28 October 2008LARP CM11, FermilabTom Markiewicz/SLAC
BNL - FNAL- LBNL - SLACUS LHC Accelerator Research ProgramShort Status ReportRotatable CollimatorT980 Crystal Collimation at TevatronUA9 Crystal Collimation at SPSCritical IssuesCost to complete, schedule, technical risk, interface with CERN plans & activities, APL, FY10 and beyond, .
Rotatable CollimatorBuild one collimator jaw and test with 10kW resistive heaters to verify thermo-mechanical performance: COMPLETEBuild a full working 2-jaw collimator and after lab qualification, subject it to beam tests at CERN: IN PROGRESSRobustness in new devoted beamlinePerformance
Final Jaw Braze 22 April 2008
Machine Flat Facets and Groove for Heater TestFinal brazing was a success!
Flat facets and grooves for heater tests and thermocouple holes havebeen machined.Within 25 micron tolerance along facet surface.
10kW External Heater Thermal Test SetupHeater cableWater flow controlJaw in support standHeaters strapped on jawWater flow tubeExtra heater
Comparison of Sagitta & Temperature with ANSYS as a function of angle with respect to heaterJaw with two 5 kW heaters modeledIncludes accurate representation ofWater flow/temp changeMaterial propertiesThermal expansionHeat flow / thermal conductivityData ~10% larger than ANSYS
Results of Bake-Out test: 1.2E-09 torr for 1 jaw in a vacuum vessel and Clean RGA after standard PEP-II 200C ProcessZero hydrocarbons (mass >40)
Final Prototype ConstructionMaterial, fabrication & contracts for jaws in progressWe are planning for enough parts for 3 jaws when 2 are needed6 Moly half shafts ordered July 17; 3 arrive (damaged) Oct 13Large order of Glidcop for jaws placed Oct 2 with Dec 9 deliveryMulti-stage contract for mandrel (and all other) precision machining being negotiated: critical path: bids hopefully Nov 17Design changes to jaw support and jaw fabrication procedure
RF impedance tests/calculations & continually evolving RF design
RF DesignLow resistance RF contactSlot for Spiral RF Spring
Short RF Test Jaw with End Socket mountedBearing RaceSiN4 ballsUNDER STUDYContact Resistance MeasurementsStretched Wire Impedance MeasurementsTrapped mode study using Omega3P
T980 Crystal Collimation at TevatronGreatly improved T980 hardware and beam diagnostics installed in the Tevatron tunnel on August 28, 2008
T980 Crystal Collimation at TevatronFirst End-of-Store studies on Sept 14 and Oct 3, 2008
Crystal aligned First angle scan produces channeling results!
Fixes and improvements in the tunnel on Oct. 23.Request for next EOS for October 30-31.
T980 Crystal Collimation at TevatronManagement DiscussionsSupport of Phase I goals/plans (until Spring 2009): Measure channeled, volume-reflected and scattered beams as well as beam losses downstream of the crystal setup in comparison with simulations. Demonstrate reproducible beam loss reduction in the B0 and D0 in comparison with simulations, aiming at a routine use of crystal-based collimation in the Tevatron stores.Plans for Phase II (>Spring 2009) are subject to another review and 2009-2010 Collider Run plans.
Interplay and Timecales of T980 and UA9
UA9: Crystal Collimation at SPSPost CM10, executive decision to commit $200k of FY08 uncommitted funds to SPS Crystal experimentSynergy of equipment and peopleSecure single particle crystal study in event Tevatron Phase II of T980 does not happenUS to provide Roman Pot#2 ($100k) and detectors ($100k)
Progress & Plans of UA9Roman Pot#2: ballisticSLAC engineers modify detector mount and overall dimensions of existing RP design, begin buying vacuum components, contract mechanical designer, US and European vendorsSilicon detectors, PIN Diodes:Discussions in progress, mediated by PeggsComo group (Prest) for silicon detectorsFNAL (Mokhov, Tsesarek) for PIN diode systemAdministrative: MOUs, Team $ accounts: In progressCollaboration: 2 circles of communicationWeekly WEBEX with SLAC, BNL, CERNAsynchronous bilateral interactions between BNL, CERN, SLAC, INFNPhysics studies, prep for data analysis, etc.
Issues Critical to ALL of LARPRotatable collimator has been single costliest Accelerator System activity in FY2008 and FY2009 (950k$ each year)~1/3 of the Accelerator Systems budget
Hard Deliverable of functioning prototype due just early in FY2010
LARP highly desiresOn time, under budget completionTechnical successWhat are risks and how do we manage them?
Post Prototype Delivery Collimation ProgramContinued involvement in Phase II Collimation projectIf RC chosen for some of the 30 Phase II slotsIf RC not ChosenLARP or APL?
Performance RisksWill thermal-mechanical testing of the first jaw validate the shaft-hub-jaw design that should limit maximum jaw deflection into the beam area to 230 microns for 10 second bursts of 60kW beam absorption
Will the mechanical accuracy of the device be adequate (40 um)
Will the basic jaw-adjustment and jaw-rotation work as planned
Will the effective impedance and RF characteristics of the jaw and the transition to the vacuum tank aperture be adequate
Will the device vacuum be sufficiently low
When damaged by an aborted beam, will the extent of damage be sufficiently localized to allow rotation to a clean surface, as planned
Issues (1)RC project targets end of CY09 LHC run as delivery date for prototypeTechnical problems always as possibilityExample: For test jaw 1st mandrel destroyed by vendor and 2nd mandrel damaged, but recovered, in a brazing faux pasExample: Production shafts arrive late, incomplete & damaged
Planning of High Intensity Test Beam (TT60) for robustness tests beginningCompletion targeted for 2010Tests in 2010-2011 (6-9 months later than current plan)
SLAC had de-scoped to one test jaw and one prototype, need to plan for what gets destructively tested and what can be tested in LHC2 prototypes?1 prototype and a hunk of copper in a 2nd vacuum tank w/steppers?Removable insert for robustness tests + full prototype?
Issues (2)Technical inadequacy of SLAC designScope creep: Integrated BPMs part of CERN design, not (yet) SLACs(Mis)communication: Respect all agreements: No braze joints in vacuumNo Beryllium1E-9 level vacuumCu-Ni tubing instead of OFE Copper for water coolingImproved external mechanics and lessons learned from Phase IWritten & signed technical handshake advised
Interface with APLNew tertiary collimators: no idea whatPhase II secondaries: state mission need as placeholderPhase II primaries: 1st mention (for me)Cryo-collimators: CERN-GSI onlyAdvanced: Crystal, Electron lens not in APL, R&D continues
Issues (3): FutureT980 and UA9Natural tendency is to continue this research up to and including installation of crystal scrapers in LHCAfter FY08-09 M&S outlay, budget is (as usual) manpower & travelWhether, when or how to sunset this activity
RC: as planned and often shown2009:Finish all parts and assemble into a vacuum tank compatible with Phase I adjustment mechanism = RC; Mechanically test RC, ship and install in SPS/LHC2010:Collimator tests at LHC & Final drawing package for CERN2011:Await production & installation of chosen design(s) by CERN2012:Commissioning support