Hadron Collider Breakout Session Summary

D. Schulte, L. Bottura, B. Goddard,M. Jimenez

Programme

Pleas for Help and a Promise …

• Please help by

• signing up for the email lists• FCC-hh-design@cern.ch• FCC-hh-beamdynamics@cern.ch• FCC-hh-injectors@cern.ch• FCC-hh-technologies@cern.ch• FCC-hh-magnets@cern.ch

• reviewing and improving our parameters

• helping to prepare choices for the baseline design

• preparing the future collaboration

Conclusion

Will have video meetings

Will provide a list of critical issues

Actual work needed already now

Some Volunteers …

F. Petrov

A. Seryi

S. Chattopadhyay, Cocroft

Some Things to Address …

M. Jimenez

Technology Challenges and Breakthroughs

• Have a list with technical challenges that need to be addressed

• And breakthroughs that are required (will push technology in general)

• Very good place to find your favorite subject for the collaboration

M. Schaumann

First Look at the Ion performance

• Ion luminosity seems good using LHC injector chain

• Main luminosity limitations are from the injector chain

• Ions place a significant constraint on interaction region design

Magnets …

Breakout-magnets: summary

L. BotturaThoughts on a Friday night

Valentine’s day, 2014

Superconductors• Material research: the FCC superconductors are not looking like anything we

know from the past, nor HL-LHC. The present potential for improvement is in the range of 20 %... 50%, not enough– 5 years target: work on carrier density, pinning, grains to improve performance in

present high-field materials – 10 years target: consider other materials (Fe-based, MgB2, round REBCO)– Very large scale material requirements for LTS (10x ITER Nb3Sn production) and HTS

(much above anything done so far)

• Actions proposed:– Launch a focussed 16 T Nb3Sn conductor program (factor 2 Jc at 18 T)– Pursue work on HTS materials to make them suitable for accelerator magnets– Consider other issues (protection, filaments/field quality, homogeneity and yield for

low cost)– The LTHFSM Workshop could be an incubation center for material R&D

• Open questions:– Are exotic materials (Fe-based SC) a realistic candidate for R&D ?

Magnet technology• HL-LHC and companion HFM programs are exploring the

11...13 T operating field range, with ultimate field levels that are relevant to FCC (Fresca2), much experience can be drawn from these programs

• Is there a “barrier” at 15 T, or is this only perceived as such ?

• In the 16…20 T field range it is not clear what is the best geometry (block, cos-theta, CCT), examine them all

• The present design margin, in the range of interest, is very large (20 %) – how to decrease it ?

• Training, we cannot afford so many (> 10) quenches• Magnet protection is an issue both for LTS (energy density

vs. JE) and HTS (propagation speed and detection)

Matters of optima

• Tunnel length, operating field and temperature, SC material selection, are parameters affecting greatly the location of the optimum (minimum cost, maximum performance)

• Other constraints (e.g existing infrastructure), and benefits (e.g. the value of R&D at the field frontier) must be considered

My Comments on Magnets• Very interesting for a non-expert

– Much to be learned, thanks for the insight– Very active field

• Quite some interaction with other experts required for optimisation

• Should not forget the insertion magnets– Goal for b*=0.1m (Rogelio Tomas)– Challenges magnets– But helps for overall design

• Faster ramp of LHC magnets (O(3minutes)) appears possible– But some studies to be performed– Many issues of LHC re-use as injectors

• Need to evaluate aperture needs for injector in 100km ring

• Added some slides in the reserve on the different individual talks

In practice

• Define a direction for relevant R&D, set challenging (but realistic) targets, describe impact of this technology on other fields, and describe a development plan into a roadmap document to be contributed by the collaborators and edited within the scope of the FCC study

• This roadmap document will become a reference for future accelerator magnets R&D proposals (e.g. US-DOE, Horizon 2020), and can be used as a basis of collaboration for FCC design and hardware R&D work

• Time scale: 3 months (tough !)

• First volunteers• Also some private discussions with no presentation

• List of critical items to work on is progressing• Technical items shown by Miguel• Promised to produce first draft soon

• Very good discussion on magnets• Progress visible• Still new design ideas• Workplan in preparation

• Will continue with video meetings

Conclusion

Many thanks to the speakers and the chair Mike Syphers for almost keeping the schedule

And to all participants

The Summary that I Cannot Show

Some Key Points from the Talks

D.S., Brennan Goddard

MagnetsDavid Larbalestier: LTS and HTS Material Issues for 16 and 20 T Applications• Nb3Sn is still plan A• But have HTS cable, still issues to be addressed

Amalia Ballarino: Material R&D toward 16-20T horizon• ITER first large-scale user of Nb3Sn (800 A/mm2 at 12 T, 4.2

K): 500t• HL-LHC needs 2500 A/mm2 at 12 T, 4.2 K• FCC with 16 T magnets: 4,500 tons of Nb3Sn and 10,000

tons on NbTi• FCC with 20 T: 1,400 tons HTS, 6,300 tons Nb3Sn, 11,000

tons NbTi

MagnetsPaolo Ferracin: Overview of HiLumi low beta and FRESCA2 magnets• FRESCAII is block magnet to test HTS inserts• Forces and stresses on coil for FRESCA2 comparable to 16-

20 T coils

Mikko Karpinnen: 11T Experience• Many lessons learned from the 11T work for the HL upgrade

Steve Gourlay: SC Magnet Developments Towards 16T Nb3SN Dipoles• A slanted solenoid design looks attractive and should be

tested

MagnetsEzio Tedesco: Design Options for the 15-20T Range• We should review the design margin, it cost a lot

Peter McIntyre: Low Cost Magnet Design• We should think about the cost not focus only on the field

Attilio Milanese: Injector Magnet Considerations• The LHC magnets can be made to ramp up in 3 minutes,

with some sissues to be addressed

Rogelio Tomas: Insertion Magnet Challenges• Insertion magnets are also important• Should aim for b=0.1m

David Larbalestier: LTS and HTS Material Issues for 16 and 20 T Applications

16 T for 100 TeV in 100 km

16 T magnet in 100 km tunnel Width

(mm)Average

radius (mm)Overall Jc (A/mm2)

Strand Jc (eng) (A/mm2)

Conductor mass (t)

Nb3Sn layer 1 20 30 193 386 1690

Nb3Sn layer 2 20 50 385 770 2710

20 mm collar

Nb-Ti layer 1 15 87.5 337 523 4710

Nb-Ti layer 2 15 102.5 433 672 5520

4300 tons Nb3Sn + 10200 tons of Nb-Ti

Cosine theta type magnet, Nb-Ti and Nb3Sn. Bore = 40 mm

9 times Nb3Sn for ITER and Nb-Ti for LHC

A. Ballarino, CERN

Material R&D toward 16-20T horizon

• ITER will be first large-scale (500t) user of Nb3Sn, with 800 A/mm2 at 12 T, 4.2 K

• HL-LHC needs 2500 A/mm2 at 12 T, 4.2 K

• Total amount of conductor needed for 16 T magnets in 100 km collider would be about 4,500 tons of Nb3Sn and 10,000 tons on NbTi

• For 20 T in 80 km tunnel, 1,400 tons HTS, 6,300 tons Nb3Sn, 11,000 tons NbTi

• Production quantity of HTS is huge by today's standards - too early to even start guessing about cost

Amalia Ballarino

Paolo Ferracin

Overview of HiLumi low beta and FRESCA2 magnets

• Low-beta is 7 m long magnet, accelerator quality coils and magnet at 12 T operational field level, Nb3Sn, cos2theta

• FRESCA2 is aiming at 15 T dipole field for HTS insert tests, not accelerator quality, block coils

• Forces and stresses on coil for FRESCA2 comparable to 16-20 T coils

Mikko Karpinnen

11T Experience

• Many lessons learned from the 11T work for the HL upgrade• Cannot list them here

• Useful input for future R&D

The Canted Cosine-Theta (CCT) Magnet

Superconducting Magnet Group - S.Caspi

“perfect” current distribution

Steve Gourlay

SC Magnet Developments Towards 16T Nb3SN Dipoles

• Different winding scheme potentially could make magnets cheaper by reducing stress

• Paradigm change?

• This seems well worth exploring

Ezio Tedesco

Design Options for the 15-20T Range

• Need to review required margin

Low Cost Magnet Design

• Should consider an overall cost optimisation leaving the dipole field as a free parameter

• 5 T 10 K dipole is excellent candidate for rapid-cycling injector

Peter McIntyre

Attilio Milanese

Injector Magnet Considerations

• Different options of injector magnets investigated

• SPS with Nb3Sn magnets takes 5-10 minutes to ramp, require 25 ramps

• LHC magnets can likely ramp faster than now with some modifications in the power supplies (2-3 minutes)

• Option with normal magnets in the 100km ring need to be reviewed for impedance and required aperture

R. Tomas

Insertion Magnet Challenges

• The interaction region contains challenging magnets

• They can drive the system design

• The interaction region impacts the overall design strongly(the beta-function determines the required beam current)

• Should aim for beta-function of 0.1m

• High field magnet development essential even if cost is high