1 / 16

Hard X-Ray Wiggler Sources at NSLS-II

Hard X-Ray Wiggler Sources at NSLS-II. Oleg Chubar X-ray source scientist, XFD, NSLS-II Workshop on Preparation of High-Pressure Beamline Proposal April 29, 2010. Wiggler Impact on NSLS-II Electron Beam Parameters.

yasuo
Download Presentation

Hard X-Ray Wiggler Sources at NSLS-II

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hard X-Ray Wiggler Sources at NSLS-II Oleg Chubar X-ray source scientist, XFD, NSLS-II Workshop on Preparation of High-Pressure Beamline Proposal April 29, 2010

  2. Wiggler Impact on NSLS-II Electron Beam Parameters • Two main phenomena associated with the process of Emission of Photons by relativistic Electronsin High-Energy Electron Storage Rings: • Radiation Damping (associated with classical emission) tends to reduce Electron Beam Emittance • Quantum Fluctuations (due to discreteness of the emission “events”) result in the increaseof Electron Beam Emittance and Energy Spread • The “equilibrium” Electron Beam Emittance and Energy Spread is determined by the balance of these two phenomena. Basic Parameters of Electron Beam at NSLS-II If used in dispersion-free straight sections at NSLS-II, high-field wigglers would further reduce e-beam emittance, however would increase energy spread * - Low-Beta section / High-Beta section values

  3. Spectral Brightness of NSLS-II Sources

  4. Spectral Flux of NSLS-II Sources

  5. Wiggler Comparisons: Brightness NSLS-II e-beamassumed: I = 0.5 A εx = 0.55 nm εy = 8 pm

  6. Wiggler Comparisons: Flux per Unit Horizontal Angle

  7. Wiggler Comparisons: Peak Flux per Unit Solid Angle

  8. DW Reference Magnetic and Mechanical Design Side Magnets Magnetic Design with Side Magnets: 90 mm Period, 1.85 T Peak Field at 12.5 mm Gap (T. Tanabe) 3D Magnetic Model (with reduced number of periods) Calculated Magnetic Field (RADIA) Fixed-Gap Conceptual Mechanical Design (proposal of E.Gluskin and E.Trakhtengerg, APS)

  9. 3.5 T SC Wiggler of MAX-Lab The Structure (E. Wallen, Max-Lab) RADIA model with reduced number of periods Peak Magnetic Field vs Horizontal Position Period: 61 mm Magnetic Gap: 10 mm Vertical Magnetic Field on the Axis Peak Magnetic Field vs Vertical Position

  10. Example of Commercially-Available Multi-Pole SCW Figure courtesy of Nikolay Mezentsev (BINP, Novosibirsk, Russia)

  11. Power Output of NSLS-II IDs Power per Unit Solid Angle In Horizontal Median Plane In Vertical Median Plane Total Power: PDW90≈ 67 kW PSCW60≈ 34 kW

  12. Spectral-Angular Distributions of Emission from 2 x 3.5 m Long DW90 in “Inline” Configuration Angular Profiles of DW Emission at Different Photon Energies Spectral Flux per Unit Solid Angle Horizontal Profiles FWHM Angular Divergence of DW Emission Vertical Profiles 1/g ≈ 170 μrad

  13. Wiggler Magnetic Fields and Electron Trajectories DW90 SCW60 Magnetic Field (RADIA) DW90 Modeling Magnetic Field Zoom Typical perturbations due to imperfect magnets: ΔB/Bmax~3 x 10-3 (magnet specs: ΔBr/Br <10-2) Horizontal Trajectory: Angle Suggested Tolerance for Horizontal Trajectory in DW: |x| < 120 μm (max. allowed deviation from “straightness”: 20 μm) Horizontal Trajectory: Coordinate

  14. Example of SCW Parametric Optimization(for SOLEIL High Pressure Beamline) Photons/s/0.1%bw/mr2 at  = 50 keV W/mr2 at 20 keV <  < 100 keV MAX-Lab / BINP SC Technology Limit (gap >10 mm) MAX-Lab / BINP SC Technology Limit (gap >10 mm) ACCEL SC Techn. Limit (gap 10 mm) ACCEL SC Techn. Limit (gap 10 mm) Hybrid/PM Technology Limit (gap 10 mm) Hybrid/PM Technology Limit (gap 10 mm) x max = 8 mr x max = 8 mr x min = 2 mr x min = 2 mr Spectral Flux Per Unit Horizontal and Vertical Angles from Wigglers with Different Periods and Peak Fields at the Constraints on the Total Emitted Power Pmax = 30 kW, and the Total Length L  2 m E = 2.75 GeV, I = 0.5 A, Sinusoidal Field • “Technology Limits” Data taken from: • presentations by N.Mezentsev (BINP) and S.Kubsky (ACCEL) • hybrid wiggler simulations by O.Marcouille u 44 mm, Np 42 Bmax  2.6 T F  1.2 x 1015 Ph/s/0.1%bw/mr2 u 35 mm, Np 44 Bmax  2.85 T F  1.6 x 1015 Ph/s/0.1%bw/mr2 SOLEIL, 2005

  15. In-Vacuum Wiggler W50 3D Magnetic Model (reduced number of periods) On-Axis Flux per Unit Solid Angle [Ph/s/0.1%bw/mrad2] Photon Energy: 50 keV Pmax = 25 kW; L = 2 m O. Marcouille EPAC2008 Approx. “Technology Curves” CAD Drawing On-Axis Magnetic Field Magnetic Force vs Gap

  16. Example of Spectral Performance of Optimized SCW(for SOLEIL High Pressure Beamline) Ptot 30 kW, L  2 m for all structures Ptot 20 kW for all structures Spectral Flux per Unit Horizontal and Vertical Angles Wiggler for NSLS-II High Pressure Beamline could be similarly optimized to provide maximal flux (per unit solid angle) in users’ spectral domain of interest, while satisfying all accelerator physics constraints.

More Related