Exsitu NMR LDRD Progress report 012703

1
Ex-situ NMR LDRD Progress report 01/27/03

• Magnetic and mechanic design
• Paolo Ferracin

2
Field calculation for a line current
y

• 2D azimuthal component of
• the field
• Only odd normal (b3, b5, b7,) and even skew (a2,
  a4, a6,) harmonics.

- I
I
a
p (r, J)
F
x
3
Line currents in NMR configuration

• Distance from the sweet spot d.
• Distance from the y axis t.
• We move the line currents horizontally.
• We compute, for a given d and t, the field
  harmonics.

4
Main field
y
5
Skew quadrupole
y
6
Normal sextupole
y
7
Comments

• Comparison of the curves with Roxie
• line currents perfect agreement
• blocks (? 20 ? 20 mm) with d ? 30 mm very good
  agreement
• You can cancel either a2 or b3 with 2 horizontal
  coils (with the same current)
• ? ? ? ?
• You can cancel both a2 and b3 with 3 horizontal
  coils (with the same current)
• ? ? ? ? ? ?

8
2D analysis HD and RD

• HD RD
• NbTi cables.
• Distance d 40 mm, total width ? 200 mm.
• Main field 2000 ? 3000 Gauss.
• Field homogeneity (without full optim.)
• R 5 mm ? 10-3
• R 1.5 mm ? 10-4 ? 10-5.

9
2D analysis SM coils, upper part

• Nb3Sn cables.
• Distance d 40 mm, total width ? 200 mm.
• Main field 6000 Gauss.
• Field homogeneity
• R 5 mm ? 10-3
• R 1.5 mm ? 10-4 ? 10-5.

10
2D analysis SM coils

• Nb3Sn cables.
• Distance d 40 mm, total width ? 200 mm.
• Main field 2000 ? 3000 Gauss (return current
  effect).
• Field homogeneity
• R 5 mm ? 10-3
• R 1.5 mm ? 10-4 ? 10-5.

11
3D analysis SM coils

• Main field 2000 ? 3000 Gauss.
• Field quality
• strong 3D effect of the ends.
• Cube of 3 mm side
• By 10-4 homogeneity
• Bx and Bz 0.01? By.
• Work in progress
• coil geometry optimization
• effect of the iron (2D performed).

12
3D analysis SM coils
10-4
10-4
Byy
Byx
Bx
Bz
13
Mechanical design Lorentz forces

• Fx (internal coil) - 0.3 MN.
• Fx (two external coil) 0.5 MN.
• Fx in the SM 0.6 MN.
• Assuming
• shell 20 mm thick (upper limit) and 100 mm long
• shell azimuthal stress at cold 100 MPa
  (cool-down)
• ? Fx on the coils 0.4 MN.