1. C. Garion Presentation Outline  Overview of the inner triplet interconnections  Q1/Q2, Q2/Q3 interconnections  General view  Working conditions  Compensation system  Stability issue  Vacuum vessel closure  Q3/DFBX, D1/DFBX interconnections  Jumper connections  Quality assurance  Interconnection status  Conclusions Interconnections

2. 2/18 Inner triplet review 24/4/07 C. Garion Overview of the IT interconnections D1DFBXQ3Q2Q1IP Jumpers to the QRL  Triplets installed at points 1, 2, 5 and 8, Left and Right  2 interconnections between magnets: Q1/Q2, Q2/Q3  2 interconnections between magnet and DFBX at points 2 and 8 ; 1 interconnection between magnet and DFBX at points 1 and 5  2 interconnections between DFBX and QRL (jumpers)

3. 3/18 Inner triplet review 24/4/07 C. Garion Q1/Q2, Q2/Q3 interconnections Beam line (V) Beam screen line (K) Main bus bar line (M1) Instrumentation line (M2) General view Cold mass/heat exchanger line (M4) Heat exchanger line (L) Pumping line 2 (Xbt) Thermal shield return line (FF) Thermal shield cooling line (EE), filling line (LD) and pumping line (XB) are not visible on this photo. Q3 Q2 4.5 K heat intercept line (C’)

4. 4/18 Inner triplet review 24/4/07 C. Garion Q1/Q2, Q2/Q3 interconnections Working conditions LineTemperature [K] Design pressure [bar] Maximum IC stretch [mm] Cold mass: M1, M2, M4, L, LD, 1.92030 XBt, XB4.5430 C’4.52030 Thermal shield: EE, FF 50-7022~40 mm Beam screen: K 4.5-202025.8 (nominal) 34.2 (exceptional) Beam: V1.9 / 20125.8 (nominal) 34.2 (exceptional)

5. 5/18 Inner triplet review 24/4/07 C. Garion Q1/Q2, Q2/Q3 interconnections Interconnection and compensation system L sleeves Fixed point XB%L XB sleeves M4 sleeve New H piece Main line connection LineCompensationWeld type XB1 universal joint + 2 sleeves4 lip welds L2 bellows + 2 sleeves4 lip welds M41 bellows + 1 sleeve3 lip welds M1, M2Welded bellows2 filled welds LD, XBt, EE, FF1 bellows2 filled welds Plug in module1 bellows2 lip welds C’, K1 metal hose2 filled weld Comments: 1.All welds and welders have been qualified (CERN/SC, CERN/TS). 2.Few minor modifications have been implemented w.r.t. initial design (adaptation rings) Modified with respect to initial US design after 7-8 pressure test

6. 6/18 Inner triplet review 24/4/07 C. Garion Q1/Q2, Q2/Q3 interconnections Interconnection and compensation system Mean diameter [mm] Length [mm] Number of convolutions Number of ply Ply thickness [mm] Axial stiffness [N/mm] L181.152983630.36391 M490.7595.51030.4330 E92.52*682*830.4194 LD, EE, FF67.6169.8830.31171 M1,M2113.051276410.2512 Xbt111.82461620.25453 V113.5981410.1520 Bellows main parameters

7. 7/18 Inner triplet review 24/4/07 C. Garion Q1/Q2, Q2/Q3 interconnections Stability issue - Local stability (at the component scale) Buckling pressure [bar] (without restraints)Comments L100 (column buckling)Protecting shells M495 (column buckling)Restraints E~100 (external pressure) ~ 200 (internal pressure, single bellows) ~ 42 (internal pressure, universal joint) Bellows without restraints LD, EE, FF~80 (column buckling)Protecting shells M1,M2~1-5 (column buckling)Restraint system developed and tested by FNAL Xbt~29 (column buckling)Protecting shells Xb (copper tube) ~84 (collapsing external pressure) V~5 (collapsing external pressure)

8. 8/18 Inner triplet review 24/4/07 C. Garion Q1/Q2, Q2/Q3 interconnections Stability issue - Global stability (at the IC scale) ModePressure [bar] 38.5 48 Cold mass and heat exchanger Initial design Higher mode at ~60 bars Buckling mode for Q1/Q2

9. 9/18 Inner triplet review 24/4/07 C. Garion Q1/Q2, Q2/Q3 interconnections Stability issue - Global stability (at the IC scale) Cold mass and heat exchanger Modifications First global mode: 49.5 bars (Q1/Q2)  1 mode suppressed  First mode with limited displacement  Critical pressure of ~49.5 bars for Q1/Q2 and ~49 bars for Q2/Q3 (rescaling)  Assembly of H pieces done by welded sleeves  minimum of shear pres- stress in the bellows Stiff restrain on M4 bellows

10. 10/18 Inner triplet review 24/4/07 C. Garion Q1/Q2, Q2/Q3 interconnections Stability issue - Global stability Pcr ~30bars Pcr ~60bars Guiding device to be installed on the end plate LD Q1 Aluminium plate Interconnection support EE, FF bellows Pcr ~50bars Thermal shield extremity Thermal shield: “Soft” boundary conditions Pcr ~39.5bars

11. 11/18 Inner triplet review 24/4/07 C. Garion Q1/Q2, Q2/Q3 interconnections Vacuum vessel closure Vacuum longitudinal force: Max 8000daN Buckling force (per rod): 5770daN Buckling force (per rod):1440daN Is the guide length sufficient to avoid rotation? Stiff guidance has probably to be implemented Bellows buckling pressure: 3.7 bars 4.8 mm thick

12. 12/18 Inner triplet review 24/4/07 C. Garion D1/DFBX, DFBX/Q3 interconnections V line Bus bar line No structural modification of original US design (except Xb fixed point Q3 IP)

13. 13/18 Inner triplet review 24/4/07 C. Garion D1/DFBX, DFBX/Q3 interconnections Line Q3/DFBXD1/DFBX Contraction [mm] Compensation element Location of compensation element Contraction [mm] Compensation element Location of compensation element Beam (V)19.4bellowsInterconnection19.3BellowsInterconnection BS (K)19.4hoseInterconnection19.3hoseInterconnection Bus bar~20.5bellowsInterconnection~ 17.6bellowsInterconnection Instrum.~20.5hose?DFBX~ 17.6hose?DFBX Pumping~20.5bellowsInterconnection~ 17.6hosesDFBX Filling (LD, C) ~20.5hosesDFBX~ 17.6hosesDFBX Cy~20.5Tube itselfDFBX~ 17.6Tube itself?DFBX CC’~20.5Tube itself?DFBX~ 17.6Tube itself?DFBX EE, FF~27.3hosesDFBX~23.5hosesDFBX

14. 14/18 Inner triplet review 24/4/07 C. Garion D1/DFBX, DFBX/Q3 interconnections Butt welds with persistent ring and backing gas Lip weld Filled weld Butt welds with persistent ring and backing gas

15. 15/18 Inner triplet review 24/4/07 C. Garion Jumper interconnections Standard Arc connections except manual lip welds Persistent ring Sleeve

16. 16/18 Inner triplet review 24/4/07 C. Garion Quality assurance  Procedures for all inner triplet interconnections provided by US collaboration.  All weld process have been qualified (CERN/SC, CERN/TS and IEG/APAVE) as well as welders.  Butt welds in the interconnections are done with backing inert gas.  X-rays are carried out on all butt welds and filled welds (where possible).

17. 17/18 Inner triplet review 24/4/07 C. Garion Interconnections Status PointLeftRight 1 Triplet connected except reparation of heat exchanger line (H) and few lines in the jumpers Triplet not yet available 2 Triplet aligned Interconnections in stand by 5 Triplet dismountedElectrical connections done and tested Interconnections in stand by 8 Triplet connected, isolated from the QRL, To be opened after warm up Triplet connected except reparation of heat exchanger line (H)  Great interest to find an in-situ reparation solution

18. 18/18 Inner triplet review 24/4/07 C. Garion Conclusions  Interconnection work is done according to the US procedures.  Weld process have been qualified. Welds are controlled with X-rays, where possible.  H pieces have been modified to increase stability of the cold mass lines and reliability of the heat exchanger inner copper tube.  H piece in Q2/Q3 has been validated during the pressure test in 5L up to 20 bars and with an elongation of 25mm.  Stability of interconnections could be improved to reach “standard” safety margin.