LARP Accelerator Systems D. Rice, J. Rosenzweig, M. White LARP 2009 review

General topics Quality and relevance of work Spin-off strategy Beam dynamics coordinating activities Funding

Quality and Relevance of Work Findings: – Overall very high quality – Undoubtedly contributing to LHC luminosity goals – Coordination with CERN gives generally relevant results, with intermittent problems

Quality and Relevance of Work Comments: – Direction is impressive for some projects, others can be improved – CERN seems not able to give clear direction during commissioning period

Quality and Relevance of Work Recommendations – Exploit LARP-installed hardware for full physics potential, and to close design loop Student, Fellow involvement important – Develop independent analysis of luminosity upgrade optimization path, and place LARP activities within this path Keep alert on energy dependence Emphasize US/LARP strengths Provide proactive guidance to CERN

Spin-off strategy Findings – Transitions from R&D to project are inherent to LARP activities One of the best features of LARP – Examples: Lumi, Roman pots… crab cavity, PS2

Spin-off strategy Comments – Transitions from R&D to project present particular challenges to LARP – Must manage these valued spinoff activities well

Spin-off strategy Recommendations – Internal criteria for deciding when to transition should be developed Cost threshold Rigorous schedule needed Deliverables identified

Beam dynamics coordination Findings – Many LARP activities are centered on beam dynamics: Space-charge, e-lens, e-cloud, collimations, crab crossing, etc. – The magnet effort in LARP is impacted by beam dynamics considerations

Beam dynamics coordination Comments – An independent LARP effort in LHC beam dynamics would be valuable to both LARP and CERN – The magnet effort in LARP should be informed by beam dynamics expertise inside the collaboration

Beam dynamics coordination Recommendations – Develop an independent LARP effort in LHC beam dynamics, with student/Toohig Fellow emphasis – Make use of beam dynamics calculations to guide magnet development efforts

Funding Findings – Out year funding appears to decline in planning – No precise activities in accelerator physics appear after 2012

Funding Comments – Does not appear to ensure return on investment – Gives DoE a misleading indication of need for future high impact LHC research Many research thrusts are identified and examined each year One believes that at least a constant level of activity is likely – LHC commissioning will indicate specific paths Do not squander opportunity to participate

Funding Recommendation – Do not be shy about funding requests LARP has shown its worth – Put place-holder in lieu of specific projects in far- future funding plans

Lumi-Schottky Findings – Success in installation – Initial performance promising – Final performance TBD after restart

Lumi-Schottky Comments – Complete remaining effort on Lumi hardware – Should follow through on these experimental development efforts – Lower energy operation of LHC may present challenges in employing monitors – Hihger intensity after upgrade may require new lumi monitor design, based on simulation and coordination with new IP layouts

Lumi-Schottky Recommendations – Ensure maximum impact from LARP through experimental program based on these hardware development successes – Engage students, Fellows in work – Examine lumi upgrade paths based on LHC upgrade plans

Collimators Findings – Rotable collimator development progressing – Development schedule has uncertainties Tied to CERN facility availability – Deployment uncertain due to inhouse CERN competing designs

Collimators Comments – Future possibilities with CERN must be clarified

Collimators Recommendations – After finishing RC1, evaluate direction of program jointly with CERN – Make sure resources demanded are likely to yield project with reasonable chance of implementation

PS2 Findings – Potential high impact on LHC luminosity – Enthusiastic support from CERN – Initial efforts well organized – Clear work plan, exploiting US lab strengths Modeling of space charge, e-cloud, instabilities, feedback

PS2 Comments – This activity poised to reach project level quickly Even only with modeling effort leading to CDR – Hardware design implications in/after CDR

PS2 Recommendations – CDR writing should be considered a deliverable – Continue to work with CERN toquickly converge on scope of US effort – Clarify schedule

E-cloud Findings – Popular, intricate subject – Excellent work in LARP – Reasonable agreement between SPS measurements and simulation found – Impedance model under development, with goal of understanding feedback – Feedback hardware studied

E-cloud Comments – Possible high impact on LHC luminosity – Impedance/feedback effort is ambitious But necessary… other mitigation not feasible in existing machine – Nonlinear interaction may elude accurate linear description – End goal of activity of e-cloud activities not yet well defined

E-cloud Recommendations – Proceed to next level of experiments Driven beam – Define project goals as quickly as possible Will guide specific activities in this critical area

E-lens Findings – Simulations indicate luminosity gains possible – Head-on beam-beam compensation not high CERN priority – Long range BB mitigated with wire technique – Much expertise and development work in US on e-lens FNAL BNL (RHIC, complementary, ongoing) – New concept of hollow e-lens proposed

E-lens Comments – Should be driven by CERN, favors e-coli effort

E-lens Recommendations – Leverage off of RHIC development, and installed FNAL infrastructure – Concentrate on hollow-beam R&D

Crab cavity Findings – Potential high impact under upgrade scenarios with lower beta* – KEKB experience encouraging – Technology exists for cavities – Large collaboration

Crab cavity Comments – Very expensive project, large scope – Will need to react to pending collaboration decision on implementation – Continued progress will require much augmented effort and funding soon – Verify effects on detectors negligible

Crab cavity Recommendations – Should project go forward, support in base program