1 / 13

Reconstruct the FEL x-ray profile with X-TCAV after undulator

Reconstruct the FEL x-ray profile with X-TCAV after undulator. Y. Ding, C. Behrens 3/18/2011. Thanks Zhirong and Paul for helpful discussions. Laser Heater Measurements. I nteraction between laser and electrons in wiggler leads to the increase of energy spread;

rossa
Download Presentation

Reconstruct the FEL x-ray profile with X-TCAV after undulator

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. Reconstruct the FEL x-ray profile with X-TCAV after undulator Y. Ding, C. Behrens 3/18/2011 Thanks Zhirong and Paul for helpful discussions.

  2. Laser Heater Measurements Interaction between laser and electrons in wiggler leads to the increase of energy spread; Use TCAV and dispersion to measure the longitudinal phase space, and know the heating effects. YAGS2 YAGS2 RF deflector ON time energy Laser OFF Laser: 40 µJ σE/E< 12 keV σE/E 45 keV

  3. FEL process leads to e-beam energy loss and energy spread increase We already have the E-loss scan GUI developed by P. Emma to measure the FEL radiation energy from electron beam energy loss. Total_E_loss = E_loss_FEL + E_loss_sr+E_loss_wake+… = E_loss_FEL + E_loss_FELoff Total_EnergySpread = sqrt(ES_FEL^2 + ES_sr^2+ES_wake^2+…) = sqrt(ES_FEL^2+ES_FELoff^2) If we use TCAV to measure the time-resolved e-beam energy loss or energy spread with FEL on and off, then we have the FEL radiation intensity profile. Of course, we also have e-beam distribution profile. • We show a few examples: • Hard x-ray ideal Gaussian beam rms = 7 um; • Hard x-ray ideal Gaussian beam rms = 1um; • Hard X-ray S2E real LCLS beam 3 kA case.

  4. Hard x-ray, Gaussian 7um rms, @ 70m FEL OFF FEL ON Und. exit Und. exit head OTRDMP OTRDMP head

  5. Hard x-ray, Gaussian 7um rms, @ 70m Reconstruct the x-ray profile with the time-resolved E-loss. Reconstruct the x-ray profile with the time-resolved energy spread (after arbitrary scaling).

  6. Hard x-ray, Gaussian 7um rms, @ 110m FEL OFF FEL ON Und. exit Und. exit head OTRDMP OTRDMP head

  7. Hard x-ray, Gaussian 7um rms, @ 110m Reconstruct the x-ray profile with the time-resolved E-loss. Reconstruct the x-ray profile with the time-resolved energy spread (after arbitrary scaling).

  8. Hard x-ray, Gaussian 1um rms, @ 70m FEL OFF FEL ON Und. exit Und. exit head OTRDMP OTRDMP head

  9. Hard x-ray, Gaussian 1um rms, @ 70m Reconstruct the x-ray profile with the time-resolved E-loss. Reconstruct the x-ray profile with the time-resolved energy spread (after arbitrary scaling).

  10. Hard x-ray, 250pC S2E LCLS beam Undulator entrance FEL power profile @ undu. exit

  11. Hard x-ray, 250pC S2E LCLS beam FEL OFF FEL ON Und. exit Und. exit head OTRDMP OTRDMP head

  12. Hard x-ray, 250pC S2E LCLS beam Reconstruct the x-ray profile with the time-resolved E-loss. Reconstruct the x-ray profile with the time-resolved energy spread (after arbitrary scaling).

  13. Discussions • A resolution of 1.5 fs to 3 fs may be achieved for e-beam measurements with X-TCAV; • At the same time, we can have the FEL x-ray profile. • Applicable for all radiation wavelength; • Wide diagnostic range, few fs to few hundred fs; • Profile, single shot; • No interruption with LCLS operation; • Both e-beam and x-ray. • Not cheap… • Slippage at soft x-ray…

More Related