LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 1 /6n LARP Phase II Secondary Collimator RC-1 Mechanical Design Review 01/04/09

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 2 /6n Introductory Statements Your comments and/or questions are welcome at any time. There will also be time at the end for an in-depth discussion of any and all aspects of our design. Sub-title of this talk: “The Rotatable Collimator from the inside out” Basic format I hope to follow: Internal component detail (CAD models and photos of real pieces (RC-0 / RC-1) Fabrication photos of components of the RC-0 Jaw aka Heater Test Jaw. Fabrication photos of some of the RC-1 components that are currently in work. Specifications and physics requirements and how we meet them.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 3 /6n Collimator Jaw-Hub-Shaft Concept Jaw heats up along the side facing the beam and lengthens causing each end to deflect away from the beam and into the 2mm annular gap between the Shaft and the Jaw. The Jaw also swells a bit causing the Jaw face move towards the beam.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 4 /6n Some Calculations Jaw heating and deflection characteristics for Steady State (SS) and Transient (TR) conditions Component SS TR units Max jaw temp C Max deflection toward beam μ m Surface Sagitta μ m Effective length m Water temp rise 20.3 C Water pressure drop 2.4 bar

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 5 /6n Cutaway of Jaw Assembly

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 6 /6n RC-1 Half Shaft and Hub Assembly Inner Keeper Ring Forces moly inner fingers to keep up with Glidcop expansion during brazing Outer Keeper Ring Keeps moly outer finger tips from splaying out and away from Glidcop during brazing Cu-Au alloy braze wire This Outer Keeper Ring is machined off after brazing in order for Shaft to pass through Mandrel ID This Outer Keeper Ring acts as a stop to position the Shaft longitudinally

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 7 /6n RC-1 Molybdenum Shafts

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 8 /6n Details of Ends of Molybdenum Half Shaft

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 9 /6n RC-1 Hollow Glidcop Hub (prior to Cu plating & grooving)

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 10 /6n Grooving details of Glidcop Hub

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 11 /6n RC-0 Half Shaft and Half Hub Brazing The two Half Hubs are now one. We originally needed to machine out a copper inner keeper plug that forced the moly fingers out with the Glidcop during brazing to provide an opening for the tubing. RC-1 uses a thinner SST ring that can remain inside the Shaft with room for the tubes to pass through.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 12 /6n Mandrel with Cooling Tube

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 13 /6n RC-0 Mandrel at QC

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 14 /6n RC-1 Mandrel in work

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 15 /6n RC-1 Mandrel almost finished (March 15th)

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 16 /6n Completed RC-1 Mandrel March 25th

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 17 /6n No Vacuum to Water Joints Tubing is wound into Mandrel groove while free ends pass through the hollow center parallel to each other yet exiting on Shaft centerline. When Collimator rotates the tubes twist on their own axis but not around each other.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 18 /6n Tubing coil on turntable for winding 16m of tubing are removed from “loose coils” UHV cleaned and placed on a turntable for payout.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 19 /6n Winding tubing on the RC-0 Mandrel

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 20 /6n Nearing the end or… forming the bend

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 21 /6n RC-0 Mandrel Brazing Setup

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 22 /6n Machining the RC-0 Mandrel to size

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 23 /6n Collimator Jaw Brazed to Mandrel RC-1 Jaw has 5 cylindrical sections. End sections are tapered. RC-0 has 16 quarter sections, none are tapered. The RC-0 Jaw to Mandrel fit up for brazing was quite time consuming & expensive. Each quarter section had to be reworked to fit Mandrel final diameter! Changing to full cylinders, to save time & cost, meant they should be a somewhat shorter to be easier to slide over the Mandrel with the tight brazing tolerances. Robustness test will use 1 RC-0 and 1 RC-1 style Jaw

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 24 /6n 16 Jaw Quarters with Cu/Au alloy foils

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 25 /6n Jaw Braze preps continue

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 26 /6n RC-0 Jaw Brazing Success

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 27 /6n RC-1 Jaw braze Assembly

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 28 /6n Section of Revised Jaw Cu-Au braze wire go here ~ 40 snap rings Braze wires replace foils simplifying braze preps

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 29 /6n RC-1 Final Machining

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 30 /6n 20 Facets 20 years? 20.25mm Thickness of Glidcop Jaw (facet to water) is 24.5mm. ~15 degree taper at each end places RF contact bearings ~10mm away from facet. Facet length = 930mm (oal) – 2x38mm (taper) = 854mm Taper may be too generous and could be shortened for a longer facet.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 31 /6n Facet Flatness Flatness Specification is 25 microns over full length of Jaw. –How did we do? Generally very good (4 of 5 facets checked met spec). Worst facet has a sagitta of 43 microns. –How we will do even better! Newer milling machine. –Competitive bid with specification of 25 micron rather than “best effort” May suggest vendor perform test mill of dummy piece to qualify process prior to fab.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 32 /6n Jaw Facet Preliminary measurement for end-to- end flatness

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 33 /6n Measuring RC-0 Jaw facet flatness

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 34 /6n Link to RC-0 Facet Flatness data

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 35 /6n Up Beam end Jaw Support Version 1 Diaphragm allows Jaw end-to-end offset and Shaft sag. Flex vanes compensate (along with the diaphragm) for Shaft expansion

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 36 /6n Jaw Support Development A few thoughts: Rigid mount would hold drive gearing in alignment with Shaft. This would require a flexible connection to the shaft to allow for deflection (sag) due to gravity and Jaw end-to-end offset. Or a spherical bearing. At the time we were unable to locate a full complement ceramic spherical bearing set. So… A diaphragm was introduced to attach the gear to the Shaft. This diaphragm, if designed correctly, should be able to distort not only for the angles but also for the change in length of the Shaft due to thermal effects. Eventually it was determined that the End Support would need to flex to help the diaphragm absorb the longitudinal expansion. Version 1 was designed. Finally the current version combines the diaphragm angular distortions with the flexibility of the original End Support. The final hurdle is to find an acceptable high strength stainless steel to fabricate it from. (Restrictions may eliminate some H.S. stainless steels which contain Co as an alloying element).

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 37 /6n Up Beam Jaw Support Current Version

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 38 /6n Down Beam Jaw Support Current Version mm dia. ceramic ball bearings roll between these two races

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 39 /6n Cutaway of Jam Nut and Support Jam Nuts mate at beveled surfaces to strengthen tip of Support Rotation Mechanism mounts to tab on bearing race 100 1mm dia. Ball bearings roll in “V” groove

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 40 /6n Outboard Bearing Race/Axle Buttress Threads 100 1mm ceramic ball bearings roll here

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 41 /6n Inboard Bearing Race w/gear Drive mounting tab Bearings roll here

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 42 /6n Jam Nut Two of these lock Collimator Jaw to the End Support

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 43 /6n Shaft Ends are grooved for ceramic ball bearings Ceramic bearings roll here and at far end

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 44 /6n Shaft End bearing groove details Bearings roll here

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 45 /6n Jaw End Support System w/cooling tube (Bellows removed to show support detail) Flexible support is high strength stainless steel welded to bottom of bellows cuff at assembly to Tank Base Plate Jaw Shaft End rests in slot of Support and is held by jam nuts on either side ~100 1mm dia. ball bearings in End adapter for rotation Bellows mounting to Drive is unchanged from CERN design Cooling tube adapter is tig welded after Jaw is installed in Tank “ Beefed-up” design still permits Jaw end-to-end offsets (3mm), Shaft thermal expansion and static sag. Deflection is improved for non-horizontal collimator positions.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 46 /6n Jaw Rotator/Gear Drive Accuracy Jaw face alignment specification dictates an indexing type of mechanism. This drive allows up to 8 mis-counts of drive motor steps before Jaw moves off position. 2x1 bevel reduction in combination with 80 x1 worm reduces side load on drive and support to a minimum level. Worm also provides locking of Jaw. Backlash is a minimized due to tubing torque load

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 47 /6n Indexing the Collimator Jaw Indexing can be 1 facet, 5 facets for 90 degrees, 10 facets for 180 degrees. For a distortion of Jaw in the plane of the beam a 90 degree advance would render the distortion a non-problem. After a 180 degree advance a subsequent hit might correct the distortion, if a were of the same magnitude. Following a sequence of 10 facets (180 degrees), 1 facet then 10 facets, a total of 5.25 twists of the tubing would be needed to “use up” all 20 facets. Tubing was twisted an equivalent of 8 times. No visible defects observed.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 48 /6n Twisted Hollow Copper 10mm x 7mm

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 49 /6n Ratchet actuation conceptual arrangement Hammer contacts here during over-travel of Jaw Wire Springs restore Hammer after ratchet movement

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 50 /6n Jaw End Details for Image Current connection 300 Rhodium Plated stainless steel ball bearings roll here Bearing races fit in recess here

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 51 /6n Image Current Bearing Race (example) Glidcop Ring details are similar for both races

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 52 /6n Image Current Foil Assembly Version 1 Height of parts was necessary to shadow the Gear Drive on top of Jaw End Support This surface mounts to bearing race

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 53 /6n Current Version of Foil Assembly Temp sensor mounts here Reduced height of foil is minimum to shadow “Geneva”

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 54 /6n Temperature Sensor/ Image Current Foil mount Foil Brazes Here Temp Sensor mounts here Mounts to Bearing Race here

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 55 /6n Current Version of Image Current Foil 1mm x 40mm Glidcop foil will be life cycle deflection tested This end curves to conforms to Mount for brazing This end curves to conform and attaches to Beam pipe Flange ID

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 56 /6n Preliminary Tank concept First transition from round pipe to square geometry is machined into the flange end of tank. Flexible Glidcop foils (not shown) carry image current to second transition which tapers meet Jaw end. Tank has tapered features to prevent upsetting the image current

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 57 /6n Why the change? We were interested in the ability to work on the image current components after things were welded up because we may not get it right the first time. Results from preliminary laboratory RF tests showed that geometry to be less an issue than previously anticipated so the more complicated transitions may not be needed. We will be hand tig welding the tank together rather than e-beam welding so distortion could be less of an issue. Pluses: Uses standard pipe. Thinner wall results in less radiation effects. Camera ports for viewing the Jaw face remotely seem a bit simpler to implement. Minuses: However, HOM modeling has recently shown high heating loads (larger volume). Until those issues are resolved this configuration might only be useful for the TT60 tests.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 58 /6n New Cylindrical Tank Concept

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 59 /6n Cylindrical Tank body Tank is 355.6mm diameter x 6.35mm wall welded pipe Material is 304 SST. Note: Weld seam will be eliminated by cutout at bottom.

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 60 /6n Base Plate Base Plate is only slightly larger than CERN design

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 61 /6n End Flange Tank End Adapter reduces the Tank dia to a DN250 CF Flange Material is 304LN, if required, otherwise 304L

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 62 /6n Beam Pipe Adapter End Flange reduces the DN250 CF Flange to DN100 Beam pipe Flange Material is 304LN, if required, otherwise 304L. Note: Small hole is for the Camera Viewport Nipple

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 63 /6n Assembling the Tank for welding End Flanges could be tack welded to cylinder first Fixturing holds Cylinder rigid To retain shape during welding Collimators were previously assembled to Base Plate and welded into bellows end cuff All viewports are previously welded in

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 64 /6n Proposed TT60 Robustness Test Configuration Preferred orientation is 0 degrees. RC-0 & RC-1 Jaws are used. Collimator mounts on CERN stand. –Cooling water quick connect? –Cables do not? Laser micrometers mount here for measuring possible permanent distortion after beam strike End ports are 1mm thick titanium. Vacuum pump (if needed) mounts to tee at down beam end. Chain tensioners used on all flanges. Cameras mount here (both ends) for remote viewing surface damage to RC-1 Jaw after beam strike Beam DN250 flanges at ends permit access prior to test and after “cool-down period”

LARP LHC PHASE II COLL RC1 - S. Lundgren 1 April 2009 No 65 /6n Bonus Slide