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

2 BROOKHAVEN SCIENCE ASSOCIATES Outline 1)Permanent Magnet Damping Wiggler  Fanning angle reduction, damping effect adjustment 2)Elliptically Polarized Undulator (EPU) 3)3 Pole Wiggler 4)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)

3 BROOKHAVEN SCIENCE ASSOCIATES 1) PM-Damping Wiggler W100 W80 CDR DW ( w =100mm, Gap=15mm) Br= 1.35T Integral of B 2 = T 2.m (90.0% of ideal 1.8T sinusoidal field=0.162 T 2.m) K eff /  = 2.71 mrad New Design with side magnets ( w =80mm, Gap=12mm) Br= 1.30T Integral of B 2 = T 2.m (103% of ideal 1.8T sinusoidal field= T 2.m) K eff /  = 2.32 mrad Side Magnets

4 BROOKHAVEN SCIENCE ASSOCIATES 2) EPU Comparison Apple-II, HiSOR, and other types (Modified Apple-I, Crossed Undulator, etc.) are being compared. Apple-II HiSOR

5 BROOKHAVEN SCIENCE ASSOCIATES 3) 3 Pole Wiggler 16mm17.5mm 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

6 BROOKHAVEN SCIENCE ASSOCIATES 4) CPMU SPring-8 (Courtesy of T.Tanaka) ESRF (Elettra Workshop 06) Japanese/European Efforts on Cold Measurement System

7 BROOKHAVEN SCIENCE ASSOCIATES 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 ~ 2.34T  Soft 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] (Min) Hcb [kA/m] Hcj [kA/m] (BH)max [kJ/m3]349318

8 BROOKHAVEN SCIENCE ASSOCIATES New In-vacuum Gap Separation Mechanism Linear motors drive the outer cage. Vacuum chamber Rail

9 BROOKHAVEN SCIENCE ASSOCIATES 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 MgB 2 etched conductor pattern

10 BROOKHAVEN SCIENCE ASSOCIATES 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.

11 BROOKHAVEN SCIENCE ASSOCIATES Superconducting Wiggler CDR-SCW T ( u =6.0cm, g pole =15.0mm) K peak = 33.6 Critical Photon Energy = 35.9 keV Total Power = kW Peak on-axis angular power density = 36.7 kW / mrad With 1006 Steel, Required Current Density = 1300 A / mm 2 Too much for conventional NbTi wire

12 BROOKHAVEN SCIENCE ASSOCIATES 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.