The LARP Collimation Program 13 June 2006 LARP DOE Review - Fermilab Tom Markiewicz/SLAC BNL - FNAL- LBNL - SLAC US LHC Accelerator Research Program

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 2 / 51 LHC Collimation Requirements LHC Beam Parameters for nominal L=1E34cm -2 s -1 : –2808 bunches, 1.15E11 p/bunch, 7 TeV  350 MJ –  t=25ns,  ~200  m (collisions) System Design Requirement: Protect against quenches as beam is lost –Design shielding for expected ~30hr or 3E9 p/s or 3.4kW –Design collimator cooling for  = 1 hour or 8E10 p/s or 90kW –Plan for occasional bursts of  = 12 min or 4E11 p/s or 450kW abort if lasts > 10 sec Collimation system inefficiency: – Inefficiency ∙ Max Loss Rate < Quench Loss Rate –dQ/dV ~ 1.5mW/gm in SC coil causes quench –Estimate inefficiency of collimation system via SIXTRACK program –Determine minimum required inefficiency via FLUKA/MARS 8E6 p/s on TC will quench Q3 in triplet  2E-5 4E11 p/s loss

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 3 / 51 Betatron Collimation in IR7 –3 short (60cm) “Primary” collimators (H,V,S) at 6  –11 long (1m) “Secondary” Collimators (various angles) at 7  Momentum Collimation in IR3 –4 long (1m) “Secondary” collimators Other –1m H&V Copper Tertiary Collimators at Experimental IRs at 8.4  –1m Cu or W Absorbers at 10  –Warm Magnets, tunnel and shielding absorb remainder of lost beam energy Non-Accident Engineering Challenge –The first long secondary collimator downstream of the primary system must absorb much more energy than any other secondary in the system since % of list particles interact inelastically in the 6  primaries –The deformation specification of the collimator jaw is set at 25  m in order to maintain system efficiency The LHC Collimation System Accident Scenario When beam abort system fires asynchronously with respect to abort gap (armed HV trips accidentally) 8 full intensity bunches 1 MJ will impact collimator jaws

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 4 / 51 Phase I and Phase II Collimation Phase I: Use Carbon-Carbon composite as jaw material –60cm/1m Carbon undamaged in Asynchronous Beam Abort –Low energy absorption of secondary debris eases cooling & tolerances 6-7 kW in first 1m C secondary behind of primaries when dE/dt=90 kW –10 sec 450 kW load handled as a transient –Low, but adequate collimation efficiency to protect against quenches at lower L expected at startup –High, but adequate machine impedance for stable operation at low L expected at startup Phase II: Metal collimators into vacant slots behind each Phase I secondary –Good impedance and efficiency allowing LHC to reach design L= 1E34 After stable store open Carbon jaws and close Metal jaws –Jaw will be damaged: what to do? –More energy from primaries will be absorbed: cooling & deformation only pertains to one unlucky collimator per beam!

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 5 / 51 IR7 Collimator Layout 11 Carbon Phase I and 11 Metal Phase II Secondary Collimators per beam in IR Beam Direction Primary Collimators Hard Hit Secondary Collimators

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 6 / 51 Impedance Limits Luminosity Carbon Collimators Dominate Impedance Stable Unstable

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 7 / 51 Copper Similar result was obtained by Ralph A  mann Yunhai Cai Study of Material for Secondary Collimators High Z materials improve system efficiency Copper being considered because its high thermal conductivity Available length for jaws is about 1 meter Achievable efficiency is about 3.5x10 -4 at 10  As Sixtrack program adds absorbers/tertiary collimator we expect ~x10 improvement Carbon

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 8 / 51 Four LARP Collimation Program Tasks: Address Efficiency, Reliability and Design of Phase I & Propose a possible solution for Phase II Use RHIC data to benchmark the code used to predict the cleaning efficiency of the LHC collimation system and develop and test algorithms for setting collimator gaps that can be applied at the LHC Responsible: Angelika Drees, BNL [Task #2] Understand and improve the design of the tertiary collimation system that protects the LHC final focusing magnets and experiments Responsible: Nikolai Mokhov, FNAL [Task #3] Study, design, prototype and test collimators that can be dropped into 32 reserved lattice locations as a part of the “Phase II Collimation Upgrade” required if the LHC is to reach its nominal 1E34 luminosity Responsible: Tom Markiewicz, SLAC [Task #1] Use the facilities and expertise available at BNL and FNAL to irradiate and then measure the properties of the materials that will be used for phase 1 and phase 2 collimator jaws [proposed new work package] Responsable: Nick Simos, BNL [Task #4]

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 9 / 51 Task 2: Use RHIC Data to Benchmark LHC Tracking Codes Scope: –Install SixTrackwColl particle tracking code at BNL and configure it to simulate RHIC performance for both ions and protons. –Take systematic proton and ion data and compare observed beam loss with predictions –Test (and perhaps help to develop) algorithms proposed for the automatic set up of a large number of collimators Resources Required: –50% postdoc/student + supervision + travel Timescale: –Now until LHC beam commissioning Comments –Preliminary data taken; comparison programs being improved –Postdoc search ongoing

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 10 / 51 Task 2: Progress Since June 2005 DOE Review State of affairs June 2005: Ion loss maps in RHIC agree with tracking results, protons do not. Since then, no progress : analysis of proton loss data awaiting manpower –hope is that CERN student who set up Sixtrack with BNL lattice will take BNL postdoc job New work on Collimator efficiency & set up –Heavy Ions and protons very different –positioning procedure for p is slow and tedious and not reproducible –For protons, the effectiveness of the individual collimators changes from store to store and between the IRs Other LARP (not collimation) activities: –LBL luminosity monitor installed in RHIC IR10 between existing luminosity detectors for calibration later this year –E-cloud studies with LHC style electron detectors installed in IR10 Electron Detector in RHIC

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 11 / 51 RHIC Tracking Results Ions Agree With “ICOSIM” Protons Data does not agree

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 12 / 51 Task 3: Model tertiary collimators at the LHC experimental insertions Scope: –CERN FLUKA team occupied with collimation system performance throughout ring and need help understanding beam loss & backgrounds at the EXPERIMENTAL AREAS –MARS team at Fermilab experienced & well equipped Resources Required: –25% postdoc + supervision + travel Timescale: –Now until LHC beam commissioning Status –Initial results promising; More detailed simulations planned Determine Efficiency of TCT and Relative performance of W vs. Cu Engineering Studies, Accident Studies, More realistic Halo, Sensitivity studies –Once 3 more files of input data become available, task can be completed within 6 months and closed down

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 13 / 51 June 2005 Status Modeling tertiary collimators in IP5 and CMS 1m Cu TCTV and z~150m 25mm x 80mm 8.4  10 6 p/s 150m

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 14 / 51 TCT-Induced Energy Deposition in Triplet Quads and Backgrounds entering CMS/ATLAS Peak Energy deposition of 0.35mW/g in Q3 SC coils at  p/s and design spec of  Q<0.53mW/gm  max loss rate at TCT ~ 2 x 10 6 p/s ~ p/s scraped ~ physics backgrounds Photon Flux

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 15 / 51 Example of New MARS15 RESULTS after upgrades to Mars code and updates to layout Outgoing beam: TCTs are pretty radioactive (especially if made of tungsten) and interfere with the TOTEM first station XRP1 at 146 m. Incoming beam: preliminary results for beam-gas are encouraging.

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 16 / 51 Task#1: Phase II Metal Collimators Design a COLLIMATOR with ROTATABLE METAL JAWS –that we can cool to ~<12kW/jaw, keeping T<T FRACTURE and P H2O <~1 atm. –that has reasonable collimation system efficiency & good impedance –that satisfies mechanical space & accuracy requirements –that, when damaged by a (rare) ASYNCH. BEAM ABORT, can still rotate (max. 360°) to present a clean surface to the beam Scope: –Tracking studies to understand efficiency and loss maps of any proposed configuration (SixTrack) –Energy deposition studies to understand heat load under defined “normal” conditions & damage extent in accident (FLUKA) –Engineering studies for cooling & deformation (ANSYS) –Construct 2 prototypes with eventual beam test at LHC in 2008 –After technical choice by CERN, engineering support –Commissioning support after installation by CERN

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 17 / 51 SLAC NLC “Consumable Spoiler” as Prototype for Phase II LHC Secondary Collimator Differences LC / LHC: Jaw length 10cm  100cm Maximum gap & 2mm  4.5cm Power deposited 10W   12 / 60kW/jaw E. Doyle J. Frisch

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 18 / 51 Task Status Summary Trying to Move from Design Mode to Build Mode Original Plan (FY06 Task sheet) FY 2004:Introduction to project FY 2005:Phase II CDR and set up of a collimator lab at SLAC FY 2006:Design, construction & testing of RC1 FY 2007:Design, construction & no-beam testing of RC2 FY 2008:Ship, Install, Beam Tests of RC2 in LHC May-Oct 2008 run FY 2009:Final drawing package for CERN FY 2010:Await production & installation by CERN FY 2011:Commissioning support RC1=Mechanical Prototype; RC2: Beam Test Prototype Deliverables listed 10/6/ Final version of RC1 Conceptual Design Report (CDR) 2.External review of RC1 CDR 3.Thermal tests of single collimator jaw 4.Construct and mechanically test RC1 5.Performance report on RC1 tests

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 19 / 51 FLUKA Energy Deposition Studies Material Study & Input to ANSYS Lew Keller Use CERN-provided hit maps from tracking program to calculate energy deposited in metal Phase II Secondary Collimators at opened to 7 sigma

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 20 / 51 ANSYS 3D Time Dependent Thermal Distortion Studies Material & Water temperature and jaw deflection used to specify –Study materials and material combinations (Copper) –Axial or Helical cooling schemes (Helical) –Jaw support schemes (see detailed discussion later) Design for  beam =1 hour (12kW/jaw for Cu) continuous load with  beam =12 min (60kW/jaw for Cu) transient for 10 seconds beam Eric Doyle 86C  x=394  m Spec: 25  m support Steady State operation

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 21 / 51 Material thermal performance (Hollow Cylinder Model) - O.D = 150 mm, I.D. = 100 mm, L = 1.2 m - NLC-type edge supports

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 22 / 51 Cu chosen as best balance between collimation efficiency, thermal distortion & manufacturability

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 23 / 51 Adapted to LHC Phase II Requirements beam 136mm diameter x 950 mm long jaws (750 mm effective length due to taper). Vacuum tank, jaw support mechanism and support base derived from CERN Phase I.

Helical cooling passages chosen for manufacturability & beamline vacuum safety Per CERN’s Phase I design – no water-vacuum weld or braze EXTERNAL COIL PERMITS 1 REV OF JAW CERN PHASE I JAW POSITIONING MECHANISM – USE IF POSSIBLE Note: baseline case has hollow core

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 25 / 51 Exceeds 200 Max Cu temp Possible boiling Exceeds 42 max water return temp Exceeds Allowed Deflections All temperature simulations based on 20C supply. For CERN 27C supply add 7 to all temperature results. CERN max water return temp 42C Exceeds spec, or other possible problem as noted Baseline Jaw Performance Baseline: hollow Cu, 25mm wall, helical cooling - 5cm pitch

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 26 / 51 IR7 secondary collimators heat generation, deflection and effective length Deflection and effective length based on ANSYS simulations for TCSM.A6L7. Power scaled from TCSM.A6L7 according to the distribution on secondary collimators provided by CERN. Note: first collimator in the series absorbs the bulk of the energy. Steady State Transient

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 27 / 51 Adjustable central aperture-defining stop Stop in/out position controls aperture, actuator external, works through bellows. Leaf springs allow jaw end motion up to 1mm away from beam

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 28 / 51 RF Contact Scheme Blessed by CERN Impedance Police Rigid round-square transition Spring loaded fingers ground two jaws through range of motion Jaw support & gap adjustment borrowed from CERN

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 29 / 51 Agreement with CERN 15-June-2005 Meeting despite Known RC1 Unresolved Engineering Issues Jaw positioning –Design concept for central stop: gap adjust, 5 central position float,.. –Bearings & springs attaching jaws to vertical movers –Load capacity of steppers –Jaw alignment perpendicular to collimation direction Jaw rotation –Specification of mechanism on crowded jaw –Force required to rotate jaws against cooling coil Misc –Spring arrangement for H, V, S orientations –Springs to ensure that device fails open –Damage assessment mechanism (?) –Motors, cables, temperature sensors, position probes, … –Vacuum requirements of 7.5E-10 torr –Interference between RF shield and other components

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 30 / 51 Progress of Phase II Rotating Collimator Project in first half of FY06 RC1 Prototype Conceptual Design Report –reviewed and accepted by CERN and suggestions incorporated rf shielding concept approved –current version Independent review of project and CDR 12/15/05 –Lou Bertolini-LLNL, Alex Makarov-FNAL, Bill Turner (LBL) –Charge: Is the design presented mature enough that the project can proceed to construct the first prototype? –Major Findings: Do not ‘cut metal’ until jaw support, stop and rotation scheme developed –In progress: New ideas result in better performance & simplifications Check thin-Cu over Stainless for performance √ No improvement Increase engineering effort

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 31 / 51 Advances since RC1 Baseline

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 32 / 51 New Idea to Eliminate Central Stop 1.Hub located, in Z, near peak temperature location, which lowers peak temperature, reducing gradient and bending. 2.Both ends of jaw deflect away from beam. 3.Total deflection reduced if the shaft deflection can be minimized 4.Cooling coils embedded in I.D. of outer cylinder.

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 33 / 51 Evolution of jaw-hub-shaft 25mm deep cooling tubes SS 1hr beam Transient beam RC1 – not a practical support scheme More realistic Note reduced shaft end deflection – a positive result if stop is used Next for jaw-hub-shaft: Alternative materials to reduce shaft deflection

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 34 / 51 NLC Jaw Indexing Mechanism Reciprocating linear motion advances jaw by one or more ratchet pitches. LHC system will require opposing ratchet to hold jaw position against cooling tube deformation torque. Mechanism probably will be designed to actuate only when jaw fully retracted.

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 35 / 51 Personnel Issues Full time engineer (Steve Lundgren) and full time designer hired 3 April Several post doc and fixed term candidates interviewed Spending in SLAC shops has begun for thermal tests Active Manpower: Eric Doyle-Engineering (0.25) Lew Keller-FLUKA (0.25) Steve Lundgren-Engineering (1.0) Tom Markiewicz- Integration (0.20) Designer (1.0) Meeting/advice: Tor Raubenheimer Andrei Seryi Joe Frisch Yunhai Cai-Tracking Planned hires: Postdoc#1 Future Effort: Controls Engineer

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 36 / 51 Current Experimental Activities Consistent with Review Committee Dictum to Delay Construction Until Mechanical Design Complete Braze tests of cooling coils in progress: procedures defined Prep for full cooling & deformation tests: parts & lab defined Acquisition of Phase I support & mover assemblies: quote “in the mail” Remodeling of CERN parts for interface to US parts: designer Note faceted face: Vertical Alignment & “Drip Edge”

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 37 / 51 Brazing Tests Cooling Tube Jaw Center Mandrel ~100 mm ~70 mm dia ~100 mm dia

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 38 / 51 Concept to Eliminate 4-Loop Coils at Ends Restrain each tube on centerline of bearing 200mm 136mm dia

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 39 / 51 Reinvigorated Focus on Extent of Damaged Region in the case of the Accident 2000um 500 kW 20 GeV e- beam hitting a 30cm Cu block a few mm from edge for 1.3 sec (0.65 MJ) FNAL Collimator with.5 MJ

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 40 / 51 Cross Section at Shower Maximum Showing Copper Melting and Possible Fracture Regions in a Mis-steering Accident Copper Jaw Melting zone (grey), radius = 3.3 mm Fracture zone, (200 C) radius = 7 mm 2.5 cm ~1MJ Keller, Doyle

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 41 / 51 Inter-Lab Collaboration Good will & cooperation unfortunately limited only by busy work loads –CERN review of SLAC draft CDR –CERN participation in RC1 CDR review –Monthly video meetings –Drawing of support structures for H, V Skew transferred –Many technical exchanges via –Discussions on how to improve communication delays in progress Acquisition of parts will be crucial to delivering prototypes on time –French vendor of collimator jaw assembly has been contacted to negotiate price/delivery for shipment to SLAC: reply immanent –CERN feels that a spare support (Bulgarian company(?)) can be sent without much trouble Plans for damage tests before final delivery date may need to be made Participation in Fall 2006 Phase I testing under discussion

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 42 / 51 Phase II Project at CERN CERN Phase II program is beginning –CERN will concentrate on alternative metal designs A decision on which course to pursue will be taken after operational experience with Phase I system, LHC performance, and beam tests of several prototype designs are considered In all cases, knowledge from SLAC Phase II prototype is deemed valuable input and regardless of final technology choice for Phase II, SLAC will participate in Phase I & Phase II commissioning. Review committee concerned that –Specifications, deliverables, agreements be codified in writing When design complete, will enter into CERN EDMS (eg. Ratti et al) –SLAC will always lose to CERN in a technology down-select Hermann Schmickler promotes effort to a “LARP Hard Deliverable”

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 43 / 51 Phase II Task Summary Project has slipped 6 months in 6 months due to –Reality of hard deliverables as opposed to softer “design” milestones –Staffing delays: failed job offers, safety mandates, personal issues … –Understandable design requests by review committee Nothing we didn’t know about Budget “slipped” 6 months or $430k as well After taking this hit we believe we are on-track to deliver on new schedule –Nervous now about accident condition: begin to discuss beam tests –Believe various steady state requirements are attack-able on an “as good as can be engineered” basis –Excellent recent ideas simplify design and increase performance x5 Expect thermal tests and completely tested RC1 device by end of FY06 and mid-FY07, respectively Need to get full Phase I mechanism from CERN vendor if we are to make RC2 deliver schedule. If SLAC can concentrate on jaws and have rest of infrastructure provided RC2 can meet LHC schedule. –Slippage hopefully consistent with CERN’s newest schedule

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 44 / 51 Task #4: Irradiation Damage Assessment of LHC collimator materials Scope: Irradiate 2-D weave carbon-carbon and exact graphite used in Phase I jaws plus materials considered viable for Phase II jaws BNL AGS/BLIP (70  A of 117 & 200 MeV protons) Measure material properties: thermal expansion, mechanical properties, thermal conductivity/diffusivity and thermal shock BNL “Hot Cell” Sample Measurement Facility Resource Requirements: –BLIP Irradiation charges & hot cell measurement facility use fees –Sample acquisition and preparation –Measurement apparatus improvement –Personnel costs Timescale: –2005,2006 proton runs + analysis into FY2007

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 45 / 51 BNL Irradiation (BLIP) and Post-Irradiation Testing Facilities and Set-Up Layout of multi-material irradiation matrix at BNL BLIP Test Specimen Assembly Remotely- operated tensile testing system in Hot Cell #2 Dilatometer Set-up In Hot Cell #1

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 46 / 51 Task #4 Status Completed: Phase I Carbon-Carbon irradiation Sample activation measurements (mCi, dpa) Thermal Expansion of C-C specimens Preparation of Phase II material samples In Progress: Set up of existing tensile test apparatus & test of irradiated C-C Set up of new thermal conductivity apparatus 2006 Run if Phase II materials in BLIP begun May 4, 2006 Thermal Expansion on Phase II materials that have not been irradiated Specimens highly degraded under dose >> LHC collimator jaws will see.

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 47 / 51 CTE Measurements of Irradiated C-C Strong (fiber plane) direction Irradiation Damage Self Anneals through thermal cycling in both strong and weak directions 7.50 mCi Weak ( ┴ fiber plane) direction

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 48 / 51 Materials for May 2006 BLIP Run are Ready Primary Phase II Materials: Annealed Copper Glidcop (0.15% Al – balance Cu) Other Potential Phase II Materials: Super Invar Gum Metal Other Materials to be (re)tested 2D Carbon-Carbon 3D Carbon-Carbon

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 49 / 51 New Measurement Equipment Thermal Conductivity Measurements Using the Laser Flash Method Laser already in the Hot Lab Experimental Safety Review is taking place at BNL Grad Student from SUNY/SB joined the team Tests are planned for summer and fall FY06

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 50 / 51 Jaw Damage Studies (an increase in scope) Simulations of Extreme Energy Deposition (jaw damage case) Using LS-DYNA Measurements of laser induced ablation of Cu and comparison with LS-DYNA

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 51 / 51 Conclusion The four LARP Collimation program tasks –Provide R&D results to a key LHC subsystem that will need to perform well from the beginning Strong support for all tasks from LHC Collimation group –Play to the unique strengths of the US Labs RHIC as a testbed BNL irradiation test facilities Fermilab’s simulation strength SLAC’s Linear Collider collimator engineering program Concerns –Manpower at BNL for tracking or else nothing will happen –Timeliness of FNAL simulations for input to Phase I design choices –Adequate funds for BNL irradiations studies –Aggressive schedule for a demanding “hard deliverable” prototype Phase II metal collimator Currently far from kind of results you have seen from Instrumentation & Magnet groups

Bonus Slides

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 53 / 51 IR7 Collimator Layout 11 Carbon Phase I and 11 Metal Phase II Secondary Collimators per beam in IR7

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 54 / 51 LHC Beam Dump Abort System R. Schmidt HALO ‘03

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 55 / 51 # Bunches on Collimators  Delay in Retriggering Dump Kicker J.-B. Jeanneret HALO ‘03  t now < ~0.7  s  8 bunches on colls Carbon-Carbon Jaws Chosen for Phase I as they will survive hit by 8 bunches

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 56 / 51 LHC Phase I 25x80mm 2 Carbon/Carbon Secondary Collimators cooled for 7kW DC

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 57 / 51 LHC Phase I 25x80mm 2 Carbon/Carbon Secondary Collimators w/ 7kW cooling Prototypes Made & Tested Full Order Placed

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 58 / 51 Jaw Positioning Forces – Phase I => Phase II Jaw end springs will be sized as com- promise 1) bending-generated force applied to nut 2) static deflection due to jaw weight Pull-in headroom expressed as force at nut Upper jaw - shown Lower jaw Jaw deflection = 400 um for 1 hr beam lifetime case, 1200 um for 10 sec minute lifetime power level

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 59 / 51 Bimetallic jaw (SST/Cu): no benefit Solid Cu beneficial SST/Cu Baseline Hollow Cu Solid Cu No benefit from SST core – same CTE as Cu, poor conductivity – temperature distribution unchanged. Cu core => alt heat path to opposite side, reduces  T therefore bending.

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 60 / 51 Alternative Shaft Materials Shaft supported case - No Major Improvement Deflection is combo of bending & swelling

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 61 / 51 Alternative Shaft Materials Central stop-supported case - No Improvement

LARP DOE Review - 13 June 2006Collimation Tasks - T. MarkiewiczSlide n° 62 / 51 Crystal Collimation Proposal Stages: –Stage 1: feasibility study itself –Stage 2: design of the LHC Phase II Collimation system Goal: deliver a report (of a mini-review?) by next LARP collaboration meeting (~ April 2007), be in position to decide whether to proceed to Stage 2 Plan: –Prepare and perform bent crystal experiments at Tevatron in Fall 2006 –Prepare and perform crystal characterization experiment at SPS H8 line in Sep’06 –Data processing and analysis –Theory work and code development for the LHC