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Critical Review of US-LARP activities on accelerator systems

Critical Review of US-LARP activities on accelerator systems. Based on contributions for/by: IR upgrade studies, beam-beam compensation, e-cloud simulations: Oliver Bruening, Werner Herr, Frank Zimmermann Beam Instrumentation: Rhodri Jones Collimation: Ralph Assmann

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Critical Review of US-LARP activities on accelerator systems

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  1. Critical Review of US-LARP activitieson accelerator systems Based on contributions for/by: • IR upgrade studies, beam-beam compensation, e-cloud simulations: Oliver Bruening, Werner Herr, Frank Zimmermann • Beam Instrumentation: Rhodri Jones • Collimation: Ralph Assmann • Beam Commissioning: Roger Bailey H.Schmickler, LTC 26-9-2006

  2. Outline • 2006 = 1st year of full US-LARP funding • Time for a critical review:- accelerator systems: LTC 27th of September- magnet R&D, hardware commisioning:Special AT meeting on 4th of october feedback to collaboration meeting (end of October, close to BNL) • Information on LHC@FNAL and LAFS • Sensitive issue: Payment of US collaborators (PJAs) • Detailed technical feedback • Conclusions H.Schmickler, LTC 26-9-2006

  3. LHC@FNAL • New bilateral collaboration FNAL – CERN in order to build and operate a CCC copy at FNAL • Initiative by FNAL (Erik Gottschalk et al.) originally motivated for remote operation of LHC experiments • Extended to accelerator control now • Remote Operation and diagnostics has been part of LARP conceptual mandate in the beginning; dropped for low priority. • LHC@FNAL very active; leads to PJAS at CERN; contributing to LHC controls; work supervised by Mike Lamont and Pierre Charrue H.Schmickler, LTC 26-9-2006

  4. LAFS (= LHC Accelerator Fermilab Software?) • Newly proposed bilateral collaboration FNAL-CERN • Collaboration agreement on the desks of the big chiefs • Will make available for controls/operational software efforts up to ten PJAS (a bit optimistic…) • Today focus of work:- Role based access - Sequencing - Snap Shot Analysis Software (Tevatron Operations Tool) • Work defined by Mike Lamont, Eugenia Hatziangeli, Pierre Charrue • Team at FNAL: Dave McGinnis et al. H.Schmickler, LTC 26-9-2006

  5. PJAS at CERN • Very sensitive issue: US –PJAS will come to work at CERN based on several different collaboration agreements- US-LARP, LAFS, LHC@FNAL, others… • In terms of payment they should all be treated the same;i.e. salary by home institute + 4 (5) ksfr/month extra allowance • The collaboration agreements are different:1) LAFS and LHC@FNAL: PJAS allowance paid by CERN2) US-LARP: PJAS funding (mainly for beam commissioning or subsystem commissioning) is part of US-LARP commitment!CERN does NOT pay PJAS allowance3) EXTRA resources demanded by CERN for hardware commissioning: LARP has proposed itself for organization of this help; CERN pays PJAS allowance! • We have to get this clear, otherwise we end up in a big mess. H.Schmickler, LTC 26-9-2006

  6. LHC IR upgrade studies: Feedback on USLARP Collaborations • mainly organized through the CARE / ESGARD HHH network • main deliverable: optics solutions for new IR layout • USLARP is mainly involved in Ni3Sn upgrade studies which are based on the nominal LHC layout  no new optics required • main contribution was the proposal for flat beam operation at LUMI’05 in Archidosso (however, follow-up optics studies were carried out at CERN) • other deliverables: magnetic TAS: • very little progress after 3 years of discussion! • right now all collaborators seem to mainly follow their own agenda • the collaboration could clearly benefit from better coordination! LTC; 27.9.2006 AB-ABP Feedback 6

  7. LHC optics and commissioning studies: Feedback on USLARP Collaborations • mainly organized through direct contacts between CERN & LBNL • main deliverables: • diagnostics tools (procedures) for measuring b-beat in the LHC (% level) • proposal for correction algorithm based on measurements • collaboration works well and first results have been discussed in the LHCCWG at CERN.  collaboration benefits greatly by ‘on site’ residence of a USLARP Toohig fellow  facilitates communication and prepares an eventual active USLARP contribution to the LHC commissioning • Toohig fellow will also participate now in LUMI’06 workshop before the return to BNL LTC; 27.9.2006 AB-ABP Feedback 7

  8. electron cloud studies: Feedback on USLARP Collaborations • mainly organized through direct contacts between CERN & LBNL & BNL • main deliverables: • independent simulation tool to the code that has been developed at CERN  cross check and confidence in simulation results • perform simulation studies for the LHC at LBNL  outsourcing (only 0.2 FTE working on e-cloud at CERN)  USLARP to specify best conditioning scenario during startup • little results in ‘03 / ’04 but bug fixes and new results in ’05 / ‘06  measurements in RHIC and simulations at BNL • provides network for studying e-cloud effects in existing machines • collaboration provides USLARP with insight into effect at LHC and helps during preparing active USLARP support during LHC commissioning LTC; 27.9.2006 AB-ABP Feedback 8

  9. e-cloud heat load in LHC dipole with old & new POSINST w/o re-diffused e- and ECLOUD result (Miguel Furman) OLD POSINST w/o rediffused ECLOUD LTC40 NEW POSINST w/o rediffused note: re-diffused electrons increase heat load ~2x cooling capacity at low & high L

  10. beam-beam studies (simulation and theory): Feedback on USLARP Collaborations • mainly organized through direct contacts between CERN & LBNL • main deliverables: • collaboration on beam-beam simulations with LBL (J. Qiang and M. Furman) on strong-strong simulations on coherent effects and emittance growth.  Same programs are used for RHIC studies. • studies showed potential problem for partially overlapping beams Results have been quantitatively confirmed with other programs. • studies now extended to commissioning and beam finding scenarios, including runs with low luminosity (i.e. 450 GeV)  exchange of results and discussions on regular basis LTC; 27.9.2006 AB-ABP Feedback 10

  11. beam-beam studies (simulation and experiments): Feedback on USLARP Collaborations • mainly organized through direct contacts between CERN & LBNL & FNAL • main deliverables: • experimental and simulation setup for long range beam-beam collision compensation using wires at RHIC in BNL: • compensation of single LR collisionin RHIC MDs in ’05/‘06 • simulation of 60-120 lumped LR collisions in measurement using wires • compensation with two BBLRs for beams colliding head on • explore & demonstrate feasibility of LR compensation for implementation in the LHC. • collaboration works well and first RHIC MD results have been discussed with CERN. However, usefulness of RHIC set-up (only one long range collision point and scalability to LHC is not obvious). LTC; 27.9.2006 AB-ABP Feedback 11

  12. Long-range beam-beam effect in RHIC at 100 GeV • LR at s=10.6m • Octupoles on in Yellow • Blue beam moved measurement of losses vs. separation (Wolfram Fischer)

  13. beam-beam simulation for RHIC experiment (Ji Qiang): emittance growth vs. tunes for different separations 5s separation 4s separation 6s separation

  14. US-LARP Instrumentation PackagesInstrumenting the TAN – Luminosity monitors for IR1 and IR5 • Started with LBNL as part of the US-LHC construction project • Initial R&D very promising • Problems with US-LARP budget approval slowed things down considerably a few years ago, along with a lack of CERN manpower for effective follow-up. • Due to this, CERN limits collaboration with LBNL to luminosity and longitudinal profile monitoring is abandoned • Recent injection of new manpower by LBNL and a pressing installation schedule have served to advance the project significantly • It does now look as if the deliverables will be installed just in time

  15. US-LARP Instrumentation PackagesTune, Coupling and Chromaticity Feedback – BNL & FNAL • Started as bilateral agreement between CERN & BNL – later integrated into LARP with additional support from FNAL • Original deliverable was for complete PLL tune system • Was never really viable for such a critical LHC system • New system (BBQ) is CERN designed and built, but based on the lessons learned from the RHIC system • Testing of this system at both RHIC and Tevatron has been invaluable in the continued development of the system. • Understanding the effect of coupling on the PLL and its subsequent measurement at RHIC was a major leap forward. • RHIC has now successfully tested both tune and coupling feedback using a CERN BBQ front-end • Both parties currently working on demonstrating chromaticity feedback • This has been a very positive collaboration which will hopefully ensure that the LHC starts up with a viable PLL tune meter capable of being used for tune, chromaticity and coupling feedback.

  16. Accepted as part of LARP in October 2006 A strong driving force both on the CERN side (Fritz Caspers) and FNAL side (Ralph Pasquinelli) has ensured that 4 Schottky monitors are now being assembled for installation at CERN next month This has been a model collaboration with both sides open to new ideas while working towards a common goal. Time was invariably helped by the very tight time constraints imposed on the project! General Remarks on all US-LARP instrumentation packages Role of beam commissioners needs to be clarified between labs & LARP Who can come, for how long and when Support is required for the software integration of these systems Who does what still to be clarified between LHC@FNAL / BI / CO US-LARP Instrumentation PackagesLHC Schottky monitoring – FNAL

  17. Status of LARP Activities on Collimation SLAC – Phase 2 collimator for LHC beam tests: Work proceeding well. Dedicated SLAC work force increased. Cutting metal at SLAC. FNAL – Study tertiary collimators (TCT) IR1/IR5: After initial delays and complaints recently results presented for IR5. Confirms TCT design choices gain factor 5-10. Completed once IR1 is done. BNL – Radiation tests for collimator materials: Important experimental radiation data for CFC material. Good news on radiation resistance though damage concern remains. BNL – Comparison RHIC loss maps with predictions: Very limited progress. CERN doctoral student (G. Robert-Demolaize) will join BNL/RHIC on January 1st. Continue work… http://www-project.slac.stanford.edu/ilc/larp/ Work driven through monthly video meetings BNL – CERN – FNAL – SLAC! Talks and info on web site (see above). US coordination: T. Markiewicz, SLAC

  18. SLAC Collimator Design and Prototyping: Rotatable LHC Collimator Strong SLAC commitment and effort: Theoretical studies, mechanical design, prototyping. New full time mechanical engineer hired. Looking for SLAC post-doc on LHC collimation! Design with 2 rotatable Cu jaws First prototype with helical cooling circuit (SLAC workshop)

  19. Collimator Infrastructure @ SLAC in Construction The “clean tent” Next steps @ SLAC: Assembly of prototype jaw. Heating (20 kW) and cooling test. Deformation tests. Cooling Heating and power Instrumentation Support table

  20. FNAL: IR1/5 Radiation from Beam Halo with TCT’s Peak power density in Q3 SC coils: 6.e-5 mW/g Peak absorbed dose: a few kGy/yr Peak residual dose: 7 mSv/hr Many more results (heating in SC triplet magnets, radiation, IR5 background): http://www-project.slac.stanford.edu/ilc/talks/larp/2006-08-23/mokhov-tct-aug06.ppt  IR1 to be done to complete job. Use CERN/FLUKA set-up for LHC operation!?

  21. Serious DAMAGE of 2D CFC after heavy irradiation exposure BNL: Radiation Tests on Collimator Materials • 1020 p shot on CFC collimator material (phase 1): • Good radiation resistance! • Damage! • Dose much higher than yearly dose on most exposed LHC collimators (~1016 p/year). • Work to extrapolate to LHC losses (FLUKA team). • Further work ongoing/planned for phase 2 materials.

  22. View from the CERN Side LARP collimation activities focus internationally available expertise on LHC collimation, are useful for CERN and are productive: SLAC: Phase 2 prototype collimator for LHC beam tests in 2008 or 2009! SLAC is working very persistently and is dedicated (hiring of additional staff). Cutting metal at SLAC… FNAL: Beam loss and radiation studies in IR1 and IR5 give important insights for study of tertiary collimators and background. After some delays and complaints very good results are now presented. Important reference data for LHC operation. BNL: Tests of material make use of a unique radiation facility for test and analysis at BNL. Important reference data for LHC operation and for improving with phase 2 materials. BNL: Beam loss maps for RHIC have been recorded. Limited progress in analysis and comparison with simulation. Work reinforced as a core member of the CERN collimation team joins BNL/RHIC after completion of his PhD. Issues: Agree to complete and finish FNAL studies after results are available? Requires to put CERN resources for setting up IR1 and IR5 FLUKA models. Gain in terms of fast reaction time to possibly critical IR issues!

  23. LTC Sep 27th 06 : LHC commissioning organisation

  24. Take As Given Develop These

  25. US LARP involvement • No involvement in core team working 24/7 in the CCC • Interest expressed in many Accelerator Systems • Mostly • AP, BI (see slides) • Controls (not LARP, but rather LHC@FNAL) • Collimators • And a little on • Beam transfer • Snapback, ramp, squeeze • Machine protection • So nearly all covered by other LARP chapters • Our present scheme does not explicitly have a pool of experienced people for general troubleshooting • Perhaps this is something that we need • If so this is a role where the right USstaff could contribute

  26. Summary (1/3) • Administartion problem of PJAS payment to be communicated (again) and to be respected in all branches of the collaboration. • New initiatives (LHC@FNAL, LAFS) popping up. These are well matched to the immediate needs of the LHC. New US-LARP collaboration proposals as discussed during / after the collaboration meeting of April 2006(LTC) found by far less enthusiastic CERN reactions.For US-LARP to rethink its strategy… • US-LARP is receptive for criticism and the proposal of corrective measures: example: collimation simulation studies at FNAL, engineering approach for luminosity monitors at LBL…

  27. Summary (2/3) • LHC IR upgrade studies: Better Coordination required • E-Cloud simulations: Positive results, Should be maintained at that low level of effort • B-B compensation: Completely unclear if work in the US at RHIC is relevant for LHC: Should be worked out in a review • B-B simulations: Good results • LHC lumi monitors: Reduced Scope (IP1 and IP5 only), good progress to deliver in time. • Tune and Chromaticity feedback: Good results, technology driven by CERN, active collaboration • Schottky Monitors: Good progress due to strong engagement on CERN and FNAL side.

  28. Summary (3/3) • In general all BI: Software design, coding and testing not defined. Needs to be done now in collaboration with AB-CO and AB-OP. • 4 different labs involved in collimation activity…working pretty well. • Beam Commissioning: Long iterations for the past 2 years. Present US-LARP involvement/commitment only on present collaboration items.From CERN the future LHC operations teams are well defined and slots/roles are made available for outside collaborators. US-LARP has to manifest further interest now.

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