1. Plans for the PSI Canted-Dipole Program
Bernhard Auchmann, CERN/PSI, Gabriella Rolando, PSI/CERN Shlomo Caspi, LBNL
March 28, 2017

2. PSI Goals towards FCC Requirements
Thin spars
Exterior Bladder and Key structure
Impregnation system (NHMFL resin, etc.).
Fast quench detection and CLIQ protection.
Wide Rutherford cable.
Inclined channels manufacturing.
Former manufacturability and cost reduction (with Fraunhofer/industry).
PSI program to be complementary to US MDP program.
CD1
CD2

3. CD1 and CD2 Cable and Geom. Params.
PSI builds one mechanical structure for
CD1:
LBNL CCT cable (0.85 mm diam, RRP 108/127, 21 strand),
10.6 mm channel depth, 3 mm spar, 0.5 mm assembly gap
Layer-2 OD = 122 mm, ID = 65.6 mm (clear bore).
CD2:
15-T IL cable, (1 mm diam, RRP 150/169, 28 strand)
16 mm inclined channel, Layer-2 OD = 122 mm, ID = 48 mm (clear bore).
CD1 introduces CCT technology to PSI.
CD2 fits into MDP 15-T outer layers 3&4.

4. Mechanical Structure
Bladder and Key technology chosen for tunability and relative simplicity.
Closed pad gap
Bladder locations
25 mm Al shell
Vertical and horizontal keys
Protective Al shell
Vertically split yoke, OR 250 mm
Vertically split pad, min thickness 30 mm
Steel or iron?
Al-bronze former
Open yoke gap

5. CD1 Magnetic Design ISS = 20 kA at 4.2 K (~11 T bore field).
For iron pad we could reach short sample at 1.9 K and 12 T.
Jc(B, 4.2 K)

6. CD1 Mechanical Design Simulations for 1.9 K at short sample current.
Stainless steel pad closed at all stages.

7. CD1 Mechanical Design Former azimutal stress under Lorentz force
Cond. azimutal stress under Lorentz force
Cond. radial displ. under Lorentz force
-220/+206* MPa
-82/+87 MPa
110 µm
Former stress rises for sliding intra-layer contacts and for iron pads. Worst-case: -284/+408 MPa under Lorentz forces.
* … Al-bronze, yield strength at room temperature: ~400 MPa

8. CD2 Magnetic Design
Imax = 20 kA; 9 T bore field, 73% on loadline at 4.2 K.
ISS for steel pads at 4.2 K is 27 kA, 11.5 T bore field.
For iron pad: 10 T, 80% on loadline at 4.2 K.
Jc(B, 4.2 K)
Imax limited by test station. Cable is oversize for a 2-layer magnet.

9. CD2 Mechanical Design
Former azimutal stress
under Lorentz force
Cond. azimutal stress under Lorentz force
Cond. radial displ. under Lorentz force
All values remain low due to power-converter limitation.
(To be checked also at short-sample current.)

10. CD2 in MDP 15-T Layers 3&4 BSS = 15.4 T (Iss = 12.8 kA) at 4.2 K .
BSS = 16.8 T (Iss = 14.1 kA) A at 1.9 K.
Field quality not optimized (140 units b3), peak field on midplane.

11. First Planning

12. Fabrication Risks CD1: CD2: lack of experience of PSI team
scheduling of coil-manufacturing operations (capabilities at PSI, resources at LBNL or CERN)
CD2:
windability  winding tests with 15-T IL cable asap
former manufacturing

13. Conclusion and Next Steps
2-D design mostly finished.
Pad material to be decided.
3-D periodic mechanical models ready for use.
3-D full model under preparation in collaboration with Lucas Brouwer (LBNL).
Former manufacturing process-development started with IWS Fraunhofer institute, Dresden, Germany.
Next steps:
Conceptual Design Review.
CD1 technical design.
Short mechanical model.
CD1-coil impregnation & reaction tests.
CD2-coil winding tests.
CD2 conductor order. …

14. End