LARP Collimator Tasks Summary 28 April 2006 LARP Collaboration Meeting-LBL Tom Markiewicz SLAC BNL - FNAL- LBNL - SLAC US LHC Accelerator Research Program

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 2 / 27

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 3 / 27 Take Home Points Phase II Rotate-able Collimators –Elevated to “Hard Deliverable Status” in eyes of our CERN colleagues –Schedule slippage of ~6 months Manpower issues Review committee issues (more complete design before can start) –400k$ returned to LARP general fund –Now on track & better staffed –Consensus that we need more effort to understand 1 MJ beam-abort on jaw Communication with CERN slower than ideal (see Nikolai’s comments later) –Should we ask Ralph to appoint a “Point of Contact”? New Task 5 proposed: Crystal Collimation –To be examined by Gang of 5+1: (4 x L2 + VS) + S Impact on “baseline” secondary collimator

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 4 / 27 Task 2: Progress Since October 2005 Meeting State of affairs Oct. 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 Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 5 / 27 RHIC Tracking Results Ions Agree With “ICOSIM” Protons Data does not agree

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 6 / 27 TERTIARY COLLIMATORS- October 2005 Status Tertiary collimators (TCT) at 8.4  around IR1/5 protect SC triplets from tertiary halo coming from particles leaking from 7  secondary collimators, upstream beam-gas and inefficiency of MPS if unsynchronized beam abort. These must not induce peak energy deposition in the triplets above the quench limit nor induce detector backgrounds. 80 x 25 x 1000mm Cu jaws at.4s 145m from IP added to MARS15 Without TCTsWith TCTs

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 7 / 27 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 Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 8 / 27 TERTIARY COLLIMATORS PROGRESS & PLANS In October 2005, Nikolai wrote: –File of Beam1 loss in TCT region calculated by CERN received Need similar file for Beam2 Need similar files for momentum cleaning insertion IR3 –Plan to begin updating results using these files beginning mid-October Today Nikolai writes  Need input from Ralph ASAP - it’s not the first time – obviously a communication issue  As soon as beam loss input files received  ~2 mos to finish most work on TCT  If no surprises – task can be closed ~1/2 yr 6 months without requested information

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 9 / 27 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 (117 & 200 MeV protons) Measure material properties: thermal expansion, mechanical properties, thermal conductivity/diffusivity and thermal shock BNL Hot Cell Sample Measurement Facility Status October 2005: –Phase I Carbon-Carbon irradiation completed –Sample activation measurements completed –Thermal Expansion of specimens started Specimens highly degraded under dose >> LHC collimator jaws will see.

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 10 / 27 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 Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 11 / 27 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 Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 12 / 27 New Measurement Equipment Mechanical Testing Equipment (Stress vs. Strain) to be reintroduced to the Hot Lab + 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 Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 13 / 27 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 Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 14 / 27 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

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 15 / 27 Status of Phase II Rotating Collimator Project at Pheasant Run LARP Mtg. SLAC and CERN agree on an initial set of specifications for the first mechanical prototype RC1 –Put a new vacuum tank with cylinder jaws that fits LHC spatial constraints on a CERN Phase I base and use CERN Phase I scheme for jaw alignment and cooling input –Provide 12kW cooling to each 136mm x 95cm jaw through flexible tubing –Relax 25um flatness tolerance but provide flexible jaw support and a central stop mechanism to ensure thermal bowing is AWAY from beam 400 um sagitta for 1 hr beam lifetime engineering steady state 1200 um sagitta for 12min beam lifetime 10 second transient

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 16 / 27 FY06 Goals of Phase II Rotating Collimator Project and Beyond Work Plan outlined 10/6/ Single jaw thermal test: one jaw with internal helical cooling channels to be thermally loaded for testing the cooling effectiveness and measuring thermal deformations. 2.Full RC1 prototype: a working prototype for bench top testing of the jaw positioning mechanism, supported to simulate operation in all necessary orientations, but not intended for mounting on actual beamline supports with actual beamline, cooling, control and instrumentation connections. Deliverables listed 10/6/ Final version of RC1 CDR: Awaiting support/stopper design 2.External review of RC1 CDR: √ 3.Construction & Performance report on RC1: X  mid FY07 Progress delayed ~6 months due to reviews & manpower issues

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 17 / 27 Jaw/Cooling Tube Joint Development Purpose: determine appropriate joint configuration & fabrication methods In process.. target completion date Square hollow magnet conductor for first test ~ 9 mm x 9 mm Copper jaw and mandrel Cu-Au braze After first braze, machine coil o.d. for correct fit to jaw i.d. After second braze, section assy to inspect coverage Round tubing with grooved (?) mandrel is next May 9 th Cooling Tube Jaw Center Mandrel ~100 mm ~70 mm dia ~100 mm dia

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 18 / 27 Single Jaw Thermal Test setup Reference bar, water cooled to maintain straightness (radiation shield ?) Standoffs fix jaw distance to reference bar at center Capacitive proximity sensors at ends Flexible end mounts 2 x 5 kW heaters, coupled with thermal grease Orientation: may be rotated 90 o, or 180 o or on end Thermocouples measure temperature distribution Water cooling

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 19 / 27 Single Jaw Test Thermocouple Locations Thermocouples recessed into Jaw slightly below the surface Spaced along Heater length and around Jaw circumference Should yield the Jaw heating profile predicted by the FE analysis 12 x Thermocouples 2 x 5kW Heaters

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 20 / 27 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 Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 21 / 27 Unresolved Jaw Support Issues Support needs to: hold ~100kg jaw to 5-10um accuracy not sag under gravity for vertical and skew orientations permit ~1200 um flex for 10 second bursts of 60kW energy deposition work with torque of Phase I stepping motors

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 22 / 27 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 Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 23 / 27 Unresolved Central Stop Issues Interplay between alignment scheme independent motion of each end of each jaw and stop must be on beam centerline this can vary ±5mm/ store Reproducibility of alignment on successive stores May use two stops to control tilt Slot deep enough to avoid damage in accident Stop far enough from beam to never be damaged & is out of way at injection

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 24 / 27 Unresolved Issues with Jaw Rotation Torque required to rotate 360 understood and is substantial; Coil “creep” may alleviate. Details of actuator not yet worked out Interference with RF parts and gross jaw adjustment during injection not studied

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 25 / 27 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 Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 26 / cm Missteered beam (9E11 protons) on secondary Jaw Copper Jaw Cross section at shower max. Copper Fracture temp. of copper is about 200 deg C What is the damage area in a missteering accident? FNAL Coll with.5 MJ ~1MJ

LARP Collaboration Meeting Apr Collimator Task Summary - T. Markiewicz Slide n° 27 / 27 Phase II Task Summary Project has slipped 6 months in 6 months due –Reality of hard deliverables as opposed to softer “design” milestones –Difficulty/cost of acquiring manpower –Understandable design requests by review committee Nothing we didn’t know about Budget “slipped” 6 months as well After taking this hit we believe we are on-track to deliver on new schedule –Most 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 Expect thermal tests and complete design 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.