of LS1 production:
• Plans for future productions: what can we expect for LS3.
• Comments on the prospect for in-kind contributions

Speaker: Inigo Lamas Garcia (CERN)

Status of LS2 production ILG v3.pdf

Status of LS2 production ILG v3.pptx

09:00 Performance of new HL collimator designs (20+10)

• Status of collimator design. New collimators for IR cleaning
• Summary of potential failure scenarios and resulting beam impact on the collimator jaws
• Experience without beam with the prototypes
• HiRadMat : overview and results. What is still missing? Needs for Run III (with LIU beams)
• Status of results from radiation damage tests

Speaker: Alessandro Bertarelli (CERN)

IntnlRev19_HLColDesign_AB.pdf

IntnlRev19_HLColDesign_AB.pptx

09:30 New materials: status (20+10)

• Review of the performance of the MoGr without and with coating
• How can we optimize the production of MoGR?
• Other viable solutions: status of tests and validation [coated Gr or CFC]
• What is missing to validate the CuCD?

Speaker: Federico Carra (CERN)

Materials for the collimator jaws: status and perspectives

10:00 Review of vacuum performance (20+10)

• Review of vacuum tolerances for carbon-based materials
• Proposed coating process for the collimator jaws
• Observed 'problems' with the prototypes and proposed mitigation steps
• IR7 vacuum tolerance in light of the vacuum bump test with beam
• Other coating implementations for the HL-LHC other than on the collimator jaws

Speaker: Giuseppe Bregliozzi (CERN)

FINAL_International Review of the HL-LHC Collimation System _VACUUM_Bregliozzi.pptx

10:30 → 11:00 Coffee break

11:00 → 12:00 Session 3: Specific design aspects and production status

11:00 Collimator controls upgrade plans (20+10)

• Review performance of present system
• Faults driving availability and expectations for HL-LHC
Solutions being studied for controls upgrade, with timeline
• Synergy with consolidation plans

Speaker: Alessandro Masi (CERN)

SMM_CollimatorsControlsUpgradePlans_AM.pptx

11:30 Crystal collimation for lead ion beams (20+10)

• Layouts and beam test results
• Operational experience with high intensities in 2018
• Cleaning performance for ion beam collimation
• Is it an operational alternative for improving ion beam cleaning?
• Outcome of the Crystal Collimation day in Oct. 2018 (hardware options for LS2)

Speaker: Daniele Mirarchi (University of Manchester (GB))

Review_DM.pdf

Review_DM.pptx

12:00 → 13:00 Lunch break

13:00 → 16:00 Executive session (closed session PM)

16:00 → 17:00 Close-out

Collimation_Closeout_2019_all.pdf

Collimation_Closeout_2019_all.pptx