1. The LARP Collimation Program 05 June 2007 LARP DOE Review - Fermilab Tom Markiewicz/SLAC BNL - FNAL- LBNL - SLAC US LHC Accelerator Research Program

2. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 2 / 55 Four LARP Collimation Program Tasks: Address Efficiency, Reliability and Design of Phase I & Prototype 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 ENDS FY07 Understand and improve the design of the tertiary collimation system that protects the LHC final focusing magnets and experiments Responsible: Nikolai Mokhov, FNAL  TASK ENDS FY07 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 Use the facilities and expertise available at BNL to irradiate and then measure the properties of the materials that will be used for phase 1 and phase 2 collimator jaws Responsible: Nick Simos, BNL  TASK ENDS FY07

3. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 3 / 55 Task: 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 Status: Guillaume Robert-Demolaize (ex-CERN) hired January 2007 BNL up and runningThe tracking tools developed at CERN are now up and running for RHIC proton beam simulations. Even though the tracking code itself is portable and can be used for any machine, the aperture model is specific to each machine studied => had to generate one for the RHIC lattice ! fully compatibleWhile still in its early stages, it is already fully compatible with the established tools; some effort is still dedicated in refining it (transition regions, local aperture restrictions…). enough data for the first preliminary studiesThe events selected so far contained enough data for the first preliminary studies that allowed for debugging of the new functions of the codes

4. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 4 / 55 Task 2: Progress Since June 2005 DOE Review Simulating a horizontal jaw movement (1) (2) (1) (2) Effect on BLM signal

5. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 5 / 55 Task: Model tertiary collimators at the LHC experimental insertions Study of betatron collimation and beam-gas debris cleanup by tertiary collimators in IP1 & IP5 complete –Peak energy deposition in IRQ is more than two orders of magnitude below the quench limits at normal operation and nominal parameters. Tungsten is noticeably better than copper (1 meter). Betatron cleaning contribution dominates over beam-gas, esp. for 0.22- hr beam life time. –Tertiary collimators noticeably reduce machine backgrounds at small radii (pixels, tracker) and protect these components at beam accidents. Backgrounds and radiation levels in the CMS and ATLAS detectors are dominated – at nominal luminosity - by pp-collisions. Tungsten is better. There is only a minor effect of TCTs at radii > 1 m..Momentum cleaning and an impact of a single bunch loss on TCT still need to be addressed (need someone to help!).

6. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 6 / 55 Neutron (bgas & pp) and Muon Fluxes (bgas) in CMS With tertiary collimators in

7. LARP Rotatable Collimators for LHC Phase II Collimation Representing Gene Anzalone, Eric Doyle, Lew Keller & Steve Lundgren BNL - FNAL- LBNL - SLAC US LHC Accelerator Research Program

8. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 8 / 55 CERN Collimation Plan & Schedule 0) Assume SLAC LARP develops Rotatable Collimator 1) Develop TWO other complementary designs 2) Develop a test stand for the three designs 3) Fabricate 30 Phase II collimators of chosen design & 6 spares The target schedule for phase 2 of LHC collimation: 2005Start of phase 2 collimator R&D at SLAC (LARP) with CERN support. 2006/7Start of phase 2 collimator R&D at CERN. 2009Completion of three full phase 2 collimator prototypes at CERN and SLAC. Prototype qualification in a 450 GeV beam test stand at CERN. 2010Installation of prototypes into the LHC and tests with LHC beam at 7 TeV. Decision on phase 2 design and production at end of year 2011Production of 36 phase 2 collimators. 2012Installation of 30 phase 2 collimators during the 2010/11 shutdown. Commissioning of the phase 2 collimation system. LHC ready for nominal and higher intensities. REDOne year slip from recent white paper, “Second Phase LHC Collimators”

9. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 9 / 55 June 2006 DOE Review Introduce new jaw-hub-shaft design which eliminates central stop & flexible springs x5 improvement in thermal deformation 1260 um  236 um (60kW/jaw,  12min) 426 um  84 um (12kW/jaw, t=60min)

10. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 10 / 55 Restrain each tube on centerline of bearing 960mm 136mm dia June 2006 DOE Review Introduce new reverse-bend winding concept for the cooling coil which eliminates the 3 end loops, permitting longer jaws and freeing up valuable space for jaw supports, rotation mechanism and RF-features EXTERNAL COIL PERMITS 1 REV OF JAW Sheet Metal formed RF transition 4-1/2 Turns without failure

11. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 11 / 55 Main accomplishments in the last year Hundreds of 3-D concept & 2-D manufacturing drawings made Rotation & support mechanism fully designed and manufactured Many test pieces manufactured and examined, tooling developed, and, especially, brazing protocols worked out All parts for first full length jaw assembly manufactured & in-house Test lab fully wired, plumbed and equipped

12. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 12 / 55 Model showing 42.5 winds of coil on Mandrel with 80mm wide space for U-Bend at downstream end

13. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 13 / 55 Comparison of Hollow Moly shaft and Solid Copper Shaft to same FLUKA secondaries: Improved deflections Solid Cu, 75cm tapered jaw, asymmetric hub Tubular Moly, 95 cm straight jaw, symmetric hub Steady State  =1 hour  = 12 min for 10 sec Steady State  =1 hour  = 12 min for 10 sec Gravity sag200 um67.5 um Power absorbed11.7 kW58.5 kW12.9 kW64.5 kW Peak Temp.66.3 °C197 °C66 °C198 °C Midjaw  x 100 um339 um83.6 um236 um Effective Length51 cm25 cm74 cm39 cm Sagitta221 um881 um197 um781 um

14. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 14 / 55 Current Upstream end with actuator and cooling lines

15. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 15 / 55 Introduce new Internally actuated drive for rotating after beam abort damages surface New rotation drive with “Geneva Mechanism” NLC Jaw Ratchet Mechanism Universal Joint Drive Axle Assembly Thermal expansion Gravity sag Differential transverse displacement

16. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 16 / 55 Upstream end vertical section Jaw Geneva Mechanism Support Bearings Worm Gear Shaft Water Cooling Channel U-Joint Axle Lundgren 1-2mm Gap Diaphragm

17. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 17 / 55 RF Shielding: ONLY PART THAT REMAINS TO BE DESIGNED Baseline Concept Tie-Rods with Fingers Connect Jaws & Tank Issues: –At a few 10s of grams per finger (.1 mΩ/contact) force causes excessive deflection of the tie-rod holding fingers –Cooling required Discussions with CERN and PeP-II experts in progress Tie-Rods

18. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 18 / 55 Revised RF Spring configuration under consideration Double Wedge Adapters mount across Tank ceiling & floor 2 RF springs mount to each Adapter Jaw facet RF springs mount on Tank ceiling & floor Shorter length springs also mount to Tank ceiling & floor Note: Jaw facet springs are wide enough for line contact thru full transverse travel range

19. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 19 / 55 RF Contact Springs for Investigation

20. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 20 / 55 BrazeTest #1 (shown June 2006) Cooling Tube Jaw Center Mandrel ~100 mm ~70 mm dia ~100 mm dia

21. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 21 / 55 Aluminum Mandrel for Coil Winding Test and to test 3-axis CNC Mill before cutting 200mm and 950mm Copper Mandrels 200mm Cooling Tube aligner

22. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 22 / 55 Development of Winding Tooling Vise-Type Roller-Type Aluminum Mandrel with Coil Wound Test Winding the 200mm Copper Mandrel

23. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 23 / 55 Fabrication of Quarter Jaws for 2 nd Braze Test

24. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 24 / 55 Final Wind of 200mm Copper Mandrel

25. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 25 / 55 First 200mm Prototype Before-After Brazing Coil to Mandrel 4 braze cycles were required before part deemed good enough to do jaw braze Learned a lot about required tolerances of cooling coil and mandrel grooves Pre-Coil-Braze

26. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 26 / 55 More Winding Tooling Developed 1m winding tooling Mill vise as precision bender

27. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 27 / 55 1mm raised shoulder (Hub) at center Full Length Molybdenum Shaft

28. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 28 / 55 Braze Test#2 Delivered 19 Dec 2006

29. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 29 / 55 Vacuum Bake Test Results: 4/1/07 ~3x over LHC Spec 1st Jaw Braze Test Assembly has been vacuum baked at 300 degrees C for 32 hours. LHC Requirement = 1E-7 Pa = 7.5E-10 Torr Baseline pressure of Vacuum Test Chamber: 4.3E-7 Pa (3.2E-9 Torr) Pressure w/ 200mm Jaw Assy. in Test Chamber: 4.9E-7 Pa (3.7E-9 Torr) Presumed pressure of 200mm lg. Jaw Assy.: 6.0E-8 Pa (4.5E-10 Torr) Note: above readings were from gauges in the foreline, closer to the pump than to the Test Chamber. Pressures at the part could be higher. SLAC vacuum group has suggested longitudinal grooves be incorporated into the inner length of jaws; incorporated into next prototype Next steps: Use in Moly-Hub cold press fit Sectioning & examine braze quality

30. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 30 / 55 Aluminum Test Mandrel with 80mm Gap for Downstream U-Bend (11/17/06)

31. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 31 / 55 Braze Test #3: 200mm Cu mandrel with U-Bend Upstream end of mandrel Tubing Wound and Tack Welded to Mandrel at the U-Bend Note stub ends of cooling tube

32. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 32 / 55 Braze Test #3: Coil-mandrel brazed & 8 ¼-round jaws prepped Next steps: -Braze jaws by mid-June NB: experience is indicating 20cm long full round jaws may be feasible -Vacuum test? -Section & examine braze quality After 2 braze cycles, OD & braze wire grooves machined

33. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 33 / 55 Fear of Copper-Moly Braze Joint Leads to Mini Devoted R&D Cycle #1 - Mandrel Dummy #2 - Mo Shaft Dummy #3 - Mo Backing Ring #4 - Cu Hub with braze wire grooves #2 #1 #3 #4 Initial plan to braze one long Mo shaft with raised hub to inner radius of Cu mandrel deemed unworkable Brazing HALF-LENGTH shafts to a COPPER hub piece and THEN brazing the Cu hub to the Cu mandrel deemed possible First test if Mo “backing ring” sufficient to keep Mo and Cu in good enough contact for a strong braze joint

34. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 34 / 55 Cu-Mo Hub Braze Test Assembly after 3 additional heat cycles (to mimic full assembly procedure) then sectioned. Moly-Cu Joint Declared “Good” by SLAC Braze Shop Experts, but….. Small holes held braze wire Grain boundary issues? Possible fracturing? Samples sliced & polished and sent to Physical Electronics lab for analysis: Fractures evident Cu-Mo joints we care about 1mm expansion gap

35. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 35 / 55 Details of Shaft attachment to the Collimator Interference Fit versus Improved Braze Braze Hub improvement includes a flexible Molybdenum end that prevents the copper Hub stub from pulling away from the Mo. Copper Jaw is constrained on the outside diameter with Carbon and when heated to ~ 900 degrees C is forced to yield so that upon cooling to ~ 500 degrees C the inner diameter begins to shrink onto the Mo Shaft resulting a substantial interference fit.

36. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 36 / 55 Full length Mandrel: In-House & Inspected –Most groove widths meet specification except for a few at each end. –Positioning of distorted areas could indicate damage was done by excessive forces imparted by hold down fixturing during machining. –Future Mandrel drawings will include a note warning about potential damage caused by excessive clamping forces. out of specification grooves

37. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 37 / 55 Exploded view of CAD model of Flex Mount Triple Cog Geneva Drive Wheel required for 512 clicks per facet U-Joint Flexes for Shaft “sag” and “Slewing” Water Cooling Inlet and outlet

38. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 38 / 55 Up Beam Flex Mount Assembly showing Ratchet and Actuator

39. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 39 / 55 Test Lab Preparation ~Finished Clean space with gantry access Basic equipment: Granite table, racks, hand tools Power supplies to drive heaters Chiller & plumbed LCW to cool jaw 480V wiring for heater power supplies required engineering review, safety review, and multiple bids (?!) Acquire Heaters 5kW resistive heaters from OMEGA PC & Labview Rudimentary software tests only National Instruments DAQ with ADCs Data Acquisition and Control Module 32-Channel Isothermal Terminal Block 32-Channel Amplifier Thermocouples Capacitive Sensors –Vacuum or Nitrogen (?) –Safety Authorization (!!!) Adjacent 16.5 kW Chiller Heater Power Supplies staged for installation in rack

40. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 40 / 55 CONCERN #1: Still have not brazed nor thermally tested a full length jaw assembly Main Steps Still Needed After 200mm Jaw tests Completed Satisfactorily Freeze brazing protocol Jaw 1/4 sections (16 needed of 24 now at SLAC) require slight modifications for braze gap requirements. Moly shaft (at SLAC) will perhaps need to be cut in two pieces and brazed to copper hub or interference fit made Drill Cu mandrel for Moly Shaft Wind coil using in-house SLAC Copper, –Need to order more (Finland 20 week delivery) OFE 10mm x 10mm or use CERN order of Ni-Cu alloy, anneal & wind mandrel Several braze Cycles Drill jaw to accept resistive heater –Understand (ANSYS) any change to expected performance

41. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 41 / 55 Concern#2: Still do not have a complete mechanical (=“RC1”) prototype Successful thermal performance of first full length jaw Complete the design of RC1 RF features Fit-up and initial tests of support/rotation mechanism on 1 st full length jaw Complete fabrication of second and third jaws (Glidcop?, Moly??) with full support assembly on the four corners Acquisition of Phase I support & mover assemblies –CERCA/AREVA REFUSES to supply SLAC –Recent (18 APR 07) proposal to sell SLAC a non-functional CERN TCS collimator with damaged tank & bellows Remodeling of CERN parts for interface to US parts –An enlarged vacuum tank has been modeled and some CERN support stand modifications have been identified No fabrication drawings have been done as yet Acquire motors, sensors,.. Not part of CERN TCS purchase

42. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 42 / 55 Vacuum tank, jaw positioning mechanism and support base derived from CERN Phase I beam

43. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 43 / 55 Inter-Lab Collaboration Good will & cooperation limited only by busy work loads –Regular ~monthly video meetings –Many technical exchanges via email –CERN FLUKA team modeling Rotatable Collimator –CERN Engineering team looking at SLAC solid-model of RC and independently doing ANSYS calculations of thermal shock –CERN physicists investigating effects of Cu jaws at various settings on collimation efficiency Participating in discussion of RF shielding design –SLAC Participation in upcoming CERN Phase II brainstorming meeting –Ralph Assmann to visit SLAC in summer 2007

44. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 44 / 55 Examples of CERN Collaboration on SLAC Phase II Design Luisella Lari Elias Metral Addressing RF Concerns Collaboration on ANSYS

45. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 45 / 55 Collaboration on Tracking Efficiency Studies Chiara Bracco - CERN Phase II collimators should provide x 2.5 improvement in global inefficiency Beam intensity limitations are due to losses in the dispersion suppressor above the quench limit. These losses are not improved by metallic secondary collimators Solutions must be found to improve performance of primary collimators

46. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 46 / 55 Resource Loaded Schedule Showing June 2008 for Full RC1

47. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 47 / 55 LARP Collimator Delivery Schedule DoneBraze test #1 (short piece) & coil winding procedures/hardware Prep heaters, chillers, measurement sensors & fixtures, DAQ & lab Section Braze test #2 (200mm Cu) and examine –apply lessons Braze test #3 (200mm Cu) – apply lessons learned Fab/braze 930mm shaft, mandrel, coil & jaw pieces 2007-09-011 st full length jaw ready for thermal tests Fab 4 shaft supports with bearings & rotation mechanism Fab 2 nd 930mm jaw as above with final materials (Glidcop) and equip with rf features, cooling features, motors, etc. Modify 1 st jaw or fab a 3 rd jaw identical to 2 nd jaw, as above Mount 2 jaws in vacuum vessel with external alignment features 2008-07-012 full length jaws with full motion control in vacuum tank available for mechanical & vacuum tests in all orientations (“RC1”) Modify RC1 as required to meet requirements 2009-01-01Final prototype (“RC2”) fully operational with final materials, LHC control system-compatible, prototype shipped to CERN to beam test

48. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 48 / 55 Phase II Task Summary There has been continued progress in design and excellent but slow progress on the necessary small scale projects to finalize procedures. Time estimates for thermal test of first jaw and construction of first 2 jaw prototype (RC1) are expanding. In June 2006 DOE was told “Expect thermal tests and completely tested RC1 device by end of FY06 and mid-FY07, respectively” Now need to say: “Expect thermal tests to begin and completely tested RC1 device by end of FY07 and end-FY08, respectively” Jeff Smith (Ph.D., Cornell) joins SLAC Collimation team ~July 23, 2007 –25% ILC, 75% LARP

49. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 49 / 55 Task #4: Irradiation Damage Assessment of LHC collimator materials: N. Simos 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 Status 2005-06: Irradiate 2D-weaved CC composite & measure CTE – DONE 2006-07: Irradiate Cu & Glidcop & measure CTE - DONE To Do: Measurements of Thermal Conductivity & Mechanical Properties NB1: 2006 exposure included graphite, super-invar, gum metal, Ti Alloy (6Al-4V), Tungsten Tantalum, AlBeMet, Graphite bonded to Cu & Ti In Progress: neutron exposure of 2006 Phase II collimator materials Plan: Finish “To Do” & analyze neutron irradiated samples to correlate results with proton irradiated data. In principle will allow for the use of the wealth of radiation data generated from reactor operations NB2: Nick (not LARP) considers ALL these materials as LHC relevant

50. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 50 / 55 CTE Measurements of Irradiated 3D C-C fluence ~ 10 20 protons/cm 2 Irradiation Damage Self Anneals through thermal cycling as seen in 2-D C-C

51. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 51 / 55 CTE Measurements of Irradiated Copper fluence ~ 10 21 protons/cm 2

52. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 52 / 55 CTE Measurements of Irradiated GlidCop fluence ~ 10 21 protons/cm 2

53. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 53 / 55 Carbon Composite & Graphite Damage fluence ~ 10 21 protons/cm 2 3-D carbon 2-D carbon Graphite

54. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 54 / 55 Conclusions-Platitudes 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

55. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 55 / 55 Conclusions-Pessimistic No real work has happened at BNL to understand RHIC data until recently. Progress may be made soon, but will analysis of existing RHIC data really add anything to LHC design at this point? FNAL Tertiary collimator simulations too little, too late: Main choice (W vs. Cu) made, collimators fabricated & installed. These studies will never be truly over. Is that so bad? BNL irradiation studies support 2-D C-C for Phase I (after the fact) and Cu/GLIDCOP for Phase II (after the fact). Not all measurements of relevant physical properties made yet. Part of an ongoing study of encompassing many materials of general academic but not necessarily LHC-relevant interest. SLAC team working hard but: –Thermal mechanical tests > 1 year late: what will happen if they do not deliver performance –Need to start construction of “RC1” at beginning of FY08 –Need CERN mover assembly as there is no way we can re-manufacture so many parts –Need other improvements (to primaries?) to improve quench limit –CERN to provide 2 Phase II secondary collimator designs. What then?

56. Bonus Slides

57. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 57 / 55 Specification Changes Relative to April 2006 Design

58. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 58 / 55 Heat deposited in major components (W/m^3) in 1 hr beam lifetime operation

59. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 59 / 55 Major jaw dimensions and calculated cooling performance

60. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 60 / 55 One Year Later… At June 2006 DOE Review we introduced New jaw-hub-shaft design which eliminates central stop & flexible springs New reverse-bend winding concept for the cooling coil which eliminates the 3 end loops, permitting longer jaws and freeing up valuable space for jaw supports, rotation mechanism and RF-features Internally actuated drive for rotating after beam abort damages surface Main accomplishments in the last year Many test pieces manufactured and examined, tooling developed, and, especially, brazing protocols worked out Hundreds of 3-D concept & 2-D manufacturing drawings made Rotation & support mechanism fully designed and manufactured All parts for first full length jaw assembly manufactured & in-house Test lab fully wired, plumbed and equipped BUT… –Still have not brazed nor thermally tested a full length jaw assembly –Still do not have a complete mechanical (=“RC1”) prototype

61. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 61 / 55 Summary of New Baseline Configuration Jaw consists of a tubular jaw with embedded cooling tubes, a concentric inner shaft joined by a hub located at mid-jaw –Major thermal jaw deformation away from beam –No centrally located aperture-defining stop –No spring-mounted jaw end supports Jaw is a 930mm long faceted, 20 sided polygon of Glidcop Shorter end taper: 10mm L at 15 o (effective length 910mm) Cooling tube is square 10mm Cu w/ 7mm square aperture at depth = 24.5 mm Jaw is supported in holder –jaw rotate-able within holder –jaw/holder is plug-in replacement for Phase I jaw Nominal aperture setting of FIRST COLLIMATOR as low as 8.5  –Results in minimum aperture > 7  in transient 12 min beam lifetime event (interactions with first carbon primary TCPV) –Absorbed power relatively insensitive to aperture: for 950mm long jaw p=12.7kW (7  ), p=12.4kW (8.23  ) Auto-retraction not available for some jaw orientations Jaw rotation by means of worm gear/ratchet mechanism  “Geneva Mechanism”

62. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 62 / 55 Cu-Mo Hub Braze Test parts #1 - Mandrel Dummy (not shown) #2 - Mo Shaft Dummy #3 - Mo Backing Ring #4 - Cu Hub with braze wire grooves #2 #3#4

63. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 63 / 55 Up Beam Flex Mount – Rotation Assembly Complete Design features that may not be apparent in the photos include: –Integral water cooling channel. –Flexibility for length increase of the Collimator Shaft (proton load). –Compensation for Shaft (in-plane) end angle rotation (sag). –Flexibility for the +/- 1.5mm offsets required during “slewing”. –Does not require an extra drive and control (uses existing systems). –2.5mm motions advance the ratchet 1 “click”. –512 “clicks” advance the Collimator to the next facet. –Facet advancing is ~5% of the lifting load for Vertical Collimator

64. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 64 / 55 PLASTIC DEFORMATION of ENTIRE JAW after a BEAM ABORT ACCIDENT? PRELIMINARY RESULT: –0.27 MJ dumped in 200 ns into ANSYS model –Quasi steady state temperature dependent stress-strain bilinear isotropic hardening –Result: plastic deformation of 208 um after cooling, sagitta ~130um –Jaw ends deflect toward beam Jaw surfaces at 90 to beam impact useable, flat within 5 um Doyle 54 um Beam side Far side Melted material removed

65. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 65 / 55 Rotatable Collimator Activation & Handling Need dose rate at ~1m; Mokhov et al

66. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 66 / 55 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

67. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 67 / 55 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 Specimens highly degraded under dose >> LHC collimator jaws will see.

68. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 68 / 55 CTE Measurements of Irradiated 2D 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 LHC collimator operating temperature regime

69. LARP DOE Review - 05 June 2007Collimation Tasks - T. MarkiewiczSlide n° 69 / 55 Irradiation damage assessment – to date While all carbon composites tested (2005-2007) exhibit stability in their thermal expansion coefficient in the temperature range they are expected to operate normally, they experience a dramatic change in their CTE with increased radiation. However they are able to fully reverse the “damage” with thermal annealing Carbon composites also showed that with increased proton fluence (> 0.2 10^21 p/cm2) they experience serious structural degradation. This finding was confirmed for the family of such composites and not only for the 2-D composite used in the LHC. It was also experimentally shown that under similar conditions, graphite also suffers structurally the same way as the carbon composites Proton radiation was shown to not effect the thermal expansion of Copper and Glidcop that are considered for Phase II Encouraging results were obtained for super-Invar, Ti-6Al-4V alloy and AlBeMet In Progress: Set up of existing tensile test apparatus & test of irradiated C-C Set up of new thermal conductivity apparatus