1 / 26

Near term opportunities for LCLS 'upgrades'

Near term opportunities for LCLS 'upgrades' . ge x,y = 0.4 m m (slice) I pk = 3.0 kA s E / E = 0.01% (slice). Recent Results! (25 of 33 undulators installed). J. Hastings for the LCLS Experimental Facilities Division June 25, 2009. Goals. Increase user access Multiplex options

kiele
Télécharger la présentation

Near term opportunities for LCLS 'upgrades'

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. Near term opportunities for LCLS 'upgrades' gex,y = 0.4 mm (slice) Ipk = 3.0 kA sE/E = 0.01% (slice) Recent Results! (25 of 33 undulators installed) J. Hastings for the LCLS Experimental Facilities DivisionJune 25, 2009

  2. Goals • Increase user access • Multiplex options • Soft x-rays (800-2000eV) - AMO, SXR • Hard x-rays (up to 25 keV) – XPP, XCS, CXI, MEC • Performance enhancements • Energy range • Long wavelength • Short wavelength • Polarization • Pulse duration • Laser-electron beam interactions

  3. Polarization

  4. CXI X-ray transport tunnel XCS XPP MEC SXR XCS Offset Monochromator AMO

  5. AMO, SXR, XPP, XCS, CXI, MEC Soft X-ray mirrors AMO SXR Hard X-ray mirrors Large offset monchromator Instrument layout

  6. Soft X-ray experiments at LCLS Soft X-Ray Offset mirror system Typical AMO experiments are dilute samples: put re-focusing optics behind AMO: run two experiments in ‘parallel’ (500) 800 eV – 2 keV Beam sharing in place on a ‘12 hour basis’ (mirror deflection between AMO and SXR)

  7. XCS Large Offset Monochromator

  8. XCS Large Offset Monochromator Troika, ID10B, ESRF Kohzu, BL24XU, Spring-8 LUSI Concept

  9. Increased Energy Reach

  10. Baseline: • K = 3.5 • = 3.0 cm • = 8415 (4.3 GeV) 1=1.5 nm • Long wavelength ‘limit’: • K = 3.5 • = 3.0 cm • = 5870 (3.0 GeV) 1=3.1 nm lu lu Long wavelength limit

  11. Si (111) 0.75-Å 1.5-Å 2nd Harmonic Afterburner Increase hard x-ray energy reach 1.5-Å LCLS Undulator afterburner 130 m 43 m 0.75-Å radiation using “spent” LCLS beam, and completely parasitic to LCLS operation at 1.5 Å. Add 40-m, 2nd-harmonic tapered undulator SLAC-PUB-10694. 0.75-Å Parameters: Z. Huang, S. Reiche

  12. Pulse Duration

  13. Polarization Control by Crossed Undulator • Horizontal + vertical undulators or two helical undulators • Polarization controlled by phase shifter, fast switch possible with pulsed dipoles at ~100 Hz -π/2 π/4 -π/4 0 Ex + Ey Phase shifter  π 5π/4 π/2 π/2 • Studies show that equal power in x & y requires L2 = 1.3LG • Over 80% polarization is expected at SASE saturation • Second undulator can be adjusted as a second-harmonic afterburner if needed K.-J. Kim, NIMA 2000 Y. Ding & Z. Huang,PRST-AB 2008

  14. Multiplex options

  15. Thin slotted foil in center of chicane coulomb scattered e- e- unspoiled e- coulomb scattered e- 15-mm thick Be foil PRL92, 074801 (2004). y P. Emma, M. Cornacchia, K. Bane, Z. Huang, H. Schlarb, G. Stupakov, D. Walz (SLAC) 2Dx x DE/E  t

  16. 2 fs fwhm z 60 m Genesis 1.3 FEL code ~1010 photons x-ray Power (<1 fs possible) Power (GW)

  17. SIMULATED FEL PULSES Y. Ding Z. Huang 1.5 Å, 3.61011 photons Ipk = 4.8 kA ge 0.4 µm Simulation at 1.5 Å based on measured injector & linac beam & Elegant tracking,with CSR, at 20 pC. Y. Ding Z. Huang 15 Å, 2.41011 photons, Ipk = 2.6 kA, ge 0.4 µm 20 pC tested J. Frisch 1.2 fs time-slicing at 20 pC Simulation at 15 Å based on measured injector & linac beam & Elegant tracking,with CSR & 20 pC. Measurements and Simulations:20-pC Bunch, 14 GeV MEASURED SLICE EMITTANCE 135 MeV 20 pC gex = 0.14 µm accepted in PRL

  18. Power profile at 25 m Average photon number: 2.4x1011 Estimated time-bandwidth product ~ 3 times Fourier-transform limit.

  19. 30 fs Two-Stage SASE FEL Self-seeding Short pulse, or narrow bandwidth, & wavelength is more stable Moderate – new undulator line or upgrade SLAC-PUB-9370, TESLA-FEL-97-06E, SLAC-PUB-9633, SLAC-PUB-10310 30 Parameters: C. Pellegrini

  20. Laser electron beam interaction

  21. Measuring Bunch Arrival Time Jitter with an RF Deflector V(t) BPM Y Position (mm) TCAV OFF TCAV ON 9 mm rms 110 mm rms Dt±0.6 ps e- S-band (2856 MHz) y-BPM slope = -2.34 mm/deg Now measure BPM jitter with deflector OFF, and then ON (at constant phase) Timing Jitter = (110 mm)/(2.34 mm/deg) = 0.047 deg  46 fsec rms

  22. short pulse train 800-nm modulation (few GW) 24 kA 15-25 kA peak current enhanced x7 70 as Peak current z /lL SASE FEL 4 GeV 14 GeV Allows synchronization between laser pulse and x-ray pulse E-SASE(applied to LCLS) A. Zholents PRL

  23. ESASE in the LCLS Chicane buncher R56 = 0.3-0.8 mm 10-GW laser L = 0.8-2.2 m wiggler ~3 m 10-period 4.54 GeV z 0.02 mm rf gun rf gun Linac-1 L  9 m rf -25° Linac-2 L  330 m rf  -41° Linac-3 L  550 m rf  -10° 13.6 GeV new Linac-0 L 6 m Linac-1 BC1 Linac-2 BC2 Linac-3 Linac-0 undulator L 130 m undulator L 130 m X X …existing linac …existing linac BC1 R5639 mm BC2 R5625 mm DL2 Laser Heater Laser Heater DL2 R560 DL1 R56-6 mm SLAC linac tunnel undulator hall New elements

  24. ESASE single spike selection • Two ten-cycle lasers (second laser tunable wavelength with OPA) • Tapered undulator to compensate LSC and enhance contrast E (MeV) P(GW) Ding, Huang, Ratner, Bucksbaum, Merdji, FEL2008

  25. Special Thanks to: Y. Ding, P. Emma, J. Frisch,Z. Huang, H. Loos, A. Zholents, J. Wu ……

  26. End of Presentation

More Related