1. P.Fabbricatore & S.Farinon
Status of D2 development
P.Fabbricatore & S.Farinon
INFN Genova
2D Mechanical design
3D magnetic design
Engineering studies

2. Configuration INFN_3_3_6 2D Lay-outDx Dy R Rh

3. 2D Magnetic Design
I briefly remind that a 2D design magnetic design was performed in 2014 based on three pillars:
No iron is placed in between the coils (so limiting saturation effects);
Each coil is asymmetric in a way to cancel the magnetic cross talk each other.
The yoke is suitably profiled for keeping constant the harmonic components

4. Main Characteristics 1 Characteristics Units Value Aperture mm 105
Number of apertures 2
Distance between apertures (cold/warm)
188.00/
Cold mass outer diameter (min/max)
570/630
Magnetic length m
7.78
Bore field T
4.5
Peak field
5.20
Current kA
12.050
Temperature K
1.9
Loadline margin
(%) 35
Overall current density
A/mm2
443
Stored energy per meter
MJ/m
0.2807
Differential inductance per meter
mH/m
3.509
Stored energy MJ
2.18
Differential inductance mH
27.3

5. Main Characteristics 2 Characteristics Units Value Superconductor
Nb-Ti
Strand diameter mm
0.825
Cu/No Cu
1.95
RRR
>150
Superconductor current density at 10 T, 1.9 K
A/mm2
2100
Number of strands per cable 36
Cable bare width
15.1
Cable bare mid thickness
1.480
Keystone angle
degrees
0.90
Insulation thickness per side radial
0.160
Insulation thickness per side azimuthal
0.145
Number of layers 1
Number of turns
31=
Cable unit length m
520
Coil physical length
8.2
Magnet physical length
8.5
Cold mass weigth t 17
Heat exchanger hole diameter 40
Heat exchanger angle 90
Heat exchanger distance from centre
237
Fx (per quarter, per aperture) [left right]
MN/m
0.60/0.68
Fy (per quarter, per aperture)
-0.40

6. b2 and b3 fine shim
Adding a second hole, b2 and b3 are lowered of 2 and 1 unit respectively. This second hole could be filled with iron if not required

7. Lay-out and 2D mechanical design
Last time we showed a solution with a single collar. Not satisfactory because the complexity of the assembly. However this solution is still there as plan B in case of major problems with a new double collar option.
Mechanics: Single collar. An ‘old’ option still alive as plan B

8. New lay-out with a double collar option
Aluminum alloy ring 6061-T6 or 7075-T6 made of short elements mm. At room temperature the gap with collared coils is 0.2 mm
Collars made of austenitic steel type YUS 130 S
(Dl/l = )
Much better if we could use
KHMN (Dl/l= )
Centering the collared coils
Centering the core with iron
Collars with nose. It allows future coil modifications without changing the main collar structure
Clamps and welded stiffening bars

9. plastic properties 0.6 mm gap winding collars Al alloy ring iron yoke
[MPa]
seqv sq
(key zone)
(nose zone) 2
collaring (F=386 tons/m)
peak
212
-200
581
788 ̅
ave 85
-90 93 6
releasing pressure
213
-202
744
458 76
-81 54 8
closing of yoke (F=377 tons/m)
201
-209
833
716
289
114 78
-83 70
170 28 13
187
-176
809
401
222
384 77
-82 94 26 14
cool-down
149
-139
576
459
220
330 52
-52 43 12 15
energization to 4.5 T
-103
560
331
218
221
-55 30 19

12. (studied on a previous version)
Mechanical effects on b2 and b3 field harmonics
(studied on a previous version)

13. Coil end design is 90% done
End with connections

15. End with no connections

16. b3 (black) and a3 (red) components in the connection end
Integrated harmonics still to be optimised (ex. b3 int. -5 unit in half coil with connection end )

17. Presently we have engineering drawings of the 2D cross section

18. Activity within the INFN project MAGIX
1) 2D magnetic design Jul
2) 3D magnetic design (coil ends) Dec
2) 2D mechanical design Dec
3) Quench analysis Sep
4) 3D mechanical design (axial pre-stress) Dec
5) Enginering design of a short model Dec
6) Engineering Design long Dec
CERN General Schedule for D2

19. Conclusions
The 2 D magnetic and mechanical designs were completed
The 3D magnetic design is close to be completed
Still to do: 3 D mechanical design, 3D engineering and Quench analyses