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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. Permanent Magnet Damping Wiggler
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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 • Permanent Magnet Damping Wiggler • Fanning angle reduction, damping effect adjustment • Elliptically Polarized Undulator (EPU) • 3 Pole Wiggler • Cryo-Permanent Magnet Undulator (CPMU) • Cold Measurement System • New Magnet / Pole Materials • New Gap Separation Mechanism • Superconducting Insertion Devices • SCU, SCW and SEPU • High Temperature Superconductor (HTS)
1) PM-Damping Wiggler • CDR DW (lw=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/g = 2.71 mrad • New Design with side magnets (lw=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 / g = 2.32 mrad Side Magnets W100 W80
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 • 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 16mm 17.5mm Br=1.35T Permendur Center Pole Soft Iron (1006) Side Poles Rectangular Magnets S [mm]
4) CPMU Japanese/European Efforts on Cold Measurement System SPring-8 (Courtesy of T.Tanaka) ESRF (Elettra Workshop 06)
New Materials for CPMU • Latest PrFeB Magnet • New CR53 from Hitachi Metal • New Pole Materials • Single Crystal Dy: Very high saturation flux density ~ 3.5T (if aligned) • Er-Ho-Dy alloy ~ 3T • Vanadium permendur ~ 2.34T • Soft iron ~ 2.1T
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 TemperatureSuperconducting 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.
Superconducting Wiggler • CDR-SCW • 17 pole @ 6.0T (lu=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.