• Title ICFA Nanobeam02 Permanent Magnet Quadrupole Lens with Variable Strength Yoshihisa Iwashita Accelerator Laboratory, Nuclear Science Research Facility, Institute for Chemical Research, Kyoto University, Gokanosho, Uji, Kyoto 611, JAPAN iwashita@kyticr.kuicr.kyoto-u.ac.jp http://wwwal.kuicr.kyoto-u.ac.jp Contents: • Introduction - Superstrong PMD • PMQ, iPMQ (saturated iron PMQ) • Variable • XPMQ • Sketch • NanoControl AccLab NSRF ICR KyotoUniversity
• PMD & B-H curve Halbach's dipole REC magnet. B [T] B [T] Soft iron 3.0 B [T] NEOMAX35 2.5 2.0 1.5 1.0 0.5 Beam axis 0.0 -200 -100 0 100 200 300 400 1.37 T @r 1 , r 2 =1cm, 4cm H [k A/m] B=Br ln(r 1 /r 2 ) cos( /M) sin( /M)/ AccLab NSRF ICR KyotoUniversity
• SuperPMD Modified Halbach's magnet. Fe 1.64 T @r 1 , r 2 =1cm, 4cm (was 1.37T) Beam axis AccLab NSRF ICR KyotoUniversity
• 4.45T Dipole Achieved 4.45T @-29 C (3.9T @room temperature) M. Kumada et al., CERN Courier, vol. 41, no.7,Sep. 2001, p. 9 AccLab NSRF ICR KyotoUniversity
• PMQ & iPMQ – Gradient (Field plot) 2.5 with Fe 2.4 [T/cm] ID:ø20 2.0 OD: ø240 with Permendur 2.5 [T/cm] 1.5 By PM only 2.2 [T/cm] 1.0 0.5 Fe By (iPMQ1 w/Permendur) By (iPMQ w/Fe) [T] By (PMQ16) [T] 0.0 0 0.2 0.4 0.6 0.8 1 iPMQ16 16seg ID=6 OD=24 CY CLE = 7 0 10 120 X B=2Br (1-r 1 /r 2 ) cos 2 ( /M) sin(2 /M) /(2 /M) AccLab NSRF ICR KyotoUniversity
• IP Superconducting Q Room temp. Q AccLab NSRF ICR KyotoUniversity
• Final Focus PMQ 8 m rad leaving beam IP incoming ø40 ø48 ø56 ø10 ø32 0m 2m Module4 4m Module1 Module2 Module3 need some mergine for leaving beam AccLab NSRF ICR KyotoUniversity
• Let the beam go through sPMQ nPMQ xPMQ2 sPMQ16 16seg ID= 0 .5 OD = 1.3 LE = 6 sPMQ16 16seg ID= 0 .5 OD = 1.3 E = 6 By [T] 2.0 By [T] ixPMQ By [T] nPMQ iPMQ16 16se 0 .5 OD = 4.0 CY CLE = 6 By [T] xPMQ2 CY CLE = 7 iPMQ16 16seg 0 .5 OD = 4.0 1.5 By [T] xPMQ1 ixPMQ xPMQ1 By [T] sPMQ 1.0 0.5 0.0 0 0.1 0.2 0.3 0.4 iPMQ16 16seg .5 OD = 4.0 CY CLE = 7 iPMQ16 16seg .5 OD = 4.0 CY CLE = 7 X [cm] Beam pipe for leaving beam? AccLab NSRF ICR KyotoUniversity
• Final Focus vPMQ 8 m rad F F F F F • • • • • leaving beam F D F D F • • • • • ø32 IP incoming ø10 ø40 ø48 ø56 0m 2m Module4 4m Module1 Module2 Module3 Stepwise variable 5~10cm/unit —> 20~40units/2m ... some units may be fixed Higher resolution by binary increment of the length: 1,2,4,... cm strongest F F F F F F F F F F • • • • • • • • middle1 } F F F D F D F D F D • • • • • centroid move middle2 F D F D F D F D F F F • • • • • • • • weakest F D F D F D F D F D • • • • • AccLab NSRF ICR KyotoUniversity
• X-Y stage supplied by NanoControl Co.Ltd. Piezo Actuator stroke:15µm/2cm Supersonic Motor or Pneumatic system AccLab NSRF ICR KyotoUniversity
• Some issues Strength 10 -5 ? Displacement 0.2 nm ? Rotation (skew) 3µ rad ? above three needs temperature compensation Step size? Multipole component? (dodecapole) Radiation damage? temperature coefficient? Helical Quadrupole(round beam)? AccLab NSRF ICR KyotoUniversity
• Temperature Coefficient Compensation Basic idea from E.Antokin } NdFeB: -0.11%/ C x4 difference SmCo: -0.03~0.04%/ C D F F SmCo SmCo NdFeB heat source along the axis 2 : 1 : 2 AccLab NSRF ICR KyotoUniversity
• Quad center monitor r=5mm beam pipe Many Hall probes Accuracy of 10 -4 may locate the magnetic center with 5 mm x 10 -4 =0.5 µm or better including multipoles. Radiation damage? Dirfts? AccLab NSRF ICR KyotoUniversity
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