# Presentation: 283552

- LHC IRQ Cryostat Production Readiness ReviewJanuary 23, 2002T. Nicol – Fermilab_tnicol@fnal.gov__http://tdserver1.fnal.gov/nicol/index.html_

## When last we met...

## First prototype (Q2P1)

## Outline

- EDR action item review.
- Design evolution since EDR.
- Buswork and instrumentation.
- Parts status.
- Tooling overview (tour).
- Outstanding issues.
- Q1 design concepts.

## PRR-related cryostat EDR action items (numbers from original report)

***3.******	******Use of automatic welding equipment (BOTH – TP)***
- _Action_:	Fermilab is evaluating eliminating the beam pipe – cold mass differential expansion bellows which would increase the radial clearance in that area.
- _Action_:	Fermilab needs to identify all welds that will fall below the requested clearances of 45 mm radial and 130 mm axial.
- _Action_:	CERN and Fermilab need jointly to address viable solutions to any space-restricted welds.
***4.******	******Interface between cryostat feet and jacks (PRR – TN)***
- _Action_:	Fermilab needs to provide the details of the interface between the cryostat feet and jacks.
***6.******	******Shipping loads (PRR – TP)***
- _Action_:	Fermilab needs to include shipping restraints that are capable of isolating the cryoassembly from anticipated shipping loads.  The resulting loads on the cold mass support need to be kept below 2 g.

## PRR-related cryostat EDR action items (cont’d)

***8.******	******Cold bore temperature in the magnets (PRR – TN)***
- _Action_:	CERN needs to determine if an actively cooled beam screen is required in Q1.
- _Action_:	If an actively cooled beam screen is required, Fermilab needs to add piping to supply an actively cooled beam screen in Q1, and LBNL needs to determine if this affects the DFBX design.
***10.******	******Drawings (PRR – TN)***
- _Action_:	Fermilab needs to submit drawings that are critical to support design integration with CERN.
***11.******	******Transportation, lifting and handling (PRR – TN and TP)***
- _Action_:	Fermilab needs to prepare the tunnel interface specification.  The specification should include transportation and handling criteria and limitations applicable on the surface, down the access shaft, to the transport vehicle, and to the installation location.
- _Action_:	Fermilab is requested to perform a simple dynamic response study of the quadrupole cryoassembly.
- _Action_:	Fermilab will transport Q2P1 around their site and take measurements to obtain some data on the mechanical stability of the cold mass.
- _Action_:	CERN needs to arrange for necessary lifting and handling tools to be used at the LHC.
- _Action_:	CERN needs to develop the full installation scenario for the quadrupoles, from receipt at CERN to final installation in the LHC.

## PRR-related cryostat EDR action items (cont’d)

***12.******	******IP end of Q1 (BOTH – TN)***
- _Action_:	Fermilab is requested to propose a “shortest possible” IP end of the Q1 cryoassembly on the assumption that the BPM is located outside of the vacuum vessel.
- _Action_:	CERN needs to provide designs for the warm-to-cold transition, including stay-clear areas to Fermilab.
***13.******	******Stability of thermal shields (PRR – TN)***
- _Action_:	Fermilab is requested to analyze the resistance of the thermal shield to buckling due to pressure in the extrusion piping and collapse due to eddy currents during quench.
***14.******	******Cold mass support (PRR – TN)***
- _Action_:	Fermilab is requested to review the test data to determine the onset of failure.
***15.******	******Alignment tolerances and aperture reductions (PRR – TN)***
- _Action_:	Fermilab is requested to establish a positional tolerance for the beam tube and confirm that the stack-up of tolerances is within the capability and reliability of the bellows.
- _Action_:	Fermilab is requested to evaluate the effect of the sag of the cold mass and cantilevered beam tube, and to work with the CERN Apertures Working Group to determine the effect on the aperture.
- _Action_:	CERN needs to confirm the allowable offsets for beam vacuum bellows.
- _Action_:	Fermilab needs to verify the weld interface between the cold bore and cold mass does not result in an aperture reduction.

## PRR-related cryostat EDR action items (cont’d)

***16.******	******Radiation effects (PRR – TN)***
- _Action_:	Fermilab and CERN need to determine if radiation degradation testing needs to be performed on the sliding material.
- _Action_:	Fermilab is requested to estimate the contact doses for the inner triplet, particularly in the interconnects.
***17.******	******Electron cloud effects (PRR – TN)***
- _Action_:	Subsequent to the review, Fermilab verified that electron cloud effects are included in the heat load table.
***19.******	******Cleanliness of the cold bore (PRR – TN)***
- _Action_:	Fermilab plans to keep the cold bore closed after cleaning.
***20.******	******Trapped volumes (PRR – TN)***
- _Action_:	Fermilab intends to confirm that no trapped volumes are present in the design.
***21.******	******Alignment of correctors (PRR – JK and TP)***
- _Action_:	Fermilab is requested to evaluate the design of the corrector mounting against the alignment requirements.  Fermilab intends to submit a corrector interface specification and the method for alignment should be documented in detail in the specification.

## PRR-related cryostat EDR action items (cont’d)

***22.******	******Load simulation heaters (PRR – ML)***
- _Action_:	Fermilab needs to determine the size and configuration of the load simulation heaters with CERN.
***23.******	******Helium inventory (PRR – TN)***
- _Action_:	Fermilab is requested to specify the volume distribution of helium throughout the triplet.

## Progress since EDR (March 2001)

- Testing of Q2P1 complete, including heat load estimate.
- Tooling design and fabrication complete.
- Modifications to design based on Q2P1 experience complete.
- Design, drafting, and all parts ordering for Q2 complete.
- Some Q1 and Q3 parts design complete and on order.
- Good progress working with CERN vacuum and BPM groups on cold bore termination, cold-to-warm transition design, and BPM connections.
- Slide material irradiated, but not retested (appears undamaged).
- Specifications and interface documentation in-process.
- Preliminary shipping test complete.
- KEK engineering note received.

## Engineering note approvals on Q2P1

## KEK engineering note cover and table of contents

## Design changes based on Q2P1 experience

- Check through-hole dimensions of end flanges and modify end design to accommodate positive tube stop.
- Reduce clearance in the through-holes in the pipe supports to ensure better alignment at the interconnect.  Might think about adding a G-10 insert for insulation and spacing.
- Add a support/locator for the shield extrusions at the outermost pipe supports.  Tie it into the holes used for the tie-bar collars.
- Change the RIVNUT fasteners in the support rings and shield center rings to PEM nuts like those used on the bellows restraints.  (Increase the OD of the support to accommodate the reduced height of the fastener heads.)
- Put threaded inserts in the shield extrusions.
- Add a full-length rail through the vacuum vessel as guides for the rollers.
- Radius any potential sharp edges on the rollers.
- Specify the epoxy bond better between the support G-11 and the attachment lugs.

## Design changes based on Q2P1 experience (cont’d)

-  Change shield fasteners to flat-head.
- Fix the azimuthal location of the MLI blanket seams and add cutouts to drawings for the cold mass support rods, pipe supports, and support attachment lugs.
- Revise the shimming scheme between the cold mass attachment lugs and the cold mass to show shims between the lugs and rods, not between the cold mass and lugs.
- Add clearance slots in pipe supports for threaded rods connected to support rollers.
- Redesign attachment bolts and threaded inserts so we can turn the 52 mm insert without removing the tie-down bolt.
- Change the 52 mm insert to fine thread.
- Design a special 52 mm threaded insert to accept a hydraulic cylinder.
- Check vacuum vessel sliding and fixed flanges to ensure compatibility with CERN bellows.

## Buswork and instrumentation...

## Parts on order

- Parts for all Q2 complete magnets are on order.
- Parts on order for all magnets (i.e. Q1, Q2, and Q3) include the following:
- Vacuum vessels.
- Supports.
- Pipe supports.
- Heat exchanger corrugated tube.
- Heat exchanger supports and flow restrictors.
- Cold mass bellows.
- Cold mass extensions and end domes.
- Of approximately $2.4M in M&S, a little over $1M remains to be committed.

## Q2 vacuum vessel

## Q2 vacuum vessel flanges

## Parts expected from CERN

- Beam tubes.
- Correctors.
- Corrector and instrumentation wire.
- Strip heaters and RTDs.
- Interconnect vacuum bellows.
- Fiducial holders.

## Q2 complete magnet

## Cryostat assembly area in ICB

## Cold mass completion tooling

## End of part 1...

## Cold bore vacuum interconnects

- Q3 end

- Q1 to Q2 int

- Q2 to Q3 int

- Q1 end

## Absorbers

- TAS B

- TAS A

## Shipping...

## Shipping...

## Concerns

- Delivery concerns for a few critical parts, e.g. vacuum vessels, tie-bars, and beam tubes.
- Tooling appears complete, but is untested.
- Shipping details remain unclear.
- Absorber interface is closely coupled to cold bore vacuum components being developed at CERN.
- Expansion loop performance and support.