Permanent Magnet Quadrupole Lens with Variable Strength Yoshihisa - - PowerPoint PPT Presentation

AccLab NSRF ICR KyotoUniversity

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
• Title

ICFA Nanobeam02

AccLab NSRF ICR KyotoUniversity

• PMD & B-H curve

Beam axis

Halbach's dipole REC magnet. B=Br ln(r1/r2) cos( /M) sin( /M)/ 1.37 T @r1, r2=1cm, 4cm

0.0 0.5 1.0 1.5 2.0 2.5 3.0

• 200
• 100

100 200 300 400

B [T] Soft iron B [T] NEOMAX35 B [T] H [k A/m]

AccLab NSRF ICR KyotoUniversity

Fe Beam axis

Modified Halbach's magnet.

• SuperPMD

1.64 T @r1, r2=1cm, 4cm (was 1.37T)

AccLab NSRF ICR KyotoUniversity

• 4.45T Dipole
• M. Kumada et al., CERN Courier, vol. 41, no.7,Sep. 2001, p. 9

Achieved 4.45T @-29 C (3.9T @room temperature)

AccLab NSRF ICR KyotoUniversity

• PMQ & iPMQ – Gradient (Field plot)

iPMQ16 16seg ID=6 OD=24 CY CLE = 7

Fe 10 120 ID:ø20 OD: ø240

B=2Br (1-r1/r2) cos2( /M) sin(2 /M) /(2 /M)

0.0 0.5 1.0 1.5 2.0 2.5 0.2 0.4 0.6 0.8 1

By (iPMQ1 w/Permendur) By (iPMQ w/Fe) [T] By (PMQ16) [T]

By X PM only 2.2 [T/cm] with Permendur 2.5 [T/cm] with Fe 2.4 [T/cm]

AccLab NSRF ICR KyotoUniversity

• IP

Superconducting Q Room temp. Q

AccLab NSRF ICR KyotoUniversity

0m IP

ø10

Module1 Module4 4m

8 m rad

2m ø40 ø48 ø56 Module2 Module3

leaving beam incoming

ø32

• Final Focus PMQ

need some mergine for leaving beam

AccLab NSRF ICR KyotoUniversity iPMQ16 16se 0 .5 OD = 4.0 CY CLE = 6

• Let the beam go through

iPMQ16 16seg 0 .5 OD = 4.0 CY CLE = 7 iPMQ16 16seg .5 OD = 4.0 CY CLE = 7 iPMQ16 16seg .5 OD = 4.0 CY CLE = 7

ixPMQ xPMQ1 xPMQ2 nPMQ

sPMQ16 16seg ID= 0 .5 OD = 1.3 LE = 6

sPMQ

0.0 0.5 1.0 1.5 2.0 0.1 0.2 0.3 0.4 By [T] ixPMQ By [T] nPMQ By [T] xPMQ2 By [T] xPMQ1 By [T] sPMQ By [T] X [cm]

Beam pipe for leaving beam?

AccLab NSRF ICR KyotoUniversity

• Final Focus vPMQ

0m IP

ø10

Module1 ø32 Module4 4m

8 m rad

2m ø40 ø48 ø56 Module2 Module3 F F F F F • • • • • F D F D F • • • • •

leaving beam incoming 5~10cm/unit —> 20~40units/2m ... some units may be fixed strongest F F F F F F F F F F • • • • •

• • •

middle1

F F F D F D F D F D • • • • •

middle2

F D F D F D F D F F F • • • • •

• • •

weakest

F D F D F D F D F D • • • • •

centroid move

}

Stepwise variable Higher resolution by binary increment of the length: 1,2,4,... cm

AccLab NSRF ICR KyotoUniversity

• X-Y stage supplied by NanoControl Co.Ltd.

Piezo Actuator Supersonic Motor or Pneumatic system stroke:15µm/2cm

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

D F F

NdFeB SmCo SmCo 2 : 1 : 2

• Temperature Coefficient Compensation

NdFeB:

• 0.11%/ C

SmCo:

• 0.03~0.04%/ C

Basic idea from E.Antokin x4 difference

}

heat source along the axis

AccLab NSRF ICR KyotoUniversity

• Quad center monitor

Many Hall probes r=5mm beam pipe 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?