2. Summary of FCC Week – Magnets
April , Rome
B. Auchmann, TE-MPE TM, April 28, 2016

3. Overall Design, Collimation, Injection, Transfer, Dump
FCC Week – Program
Packed schedule (48 parallel and 6 plenary sessions + poster session + evening sessions + event & dinner)
470 Participants.
Tuesday
Wednesday
Thursday
Beam Dynamics
Overall Design, Collimation, Injection, Transfer, Dump
Conductor
Physics
Magnets RF
Experiments
A. Verweij
Cryo, Cooling, Safety
Technologies
Experiments
Physics
N.A. Tahir
Magnets
M. Prioli
A. Appollonio
A. Siemko
M. Prioli
A. Niemi

4. [G. F. Giudice, FCC and the Physics Landscape]
The HEP Challenge
What can the Higgs teach us?
What is beyond the Standard Model?
[G. F. Giudice, FCC and the Physics Landscape]

5. The FCC Design Study [M. Benedikt, FCC Study]
European Strategy for Particle Physics 2013:
“…to propose an ambitious post-LHC accelerator project….., CERN should undertake design studies for accelerator projects in a global context,…with emphasis on proton-proton and electron-positron high-energy frontier machines….coupled to a vigorous accelerator R&D programme, including high-field magnets and high-gradient accelerating structures,….”
US P5 recommendation 2014:
”….A very high-energy proton-proton collider is the most powerful tool for direct discovery of new particles and interactions under any scenario of physics results that can be acquired in the P5 time window….”
[M. Benedikt, FCC Study]

6. [F. Gianotti, CERN Roadmap and FCC]
Full exploitation of the LHC:
Run 2 started last year  goal this year is L=1034 at √s =13 TeV, ~25 fb-1
building upgrade of injectors (LIU), collider (HL-LHC) and detectors (Phase-1 and Phase-2)
Diversity programme serving a broad community:
ongoing experiments and facilities at Booster, PS, SPS and their upgrades (ELENA, HIE-ISOLDE)
participation in accelerator-based neutrino projects outside Europe (presently mainly LBNF in
the US) through the CERN Neutrino Platform
Preparation of CERN’s future:
vibrant accelerator R&D programme exploiting CERN’s strengths and uniqueness
(including superconducting high-field magnets, AWAKE, etc.)
design studies for future accelerators: CLIC, FCC (includes HE-LHC)
future opportunities for scientific diversity programme (new)
Important milestone: update of the European Strategy for Particle Physics (~ )
[F. Gianotti, CERN Roadmap and FCC]

7. FCC-hh Machine Layout
[M. Benedikt, FCC Study]

8. [J. Osborne, FCC Civil Engineering]

9. Superconductor Roadmap
[A. Ballarino, The FCC Conductor Development Plan]

10. CERN/EU 16 T Magnet Program
[G. de Rijk, On the road .. to 16 T and Beyond]

11. EuroCirCol – Design Constraints
Constraints for the magnet design
Bore inner diameter
50 mm
Beam distance
250 mm
Bore nominal field
16 T
Operating temperature
4.2 K
Operation on the load line
90 %
Maximum strand number per cable 40
Cable insulation thickness
0.15 mm
Cu/NCu ≥1
Field harmonics (geometric/saturation)
≤3/10 units
Peak temperature (105 % of operating current)
350 K
Yoke outer radius
400 mm
[V. Marinozzi et al., EuroCirCol Cosine Theta]

12. EuroCirCol – Design Options
Countless design iteration for all versions
Courtesy D. Schörling

13. EuroCirCol – Cosine Theta
[V. Marinozzi et al., EuroCirCol Cosine Theta]

14. EuroCirCol – Block Coil
[C. Lorin et al., EuroCirCol Block Coil]

15. EuroCirCol – Block Coil
[F. Toral et al., EuroCirCol Common Coils]

16. EuroCirCol – Magnetic Design
Cosine Theta
Block Coil
Common Coil
Inom [A]
10275
8470
9025
L/Ap [mH/m] 25 44 64
E/Ap [MJ/m]
1.5
1.7
2.6
Acond [cm2]
168
181
223

17. EuroCirCol – Mechanical Design
Coil stress not yet fully under control in Cos-theta design
Block coil already in good shape.
Block coil already in good shape.
Common coil features modest stress but ~ 1 mm
horizontal displacement

18. EuroCirCol – Magnet Protection
Initial peak-field and voltage-to-ground estimates by adiabatic analysis. Assumption: detection after 15 ms, all coil resistive after additional 40 ms. Bulk of coil heated up to room temp.! Low current density in inner-most turns together with min cu/nc ratio of 1 creates a > 100K temperature diff. in < 1 mm glass-fiber insulation.
[T. Salmi et al., Quench Protection]

19. EuroCirCol – Magnet Protection
Additional consequence of temperature gradient: large internal voltages due to bad inductive/ resistive compensation.
[T. Salmi et al., Quench Protection]

20. [D. Schörling, Cost Model]
Cost Model and Margins
(Very) preliminary cost estimates for 20% margin 16 T magnets vary between 5.4 and 11.7 GEUR for dipole magnets.
[D. Schörling, Cost Model]

21. Canted Cosine Theta High-field magnet program at LBNL.
L. Bottura: "Other lines consider ‘disruptive’ solutions (US-CCT, canted/collarless cos-theta) – very valuable !”
However, present 16-T design uses ~x2 more SC than cosine theta option, very high inductance and stored energy.
More R&D required.
[S. Caspi, CCT]

22. EuroCirCol – Powering Options
[A. Verweij, Circuit Protection]

23. Layouts with EuroCirCol Options
Cos-Theta
Block Coil
Common Coil
(High-Current Block Coil)
Block (LBNL)
Common Coil
[A. Verweij, Circuit Protection]

24. EuroCirCol – Powering Options
Study for block-coil option.
[M. Prioli et al., Circuit Powering]

25. EuroCirCol – Powering Options
Total power during FCC ramp.
Constant voltage
Pmax
Constant power
Pmax=160 MW
For a single circuit (L=54 H)
For the whole accelerator
Pmax=310MW
310 MW
14 MW
In addition: study if MB and MQ apertures could be powered in series;
study high-current switches, etc.
[M. Prioli et al., Circuit Powering]

26. Summary FCC CDR by the end of 2018.
Much work has been done on magnet design – no working solution yet.
Building a working 16-T magnet is the first challenge.
Making it cost-effective is the second challenge.
A long list of other topics have been discussed at the FCC Week:
physics potential
detectors and detector magnets
FCC-ee option (normal conducting magnets)
beam optics
collimation RF
cryogenics
ventilation
vacuum
safety
gender equality
relationship with industry
etc.