1. D2 and Q4 orbit corrector status
J. Rysti, E. Todesco, G. Kirby
25/2/2015

2. Design proposal
25/2/2015

3. Multipoles (both on) Ref. radius 2/3 of aperture = 35 mm
+ few possible units from
manufacturing & assembly
Both apertures powered.
2 layers, 20 mm collars.
Max 1850 A.
25/2/2015

4. Multipoles (1 on & 1 off) 1 2 One aperture powered at a time
2 layers, 20 mm collars
Max 1850 A
25/2/2015

5. Other options Presented baseline has: If only 1 layer:
Self-supporting 20 mm collars (?).
2 layers, 1.7 kA, 45 % I/Iss, 2.8 T bore field.
If only 1 layer:
25 mm collars or more iron => 3 T is achievable.
Need 3.5 kA current, 70 % I/Iss (2.8 T).
Use also the rigidity of the yoke:
Reduce collar thickness & gain more iron.
15 mm collars & 2 layers => can go to 3 T.
25/2/2015

6. Coil ends
25/2/2015

7. Q-protection Straightforward. Dump or CLIQ.
Dump resistor & switch for this range needs development.
1.8 kA, 40 mΩ dump resistor,15 ms delay, Earth: central dump
Green: voltage
Red: hot spot T
Blue: current
Purple & cyan: average T
25/2/2015

9. Extra slides Increase yoke diameter 452 mm => 570 mm.
1 layer, iron yoke, 25 mm collars, 3 T, H/V.
Problem: required current 3.5 kA.
JNbTi = 2900 A/mm2
(~50% SSL)
B = 2.86 T & 2.92 T
I = 3450 A
B = 3.00 T & 3.00 T
25/2/2015

10. Extra slides Jc,NbTi = 6200 A/mm2 @ 3.5 T, 1.9 K
25/2/2015

11. Multipoles (25 mm collar)
Ref. radius 2/3 of aperture
2 layers
25 mm collars
Max 1750 A
25 mm collars too much
25/2/2015

12. Preliminary mechanical analysis
1 layer.
25 mm collars.
Max. radial displacemen at 3T is 37 µm.
Max stress < 70 MPa (need to model keys etc.).
Self supporting collars OK.
25/2/2015

13. Yoke size
To reduce the weight and cost, make yoke as small as possible.
Multipoles reach 10, when yoke diam. 540 mm. => yoke area 87 % of 570 mm case.
Elliptical yoke 588mm x 452mm => 78 % (is it enough that individual multipoles < 10 ?)
If maximum rotated multipoles < 10 => 81 %.
With additional holes and/or cuts can reduce slightly more.
25/2/2015

14. Conclusions ?
25/2/2015