1. Permanent Magnets Y. Iwashita Kyoto University

2. PMQ with saturated iron pole B=2Br (1-r 1 /r 2 ) cos 2 (π/M) sin(2π/M) /(2π/M)

3. First prototype (fixed field)

5. Adjustable Permanent Magnet Quadrupole Permanent Magnet (NEOMAX38AH)

6. Drawing

7. Prototype Magnet

8. Photos

9. Magnetic Center Movement Magnetic Center moves by tens of micron when the strength was changed.

10. Configurations for Various Crossing Angles Incoming Beam Table II PMQ parameters for various crossing angles.

11. Demagnetization by Radiation Continuous 1 mo. operation may cause about 0.01[%] of (reversible?) demagnetization on NEOMAX 32EH.

12. Effect of Solenoid solenoid coil back coilmagnetic shield Integrated strength is reduced by Solenoid field because PMQ has pole (vanadium permendur). Back coil and/or some shield is needed.

13. Recent Modification Demonstrate a higher field gradient by reducing the bore size from ø20mm down to ø15mm. Temperature compensation of the inner ring; 1 mm (left) and 1.6 mm (right) MS-1 trapezoidal plates are seen in a 2cm space between magnets.

14. Longitudinal Distribution with IDø15

15. Rotating Coil Stand AC servo-motor with encoder (up to 600 RPM)

16. What’s next? Finish magnetic field measurement system Fabricate third model Sextupole? Octpole? more?

17. Rotating PMSx for cold neutrons Cold neutron beam can be focused by strong sextupole. 25Hz for ToF.