1. Alexander Kalimov, State Polytechnic University, St.-Petersburg
3D Properties of cos-theta Quadrupole in Comparison to Superferric Quadrupole
Alexander Kalimov,
State Polytechnic University, St.-Petersburg
January 2009

2. Main requirements
A.Kalimov, GSI, 22 January 2009

3. 2D design of the cos-theta magnet
A.Kalimov, GSI, 22 January 2009

4. Field characteristics (2D)
Magnetic field along the line
r=375 mm, dB/dr = 5 T/m
Field harmonics in the aperture
(r=200 mm)
A.Kalimov, GSI, 22 January 2009

5. 3D model of the cos-theta magnet
A.Kalimov, GSI, 22 January 2009

6. Integral field quality
Field harmonics 2D 3D
Corrected 3D
Integral field quality
A.Kalimov, GSI, 22 January 2009

7. Field characteristics
Field integrals along
r = 190 mm
Field along z-axis
A.Kalimov, GSI, 22 January 2009

8. Cross section of the superferric magnet
A.Kalimov, GSI, 22 January 2009

9. Field quality (2D)
A.Kalimov, GSI, 22 January 2009

10. Field harmonics
A.Kalimov, GSI, 22 January 2009

11. Quadrupole magnet with 12-pole corrector
12-pole corrector improves
the field quality at high gradients
A.Kalimov, GSI, 22 January 2009

12. 3D model of the superferric magnet
A.Kalimov, GSI, 22 January 2009

13. Integral field quality (1.2 m)
Integral field quality satisfy requirements only
For dB/dr < 8 T/m
A.Kalimov, GSI, 22 January 2009

14. Required accuracy of the coil positioning
Tolerances
Required accuracy of the coil positioning
is about ± 1mm
A.Kalimov, GSI, 22 January 2009

15. Mutual influence of the magnets
Distance between yokes > 250 mm
A.Kalimov, GSI, 22 January 2009

16. Summary
1. Both concepts of the SuperFRS quadrupoles – cos-theta and superferric are in principle acceptable.
2. Advantages of the cos-theta magnet:
High field quality, week saturation effects;
Correction 12-pole coils are not necessary;
Possibility to combine several magnets inside the same yoke;
Smaller outer diameter and total weight.
3. Advantages of the superferric magnet
Simple coils;
Requirements to tolerances are not so strong (~±1mm for coils);
Quickly decreasing fringing fields, the magnet is shorter.
A.Kalimov, GSI, 22 January 2009