eucard-wp7-hfm collaboration meeting 24/04/2012 warsaw

EuCARD-WP7-HFM Collaboration Meeting

24/04/2012Warsaw

Task 3 : High Field Magnet

Sébastien Clément, Melanie Devaux, Maria Durante, Philippe Fazilleau, Paolo Ferracin, Elvis Fornaciere, Jorge Enrique Munoz Garcia, Rémy Gauthier, Jean-Jacques Goc, Pierre Manil, Attilio Milanese, Jean-Francois Millot, Juan- Carlos Perez, Alain Przybylski, Jean-Michel Rifflet, Gijs de Rijk, Francoise Rondeaux, …..

Outline

– Dipole review : March 28-29 2012 : reviewers recommendations– Brief Status–Global planning– Conclusions

24/04/2012 2CEA/DSM/Irfu/SACM – J.M. Rifflet - EuCARD HFM - Task 3 : High Field Magnet

ESAC Review March 28-29 2012

External Scientific Advisory Committee:- Giorgio Ambrosio (Fermilab) (Chair)- Shlomo Caspi (LBNL)- Pasquale Fabbricatore (INFN Genova)- Arup Ghosh (BNL)- Yukikazu Iwasa (MIT)- Tatsushi Nakamoto (KEK)- Lucio Rossi (CERN)

Charge of review:1. Is the magnet construction process sufficiently studied to start coil

construction ? 2. Is the conductor technically ready for this magnet ?

3. Are there risks which have not been covered ?

4. Is the quench protection for the dipole sufficient ?

5. Is the schedule credible ?


General remarks

•Significant progress since last review …•The team is now aware of the challenge (RMC) • Change in task deliverable ( single coil tested in the Fresca2 structure) much more realistic.

focus on the analysis of the single coil testAdd a RMC test results review Wait for 1st coil test results before starting the

fabrication of other coils •Too many discussions during the meeting More internal or inter-lab discussions.

•A few minor inconsistencies among the presentations (pole material, test planning)


1. Is the magnet construction process sufficiently studied to start coil construction ?

• Mechanic analysis now takes fabrication process into account.

• Contraction of coil (winding tension and effect of heat treatment on Nb3Sn) stress and strain in coil. A clear analysis must be done. Already started (tooling delivered)

• Analyze in detail the case of just one Nb3Sn coils test in structure . Just started (see Paolo’s talk)

• Wait for this test results before winding the 3 other coils . To be discussed…


1. Is the magnet construction process sufficiently studied to start coil construction ?

• RMC program will confirm cable quality . If possible wait for RMC test results before the winding of first coil

• Impregnation between two double pancakes is a good point , but it could be a difficult and critical operation (risk of large voids inside). Maybe some test could be done using the copper dummy coils


2. Is the conductor technically ready for this magnet ?

•Reviewers understood that cable thickness is fixed at 1.86 mm. In our mind, it is not frozen adjustable tooling, but should be fixed asap

•From the standpoint of magnet operation at 13 T, cabling degradation as high as 20 % could be tolerated, however ,

•Cause of degradation needs further investigation. (filament distortion ? Look at n-value) – Question: for the same cable parameters would

wires from different billets behave similarly ?•Consider fabricating the cable for the RMC coil asap and check its degradation using extracted wires.

•PIT strand availability is sufficient for the 4 coils. Consider acquiring additional strand for a 5th spare coil.



•A lot of progress has been made since the last review and many of the potential risks have now been, at least partially addressed.

•The Fresca target has been redefined : – Build the RMC magnet to test racetrack Nb3SN

cables, layer jump, leads ….– The Fresca2 deliverable is now a test of a single

flared end coil in the structureDeclare success and do not proceed in making the

rest of the coils, before results have been analyzed and reviewed



•We still need to quantify the role of the inner coil support .

•The interaction between the inner layer pole and the outer layer island should be covered



•RMC is good for cable verification, but testing two double layers may be needed to go above 93%.

•Coated parts for electrical insulation : good. Additional R&D work may be required

• The analysis of conductor strain due to heat treatment and cooldown appears to be incomplete. FEM analysis of strain in the coil during and after cooldown

depending on pole material All tooling and the coil fabrication procedures should be

designed/engineered in order to accommodate longitudinal gaps in case the experimental tests will show that they are needed. Discussions started


4. Is the quench protection for the dipole sufficient ?

•Yes. A detect-and-dump active protection technique adopted is appropriate

• Is a thermal delay of 50 ms reasonable? Introduce thermal contact resistances

•A heater power density of 50 W/cm^2 seems to be a little high (lead to ~50 A in 304L heaters 25-μm thick). 25 W/cm^2 probably better.

•Hot spot temperature analysis appropriate. •The assumption of a 100-ms delay for triggering this active protection technique is reasonable.

•We should remember that an active protection technique itself is susceptible to its own malfunctions.



•EuCARDdeliverables, “Test structure with 1 SC double pancake by April 2013”, appears to be very challenging.

•The obvious show-stopper is the testing cryostat where the first cold test can be anticipated only at October 2013 or later. The committee strongly suggests the team to speed up the preparation of the testing cryostat so that the first test can be made by April 2013.

•Explore the possibility of testing Fresca2 in a simple horizontal cryostat, even at 4.2 K only; while its final vertical cryostat and facility are prepared (which may happen in more than 1.5 year from now according to some reviewers).



•Accelerate the cable study to understand the performance and finalize the cable parameters for both PIT and RRP conductors as soon as possible.

•RMC development is a essential way to evaluate the cable performance as well as some design features (such as layer jump) . Be careful with resources

loads •Provide the concise project schedule that will cover all important milestones including the RMC development and clarify the deadlines and target dates.


My comments

•Reviewers often ask for results before to go to next steps. This is not always compatible with particular plannings (EuCARD, French contribution, CERN strategy, …). We have to evaluate risks and sometime proceed without results.

• FRECA2 is part of CERN strategy, as well as RMC program. This strategy should be shared with other partner (via larger collaborations for instance)

•Reviewer comments show that we are on the good way , but we must remain vigilant


HFM Task 3 Brief status• HHM magnet :Still some points to clarify, but global design

ready• Tests :

– Ten stack measurements : to be done– Cable behavior during heat treatment: tooling delivered, Pit

cable available, tests to be done– Dishing : to be checked during copper coil winding

• Winding tooling : some part delivered. Available end of May. Copper winding of 1st coil 3-4 in July

• Reaction tooling : almost ready for call for tender• Impregnation tooling : defined, study to be done• Structure: in fabrication; aluminum shell delivered

• Interaction with Insert : Protection to be studied


24/04/2012 16

Global Planning

CEA/DSM/Irfu/SACM – J.M. Rifflet - EuCARD HFM - Task 3 : High Field Magnet

EuCARD 7.3Specifications, magnet preliminary design Fresca 2 Nb3Sn Dipole designCoils component and tooling detailed studiesCoil component and tooling procurementAssembly structure procurement and testConducteur procurement QUALIFICATION PILOT PRODUCTION

Cabling and characterization1st Cu coil manufacturing Cu 12nd Cu coil manufacturing Cu 13rd Cu coil manufacturing Cu 31st Nb3Sn Coil manufacturing C11st Coil tests (with 3 Cu coils) C12nd Nb3Sn Coil manufacturing C23rd Nb3Sn Coil manufacturing C34th Nb3Sn Coil manufacturing C4Dipole assembly M1Dipole tests M1

Design studies, CAO (CEA and CERN)CEA and CERN realisationProcurementsat CERNEuCARD Milestone or DeliverableCEF Milestone or Deliverable

39 42 45 4821 24 27 30M0 3 6 9 12 15 18 33 36

T2 T3 T4T4 T1 T2 T3 T4 T12013

T1 T2 T3 T4 T1 T32009 2010 2011 2012

T2 T3 T4 T1 T22014

T1 T2 T3 T4ble

24/04/2012 17

Conclusions

•Some critical issues are still not fully covered . Among them, the behaviour of Nb3Sn cable during and after reaction treatment (this could impact the winding and reaction tooling)

•. Tests made with PIT cable must be repeated wit RRP cable

•Winding will start in July with copper conductor

•The EuCARD deliverable is not in time : Fabrication of coils, assembly of structure and test facility preparation are critical

•A lot of work has been done, but …

a lot of work is still to be done

CEA/DSM/Irfu/SACM – J.M. Rifflet - EuCARD HFM - Task 3 : High Field Magnet

eucard-wp7-hfm collaboration meeting 24/04/2012 warsaw

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