Undulator Development R&D Plan

1 BROOKHAVEN SCIENCE ASSOCIATES

Undulator Development R&D Plan

Toshi Tanabe

George Rakowsky, John Skaritka, Steve Hulbert,Sam Krinsky, Timur Shaftan, and other NSLS-II Staff

NSLS-II

NSLS-II Experimental Facilities Advisory Committee (EFAC)

2007/05/10-11


Outline

1) Permanent Magnet Damping Wiggler Fanning angle reduction, damping effect adjustment

2) Elliptically Polarized Undulator (EPU)3) 3 Pole Wiggler4) Cryo-Permanent Magnet Undulator (CPMU)

Cold Measurement System New Magnet / Pole Materials New Gap Separation Mechanism

5) Superconducting Insertion Devices SCU, SCW and SEPU High Temperature Superconductor (HTS)


1) PM-Damping Wiggler

•W100 •W80

• CDR DW (w=100mm, Gap=15mm)• Br=1.35T• Integral of B2=0.1459 T2.m (90.0% of ideal 1.8T sinusoidal field=0.162 T2.m)• Keff/ = 2.71 mrad

• New Design with side magnets (w=80mm, Gap=12mm)• Br=1.30T• Integral of B2=0.1334 T2.m (103% of ideal 1.8T sinusoidal field=0.1296 T2.m)• Keff / = 2.32 mrad

Side Magnets


2) EPU Comparison

• Apple-II, HiSOR, and other types (Modified Apple-I, Crossed Undulator, etc.) are being compared.

•Apple-II •HiSOR


3) 3 Pole Wiggler

16mm 17.5mm

Main Magnets: 120 x 44. x 90 mm

Center Pole: 120 x 20 x 65 mm

End Poles: 95 x 40 x 86 mm

•Br=1.35T

•Permendur Center Pole

•Soft Iron (1006) Side Poles

•Rectangular Magnets

S [mm]

• Requirements:• More than 2 mrad of radiation fan above 1T field• Use standard gap dipole (35 mm Gap) chamber • Fixed gap and removable from one side of the chamber• Placed next to a BM Cross talk issues are being investigated (3D model)

•Preliminary Magnetic Design


4) CPMU

•SPring-8 (Courtesy of T.Tanaka) •ESRF (Elettra Workshop 06)

•Japanese/European Efforts on Cold Measurement System


New Materials for CPMU

•New Pole Materials• Single Crystal Dy: Very high saturation flux density ~ 3.5T (if aligned) • Er-Ho-Dy alloy ~ 3T

Vanadium permendur ~ 2.34TSoft iron ~ 2.1T

•Latest PrFeB Magnet • New CR53 from Hitachi Metal

Values at RT P-53CR(PrFeB)

42AH(NdFeB, used for MGU-25)

Br [T] 1.35 1.28 (Min)

Hcb [kA/m] 1032 970

Hcj [kA/m] 1361 1909

(BH)max [kJ/m3] 349 318


New In-vacuum Gap Separation Mechanism

Linear motors drive the outer cage.

Vacuum chamber

Rail


5) Superconducting Insertion Devices

• Low Temperature Superconducting Undulator/ Wiggler • Test APC-NbTi wire

• Low Temperature Superconducting EPU• Design study, especially winding technique

• High Temperature SC Devices• Rapid conductor development in the industry• New type such as coated conductor and thin film available More design flexibility• Once the conductor exceeds the necessary performance level, it will be very

promising candidates for future IDs

•YBCO HTS tape undulator

•MgB2 etched conductor pattern


Latest Result

• High Temperature SCU proto type• Siemens HTS 5cm wide YBCO tape slotted (14mm period) is immersed in LN

(77K).• Only one layer, one array, measured at 2mm away from the poles.

HTC tape undulator scan @ 10 amps

-6

-4

-2

0

2

4

6

8

10

12

0 20 40 60 80 100 120 140 160

S [mm]

Gau

ss


Superconducting Wiggler

• CDR-SCW • 17 pole @ 6.0T (u=6.0cm, gpole=15.0mm)• Kpeak = 33.6• Critical Photon Energy = 35.9 keV• Total Power = 102.6 kW• Peak on-axis angular power density = 36.7 kW / mrad

With 1006 Steel,

Required Current Density = 1300 A / mm2

Too much for conventional

NbTi wire


Summary

• DW may require further refinement to reduce the impact on the ring.• Tracking study with realistic field map is underway.

• More tracking studies are required for optimal structure of EPU for NSLS-II.• 3 pole wiggler will be conventional PM device, however;

• Magnetic interaction with adjacent magnets should be taken into account.• Residual dispersion due to asymmetric beta function at the location has be to

minimized.• Development of accurate cold field measurement system is essential for

successful operation of CPMU.• New materials to be developed for higher performance• New gap separation mechanism to simplify the structure

• SC insertion devices planned for NSLS-II require further R&Ds.

Documents

Undulator Development R&D Plan