July 7, 2008SLAC Annual Program ReviewPage 1/23 LHC Accelerator Research at SLAC T. Markiewicz SLAC Department Head (9/2008) LARP Accelerator Systems Division Leader (9/2008) LARP Collimation Leader (9/2005) LARP Rotatable Collimator Manager (9/2004)

July 7, 2008SLAC Annual Program ReviewPage 2/23 LARP LHC Accelerator Research Program Mission Statement: –Make more LHC luminosity earlier –Use, develop and preserve unique US resources and capabilities in accelerator science and technology BNL - FNAL- LBNL - SLAC Accelerator Systems –Instrumentation –Collimation –Accelerator Physics Nb 3 Sn Magnet Systems Program Management –Beam and Hardware Commissioning –Long Term Visitors to CERN –Toohig Fellowships

July 7, 2008SLAC Annual Program ReviewPage 3/23 History of SLAC as member of LARP FY 2003Jim Strait talk at “SLAC Futures” series mentions challenges in LHC collimation. Discussions with CERN & LARP lead to invitation to join LARP to adapt NLC “rotatable collimator” to LHC LARP Funding FY 2004Introduction to LHC collimation project; Begin design studies: FLUKA, ANSYS, SixTrack 110k$ FY 2005Continue studies, agree on performance specs with CERN, write Conceptual Design Report of a Phase II collimator 190k$ FY 2006 Design Review; hire ME & CAD; re-design and begin to fab small prototypes & set up test lab 350k$ FY 2007Collimator Engineering (hire postdoc) Beam-Beam simulation effort in ACD begins Chao-Phinney-Wienands coordinate beam commissioning requests Program Management + LARP travel 800k$+ 30k$+ 18k$+ 50k$= 898k$ FY 2008Collimator Engineering Beam-Beam simulation effort in ACD for Electron Lens & Wires Beam Commissioning travel for LLRF, SPS e-cloud, Beam Inst. New Initiatives: CRYSTAL Collimation & Crab Cavity Program Management + LARP travel 950k$+ 80k$+ 40k$+ 95k$+ 240k$= 1405k$

July 7, 2008SLAC Annual Program ReviewPage 4/23 LHC AR at SLAC begins FY 2008 LHC AR at SLAC Advisory Committee *Alex Chao *TWM *Nan Phinney *Tor Raubenheimer *Uli Wienands

July 7, 2008SLAC Annual Program ReviewPage 5/23 LHC Accelerator Research at SLAC Department Concept Participate in the LHC accelerator physics program: –by contributing in areas where SLAC has expertise & experience –enhance SLAC’s areas of core excellence: collective effects, RF cavity design, collimation systems,… –educate SLAC staff on HEP’s only energy frontier machine –develop contact with next generation of accelerator physicists Use US LARP to coordinate & validate R&D plans and performance –NOT independent bi-lateral SLAC/CERN planning Use US LARP funding when possible, especially to leverage SLAC labor through M&S & Travel Use SLAC ARD funds as available for programs LARP cannot fund –ARD plan calls for ~8 FTEs for last half of FY08

July 7, 2008SLAC Annual Program ReviewPage 6/23 LHC-AR Tasks & People Funded by LARP in FY08 Rotatable CollimatorsGene Anzalone (MFD) Eric Doyle (LHC-AR) Lew Keller (ret.) Steve Lundgren (LHC-AR) Tom Markiewicz (LHC-AR) Jeff Smith (LHC-AR) Simulation of beam-beam effects in support of Wire & Electron Lens compensation schemes A. Kabel (ACD)

July 7, 2008SLAC Annual Program ReviewPage 7/23 SLAC #PeopleProject LHC LLRFJohn Fox, Claudio Rivetta, Themis Mastorides, Dan van Winkle Adapt PEP-II LLRF Tools to LHC & Use for System Configuration, Study & Improvement SPS RF Feedback to control Ecloud John Fox, Jiajing XuStudies of Transverse RF to control Electron Cloud Instabilities in the SPS SPS Vacuum Ch to control Ecloud Mauro Pivi, Lanfa WangEcloud Remediation via Grooved & Coated Vacuum Chambers LHC Beam Commissioning Alan FisherLHC Instrumentation Commissioning LHC Crab CavityAndrei Seryi, Cho Ng, Zenghai Li, Liling Xiao Crab Cavity Studies Crystal CollimationAndrei Seryi, Tom Markiewicz, Shilun Pei, Jeff Smith, Gennady Stupakov, Bob Noble Crystal Collimation experiments at SPS and Tevatron with extension to e-,e+ tests at SLAC PS2 StudiesUli WienandsDevelop US Plan to participate in CERN White Paper for PS2 design LHC AR Tasks Proposed to LARP in FY08 & Accepted in LARP FY09 Plan FY08 Travel Funded by LARP FY08 Labor Funded by SLAC LARP budget allocation in FY09 still TBD!!

July 7, 2008SLAC Annual Program ReviewPage 8/23 SLAC Concept for LHC Phase II Secondary Collimators Improve LHC Impedance and Collimation Efficiency beam beam spacing: geometrical constraint Length available 1.47 m flange - flange Jaw translation mechanism and collimator support base: LHC Phase I 12 kW per jaw Steady State heat dissipation Cu coolant supply tubes twist to allow jaw rotation Hub area Glidcop Cu Mo Cantilever Mo both ends Helical cooling channels 25mm below surface 20 facets

July 7, 2008SLAC Annual Program ReviewPage 9/23 Cu Jaw-Cu Hub-Mo Shaft Design 2mm shaft-jaw gap gives x5 improvement in thermal deformation over solid shaft-jaw design 1260 um  236 um (60kW/jaw,  12min) 426 um  84 um (12kW/jaw,  =60min) Rather than Cu, Moly shaft improves Gravity sag x3: 200 um  67 um Thermal bulge 30%: 339 um  236 um

July 7, 2008SLAC Annual Program ReviewPage 10/23 Status of RC Program 1.Jaw support & rotation mechanism COMPLETE (June 2007) 2.First full single jaw-hub-shaft unit COMPLETE 3.Preliminary tests indicate performance in accord with FEA to ~10% Final Jaw Braze 22 April 2008 Test Stand with External Heaters

July 7, 2008SLAC Annual Program ReviewPage 11/23 RC Program Plans FY2008-FY2009 Plan: Complete RC1: Finalize RF design Test a few new concepts to simplify machining & brazing process Order parts for 2-3 new jaws: copper mandrels, Mo shafts, Glidcop® jaws Fab & braze 2-jaws, 4-supports, RF features in new vacuum tank Metrology & vacuum tests Mechanical motion tests on existing CERN system Ship to CERN in late 2009 for SPS Transfer Line Robustness Test LHC Beam Dynamics Test FY2010 and beyond If production decision made, provide engineering & commissioning support

July 7, 2008SLAC Annual Program ReviewPage 12/23 Beam-Beam Simulations Andreas Kabel (ACD) Goal –Benchmark beam-beam simulations codes with RHIC experimental data and evaluate the LHC beam-beam performance with long-range and head-on beam-beam compensation PLIBB code –PIC code, with MAD-X lattice input & Intra-beam scattering –for RHIC wire experiments and Electron lens Example: Beam Transfer Function for RHIC wire compensator vs. simulation

July 7, 2008SLAC Annual Program ReviewPage 13/23 LHC LLRF John Fox, Claudio Rivetta, Themis Mastorides, Dan van Winkle Why SLAC? –PEP-II and LHC have same basic LLRF architecture –SLAC Group has much unique expertise and well developed set of software tools developed for PEP-II that can be used to configure the LHC system, study it and improve it Progress in 2008 –Three multi-weeks trips in April, June 2008 –SLAC software model configured for LHC and interfaced to control system Near Term Plans –4 more person-weeks at CERN in FY08 for beam commissioning Data from closed loop LLRF system with beam present will be compared against model and changes to LHC hardware configuration suggested –Expand model to include feedback & longitudinal emittance dilution –Eventually, develop theory & programs to model the long-term (24 hr) behavior

July 7, 2008SLAC Annual Program ReviewPage 14/23 Sample LLRF Result Open Loop Xfer Function from time- domain excitation technique vs. model result (green)

July 7, 2008SLAC Annual Program ReviewPage 15/23 Transverse RF Feedback in SPS to Control Beam Instabilities Produced by Electron Cloud Effects John Fox, Jiajing Xu with LBL&CERN SPS Ecloud dynamics studies predict –Horizontal - coupled-bunch behavior –Vertical - single bunch-like instability 2008 Plan –Measure & quantify Ecloud effects on beam (instrumentation) –Compare measurements with E cloud/beam models ≥2009 Plan –Develop beam-FB simulation, evaluate possible feedback implementations. –Propose a technical implementation & develop Engineering Specs –Proof of principle experiments & technical R&D Eventual possible LHC construction project item

July 7, 2008SLAC Annual Program ReviewPage 16/23 Transverse RF Feedback Measurements & HW Measurements of x-y bunch structure in SPS will be made in August. Initial measurements taken parasitically in June show a high frequency structure on the beam, but have instrumental issues Example of existing bunch-by-bunch FB (PEP-II, KEKB,..) SPS and LHC needs may drive new processing schemes and architectures

July 7, 2008SLAC Annual Program ReviewPage 17/23 Experimentation to Investigate Possible Use of Crystals as High Efficiency Primary Collimators Andrei Seryi, Tom Markiewicz, Bob Noble, Shilun Pei, Jeff Smith, Gennady Stupakov Why SLAC: –Traditional expertise in collimation optics & devices for accelerators with high power density beams Where: –T980 at FNAL Tevatron - now through 2010(?) –CRYSTAL at the SPS – now through 2009 –Possible future e+/e- experiments at SLAC NLCTA and FACET Collaborators RD22 team from CERN-Italy-Russia ( SPS & H8 extracted line) Fermilab team ( , Tevatron) BNL Team (2005 RHIC) Status & Plans Engineering plan for contributing “Roman Pot” Data analysis & interpretation Application to electrons and possible production of photon beams

July 7, 2008SLAC Annual Program ReviewPage 18/23

July 7, 2008SLAC Annual Program ReviewPage 19/23 Grooved Vacuum Insertion Test at the SPS for Electron Cloud Studies Mauro Pivi, Lanfa Wang with LBL&CERN Electron cloud mitigation test chambers for SPS in prep –SLAC is manufacturing two grooved insertions Metal folding & razor blades techniques for 1mm max. height –Installation Testing planned in summer 2008 Metal Folding: Form multiple folds. [EMEGA Company, USA]Brazed-up Assembly: Use individual razor type foil blades

July 7, 2008SLAC Annual Program ReviewPage 20/23 LHC Crab Cavity Andrei Seryi, Cho Ng, Zenghai Li, Liling Xiao Crab Cavities for each beam and each IP are needed for any luminosity upgrade requiring a larger crossing angle SLAC ILC Crab Cavity design experience and ACD computational tools immediately applicable Crab Cavity collaboration of all LARP labs, CERN and others (KEK, RAL, JLAB,…) SLAC responsibilities in areas of: –RF modeling of cavity & coupler design –HOM damping & Multipacting Studies –Thermal & Mechanical studies with TEM3P code and and ANSYS cross-check: –Crab and collimation –Overall coordination

July 7, 2008SLAC Annual Program ReviewPage 21/23

July 7, 2008SLAC Annual Program ReviewPage 22/23 CERN PS2 (replacement for PS) studies Uli Wienands et al *Scope and budget are under discussion *Synergies with the FNAL MI upgrade *Interest from all 4 LARP labs 3 possible packages 1.Intensity effects, instabilities 2.RF system 3.Tracking, nonlinearities, space charge, halos, H- injection LARP+LAUC DOE Review – June 2008LARP Accelerator Physics - W. FischerSlide n° 22

July 7, 2008SLAC Annual Program ReviewPage 23/23 Summary SLAC initially got involved with LHC accelerator research through LARP as a by-product of its Linear Collider collimator R&D SLAC expertise and experience is highly relevant in many other areas and effort is sought after by LARP and by CERN These expanded activities are just beginning, with good early results, supported both by LARP and by SLAC SLAC is prepared to participate in a US “LHC Luminosity Upgrade Project” & is participating in ongoing scope and schedule discussions