1. Vincent Roger, Siarhei Yurevich, Cecilia G. Maiano, Mario Sapinski
CASE STUDY 2
Goal Design a Nb-Ti superconducting quadrupole with an 120 mm aperture for the upgrade of the LHC interaction region operating at 1.9 K
Vincent Roger, Siarhei Yurevich, Cecilia G. Maiano, Mario Sapinski

2. CASE STUDY 2
Determination of the maximum Gradient :

3. CASE STUDY 2 Determination of the maximum Gradient : 150 T/m
Coil’s parameters choosen : 2 layers of 15.2 mm width
Strand diameter Ø 0,8 mm
38 strands per cable
Cu to SC Ratio 1,6
Pitch angle 15,19 deg
keystone angle 0.64 deg
Coil’s parameter calculated : 2 layers of 14,8 mm width
Cable’s thickness 1,45 mm
Add: Keystone angle
Thickness compaction : -9,375 %
Width compaction : -4,56 %
K = 0,28

4. CASE STUDY 2 Determination of the Short sample conditions :
j sc_ss : 1766 A/mm2
j o_ss : 500 A/mm2
I ss : A
G ss : 144,5 T/m
B peak_ss : 9,4 T

5. CASE STUDY 2
Determination of the Operational conditions (80% of jss) :
j sc_op : 1413 A/mm2
j o_op : 400 A/mm2
I op : A
G op : 115,3 T/m
B peak_op : 7,5 T
Margin :
j o_margin : 400 A/mm2
B peak_margin : 2,5 T
T margin : 2,3 K

6. CASE STUDY 2 Margin with NbTi strands : j o_margin : 400 A/mm2
B peak_margin : 2,5 T
T margin : 2,3 K
Margin with Nb3Sn strands :
j o_margin : 600 A/mm2
B peak_margin : 3,2 T
T margin : 4,8 K

7. CASE STUDY 2 Determination of the Lorentz forces : Fx : 630 kN/m
Fy : kN/m
Accumulated stress on the coil mid-plane :
σθ max : -52 MPa
Thickness of the yoke :
t=r2*Gss/2Bsat
t : 130 mm
Thickness of the collar:
t : 40 mm