# Presentation: 610305

## LHC Inner Triplet Status

- J . Kerby
*For...Ranko Ostojic, Cedric Garion, Tom Page, Thierry Renaglia, Herve Prin, Bob Wands, Frederic Gicquel, Ingrid Fang, Juan Carlos Perez, Tom Nicol, Sandor Feher, Tatsu Nakamoto, Peter Limon, Joseph Rasson, Steve Virostek, Paul Olderr, Tom Peterson, Jim Strait, Jim Rife, Vadim Kashikin...and anyone else I have inadvertently forgotten...*

## Review of 27 March sector 7-8 pressure test
Requirements for the fix
Cartridge for Q1 / Q3

Vacuum Loading
DFBX
Schedule

- Requirements for the fix
- Cartridge for Q1 / Q3
- Vacuum Loading
- DFBX
- Schedule

- 14 June 2007

## Slide 3

- 14 June 2007

## Non IP end of Q1, looking toward IP

The Xb, XBt, V EE and FF lines, and beam screen lines were not pressurized during the 27 Mar test

- The Xb, XBt, V EE and FF lines, and beam screen lines were not pressurized during the 27 Mar test

- 14 June 2007

## Tables for the full load case when all lines are    pressurized to MAWP
27 March test the pumping and shield lines were not pressurized, and failure was at 20 bar
Q1 load 115kN
Q3 load 93kN

- 27 March test the pumping and shield lines were not pressurized, and failure was at 20 bar
- Q1 load 115kN
- Q3 load 93kN

- 14 June 2007

- Q1
- 115kN

- Q3
- 94kN

- 14 June 2007

## Cold Mass Support

- A ‘fixed’ and ‘free’ spider support
- Invar rod connecting the two to share support

- 14 June 2007

## Geometry was drawn directly from the CAD model. The bellows at the interconnections between cold masses were simulated with spring elements having a total stiffness of 5500 lbs/in at each interconnection.

- Moments due to the L line bellows were estimated, and are reacted w/ much longer lever arm of the spacing of the supports, so are a small effect in these analyses.
- Elements are second-order hexahedral and tetrahedral solids. A total of 500 thousand elements and 600000 nodes were used.

- 14 June 2007

## Meshing of the supports was refined to include three elements through the half-inch thickness of the G11.

- The G11 was treated as orthotropic; in the plane of the support (the xy plane in the analysis) bending is resisted primarily by the tension or compression of the relatively stiff glass fibers; the Young's modulus is dominated by the glass, and was set to 3e6 psi in both the x and y directions. For the z-direction (through the thickness), loads are perpendicular to the glass fibers, and the stiffness is influenced more strongly by the epoxy matrix; a reduced modulus of 1e6 psi was used for this direction. Note that while this is technically "orthotropic", it really assumes isotropy in the xy plane.

- 14 June 2007

## Q1- Q2 - full 20 bar load (all lines)

- 14 June 2007

## Q3 – full 20 bar load (all lines)

- 14 June 2007

## Pressure Test Summary

- With Shield and Xb lines empty, actual loads 84% of 20 bar load in model...results linearly scaled for now:
- Q1 fixed support failed at 16,950lbs/75.4kN (7.5mm); then propagated to Q1 free support
- Q3 fixed support being checked at 14250lbs/63.3kN (6.4mm); Q3 free support shows no signs of damage
- Q2 unaffected
- DFBX damage not from interaction with Q3

- 14 June 2007

## Requirements for a Fix

- In Situ
- Does not move fixed point of the assemblies
- React loads with sufficient stiffness to limit deflection – ~140kN design load (slide 4)
- Acts at any temperature 300K to 2K
- Focus on implementation in Q1—Q3 solution identical in length, IP end

- 14 June 2007

## Fixed Points

**MQXA**

**MQXB**

**MQXA**

**MQXB**

**Q3**

**Q2A**

**Q1**

**DFBX**

**Q2B**

**38490**

**MQXB**

**LBX**

**D1**

- External heat exchanger (HX)

- Fixed Point HX-Cold Mass

- FP Cold Mass-Vacuum Vessel

- Fixed Point Triplet-Tunnel Floor

- Tie Rods Linking Vacuum Vessels

- Jacks (longitudinal)

- Internal heat exchanger

- 14 June 2007

## Slide 15

- 14 June 2007

## Slide 16

- 14 June 2007

## Q1

- 14 June 2007

## Q1

- MQXA

- Corrector
- Containment

- 14 June 2007

## Q3

- 14 June 2007

## Q3

- MQXA

- Corrector
- Containment

- 14 June 2007

## Slide 21

- 14 June 2007

## Allowable Deflection of Support

- From failure analysis support fails at deflection of 7.5mm (6.4mm borderline)
- System Analysis from Q1-Q2-Q3
- Cooldown deflection ~1.0mm in Q2 free spiders (all tested, ok)
- Analysis of test in fixture, test results, suggest 2.8mm

- 14 June 2007

## Cooldown / 20 bar loads – Q1/Q2

- 137kN
- (0kN)

- 35kN
- (27kN)

- 77kN
- (-13kN)

- 25kN
- (-14kN)

- 35kN
- (27kN)

- 10kN
- (10kN)

- 0kN
- (0kN)

- 35kN
- (27kN)

- 10kN
- (10kN)

- 14 June 2007

## Cooldown / 20 bar loads – Q3

- Contraction of cold mass interconnect bellows Q1-Q2 and Q2-Q3 reacts portion of quench load
- Further models move from full triplet to Q1 only w/ load of interconnect bellows included
- W/ cooldown, free support pulled toward fixed support by Invar tie rod

- 35kN
- (27kN)

- 62kN
- (-13kN)

- 18kN
- (-14kN)

- 115kN
- (0kN)

- 14 June 2007

## Allowable Deflection of Support

- Testing / modeling to failure of individual supports
- The cold mass provides a rotational constraint on the support and lug which does not exist in the test fixture
- Test of single spider in fixture failed at 6900lbs, 17mm deflection
- Modeling used to translate results to spider / invar system, including gravity loads.
- 2.8mm bending of spider in installed configuration OK including safety factors
- Removing front split ring on fixed support adds another 17.5mm of allowable motion

- 14 June 2007

## Removing the front split ring is important as the cartridge is a much stronger spring than the support and would pull the cold mass 5.5mm if a large thermal mismatch existed
Addition of 17.5mm of travel by removing this split ring, and using the cartridge to set the fix point of the assembly, greatly simplifies failure mode analysis.

- Removing the front split ring is important as the cartridge is a much stronger spring than the support and would pull the cold mass 5.5mm if a large thermal mismatch existed
- Addition of 17.5mm of travel by removing this split ring, and using the cartridge to set the fix point of the assembly, greatly simplifies failure mode analysis.

- 14 June 2007

## Cartouche / Cartridge

- Affixed at Q1 non-IP end; Q3 IP end
- Transfer load at all temperatures
- Limits support deflections

- 14 June 2007

## Slide 28

- 14 June 2007

## Slide 29

- 14 June 2007

## Q1 Cartridge Modeling

- Cartridge applied to Q1 model including bellows for:
- Warm 25 bar pressure test load
- Cold
- Cold, 20 bar quench load

- 14 June 2007

## Q1 Cartridge, 25 bar pressure test

- 171kN

- 8kN

- 18kN

- 144kN

- 2kN

- 14 June 2007

## Q1 Cartridge, Cooldown

- 0kN

- 13kN

- 9kN

- 5kN

- 27kN

- 14 June 2007

## Q1 Cartridge, cooldown + 20 bar

- 137kN

- 6kN

- 5kN

- 109kN

- 28kN

- 14 June 2007

## Q1 Cartridge, Deflections

- Load per cartridge:  36kN (warm test, 25 bar evenly split)
- Al tube stress (3300 psi / 8600 psi ASME allowable) (22.7MPa/59MPa allowable)
- Invar peak cross section (16600 psi / 21600 psi) (114MPa / 148MPa) (Allowable – 3 to ultimate or 2 to yield of annealed Invar)

- 14 June 2007

## Thermal Analysis

- 14 June 2007

## Invar rod temperature

- 14 June 2007

## Vacuum vessel flange temperature

- 14 June 2007

## Cartridge Summary

- _Cartridge design in production and testing_
- Worst case Q1 spider support longitudinal deflection < 2mm limit
- Worst case Q1 spider load < 1⁄4 load that caused failure during recent pressure test
- Does not move magnet fix point
- In fact fixes Q1 / Q3 better than currently
- Magnetic effect negligible
- Additional load to 2K of a few Watts; Vacuum Oring OK.
- Mechanical tests have been done on:
- Removal of split ring at fixed point
- Invar / Al tube connection
- Vacuum bracket to flange weld
- Full standalone cartridges
- Test of 4 cartridges installed on a Q1 in process, actual test next week
- Successful removal of split ring covers upset conditions
- Covers failure modes in thermalization of cartridge / cold mass
- On track for sector 8-1....

- 14 June 2007

## Q1

- 14 June 2007

## Q1

- 14 June 2007

## Vacuum Loads to Ground

- 14 June 2007

## Vacuum vessel to ground

- Apr 24-25 Review noted issues to be resolved w/ alignment / jacks / tunnel ground under triplets
- Safety factor of vacuum tie bars between vacuum vessels and DFBX also questioned

- 14 June 2007

## 25 bar load + Vacuum load (+bellows); no transverse load on jacks

- 25 bar load + Vacuum load (+bellows); no transverse load on jacks

- Vacuum Vessel Deflections
- V1 4.3mm to IP
- V2 2.0mm to IP
- V3 0.4mm from IP
- Vac Bellows makes ~5% change in deflections in 2 previous cases

- 100kN

- 171kN

- 100kN

- 1kN

- 2kN

- 100kN

- 2kN

- 2kN

- 2kN

- 100kN

- 135kN

- 32kN

- 14 June 2007

## Slide 44

- 14 June 2007

## Vacuum Tie Bar Ass’y

- Outer nut omitted to prevent excessive load in the event of a cryogen spill inside the vacuum vessel

- 14 June 2007

## Connection Details

- Nut to tighten sleeve against intermediate ear

- Nut to tighten assembly against vacuum vessel ear

- Spherical washers

- 2” OD, 1.25” ID sleeve

- Tie rod

**Tie rod, nuts, and spherical washers are the same as those in the current system**

- 14 June 2007

## Connections Details (2)

- 14 June 2007

## DFBX

- 14 June 2007

## DFBX-E 

**DFBX-E **
**17 Feb 05**

- 14 June 2007

## Bus Duct Assembly: Thrust Load

**Q3:  20 KN**

**LD:  6.5 KN**

**D1:  10.1 KN**

**Bus Duct Assembly: Thrust Load**

**Thrust Support Brackets**

- 14 June 2007

## MQX1

- 4 screws on each side

- Swivel support

- Fully adjustable support

- Feature allowing to loosen up the tolerances on the bore

- 14 June 2007

## MBX1

- Cut to loosen up the tolerances

- Handles to ease installation

- Cut to allow  a full adjustment from the back with custom made tooling

- Fully adjustable leveling mount

- 14 June 2007

## Summary

- Production and Qualification tests of solutions in process
- Materials and parts arriving at CERN
- Initial hydraulic test in 181 next week on Q1
- DFBX solution design complete
- On track for sector 8-1 and repairs in remaining sectors
- Great effort across labs

- 14 June 2007

## Slide 54

- 14 June 2007

## 8-1

- 1-2

- 4-5

- 7-8

- 6-7

- 5-6

- 3-4

- 2-3

- 14 June 2007