1. Hadron Collider Breakout Session Summary
D. Schulte, L. Bottura, B. Goddard,
M. Jimenez

2. Programme

3. Pleas for Help and a Promise …

4. Conclusion Please help by signing up for the email lists
reviewing and improving our parameters
helping to prepare choices for the baseline design
preparing the future collaboration
Will have video meetings
Will provide a list of critical issues
Actual work needed already now

5. Some Volunteers …

6. F. Petrov

7. A. Seryi

8. S. Chattopadhyay, Cocroft

9. Some Things to Address …

10. 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

11. 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

12. Magnets …

13. Breakout-magnets: summary
L. Bottura
Thoughts on a Friday night
Valentine’s day, 2014

14. 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 ?

15. Magnet technology
HL-LHC and companion HFM programs are exploring the 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)

16. 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

17. 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

18. 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 !)

19. Conclusion 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
Many thanks to the speakers and the chair Mike Syphers for almost keeping the schedule
And to all participants

20. The Summary that I Cannot Show

21. Some Key Points from the Talks
D.S., Brennan Goddard

22. Magnets
David 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

23. Magnets
Paolo 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 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

24. Magnets Ezio 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

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

26. 16 T for 100 TeV in 100 km 4300 tons Nb3Sn + 10200 tons of Nb-Ti
Amalia Ballarino
Cosine theta type magnet, Nb-Ti and Nb3Sn. Bore  = 40 mm
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
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 50
385
770
2710
20 mm collar
Nb-Ti layer 1 15
87.5
337
523
4710
Nb-Ti layer 2
102.5
433
672
5520
More than 8 time the quantity of Nb3Sn for ITER and of Nb-Ti for LHC
4300 tons Nb3Sn tons of Nb-Ti
9 times Nb3Sn for ITER and Nb-Ti for LHC
A. Ballarino, CERN

27. 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 T coils

28. 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

29. The Canted Cosine-Theta (CCT) Magnet
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
“perfect” current distribution
Superconducting Magnet Group - S.Caspi

30. Design Options for the 15-20T Range
Need to review required margin
Ezio Tedesco

31. Peter McIntyre
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

32. 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
Attilio Milanese

33. 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