Shearing and Hartmann Wavefront Sensors for Diffraction-Limited Beamlines
Design and upgrade of wavefront sensors for diffraction-limited beamlines at various national laboratories, focusing on advanced light sources and soft X-ray applications. The sensors aim to monitor wavefront perturbations and optimize beam quality for enhanced performance. Various sensor designs and beamline configurations are discussed, highlighting the importance of accurate wavefront measurements in maintaining diffraction-limited conditions.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
E N D
Presentation Transcript
Design of shearing and Hartmann wavefront sensors for diffraction-limited beamlines Antoine Wojdyla1, Diane Bryant1, Kenneth A Goldberg1, Lahsen Assoufid2, Daniele Cocco3, Mourad Idir4 1ALS, Lawrence Berkeley National Laboratory, Berkeley, California 94710, USA 2APS, Argonne National Laboratory, Argonne, IL 60439, USA 3LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94566, USA 4NSLS-II, Brookhaven National Laboratory, Upton, NY 11973-5000, USA June 15th, 2018 SRI 2018, Taipei, Taiwan SXR wavefront sensor designs - A Wojdyla SRI 2018
Upgrade of the Advanced Light Source to a diffraction-limited storage ring Soft X-ray + Tender X-ray (260-1400eV, 1-5keV) Large coherent fraction Diffraction-limited Completion ca 2024 SXR wavefront sensor designs - A Wojdyla SRI 2018 2
DLSR light sources Diffraction-limited beam ~ /4 Small footprint and small divergence Continuous monitoring of the beam: the wavefront sensor has to be placed before the object (no post-object diverging beam) SXR wavefront sensor designs - A Wojdyla SRI 2018 3
Perturbations of the wavefront High heatload causes deformation ?/16 phase 1mm Mirror error figure (older optics, for adaptive correction) 1mm 1m COSMIC M111 tilt +1mrad Fine alignment of optics Misalignments have a signature tilt defocus astigmatism coma SXR wavefront sensor designs - A Wojdyla SRI 2018
A zoo of beams LCLS ALS/COSMIC ALS-U/Flagship 1 ALS-U/Flagship 2 NSLS-II APS-U ALS-U/Flagship TXR SXR wavefront sensor designs - A Wojdyla SRI 2018
Wavefront sensors Grating-based Liu E.1.2, Wed 13h50 Hartmann grid Scholze E.1.6, Wed 15h20 Pl njes, IWXM Speckle-based Wang E.1.4, Wed 14h30 SXR wavefront sensor designs - A Wojdyla SRI 2018 6
Wavefront sensors for soft x-ray No phase gratings and speckle, no crystals ALS-U SXR Notional beamline(250-1400eV) non invasive : able to work on convergent geometry After Mono, M3 Can be limited to the non-dispersive direction Stay clear of the beam elliptical-cylinder x-focusing mirror WFS monochromator WFS 4-m-long undulator beam plane mirror z diagnostics x-y slit SXR wavefront sensor designs - A Wojdyla SRI 2018
Design of wavefront sensors Design constraints beam footprint detector resolution beam overlap Beamline (footprint, propagation distance) Performances range sensitivity efficiency Beam Optical elements (pitch, pixel size) (wavelength, NA) SXR wavefront sensor designs - A Wojdyla SRI 2018
Design constraints Lateral shearing interferometry Hartmann sensor ZCCD No diffraction (amplitude sensitivity) beam overlap pitch too large Talbot plane too far ZCCD pitch too small pixel size too small shadow regime diffraction regime SXR wavefront sensor designs - A Wojdyla SRI 2018
Distance of operation Wavefront sensors operate in the Fresnel regime: z a2/ The critical dimension a is 10 40 m for any reasonable distance of operation (0.1-1m) for most photon energies (0.2-10keV) Direct detection (pixel size 15 m) becomes difficult: scintillator-based detection (YAG:Ce) SXR wavefront sensor designs - A Wojdyla SRI 2018 10
Shearing interferometry with a converging beam d0 Pattern size: d = d0 (zF-z)/zF (pitch x demag) Pattern shift: = /d0 z (divergence x distance) zF z +1 0 -1 Talbot length: zT d02/ zC Converging Talbot distance: d(zC) = (zC) .. /d0 zC = d0 (zF-zC)/zF .. .. /d02 = (zF-zC)/zFzC .. .. .. 1/zT = 1/zC - 1/zF 1/zC = 1/zT + 1/zF SXR wavefront sensor designs - A Wojdyla SRI 2018 11
Typical designs for ALS-U M3 beam- splitter Maintain 4 6 mm center-to-center separation beam separation from reflection gratings beam separation from reflection gratings 8 8 separation at 2 meters [mm] separation at 2 meters [mm] 6 6 4 4 pitch pitch 10 m 15 m 22 m 33 m 52 m 80 m 120 m 180 m 2 2 0 0 0.2 0.4 0.6 0.8 1.0 1 2 3 4 5 wavelength [nm] wavelength [nm] SXR wavefront sensor designs - A Wojdyla SRI 2018
Soft x-ray shearing interferometer Currently being assembled and tested SXR wavefront sensor designs - A Wojdyla SRI 2018
Soft x-ray Hartmann sensor 20 m holes, 162 m grid, direct detection Designed by Imagine Optic 13.5 m pixels 500eV, FWHM = 50 m data shot-noise limit spot position error [ m] counts per spot [ADU] [ m]=0.21 x FWHM[ m] / sqrt(Nph) SXR wavefront sensor designs - A Wojdyla SRI 2018
Tender x-ray Hartmann sensor Scintillator-based YAG:Ce Optimized for 2-10keV In collaboration with Imagine Optic SXR wavefront sensor designs - A Wojdyla SRI 2018
Thank you for your attention! Many thanks to: Lei Huang (BNL) Julia Aquila (LBNL) Walan Grizolli (BNL) Weilun Chao (LBNL) Eric Gullikson (LBNL) Tony Warwick (LBNL) Ruben Reininger (ANL) Howard Padmore (ALS) Valeriy Yashchuck (LBNL) Luca Rebuffi (Sync Trieste) Dietmar Korn (Imagine Optics) Manuel Sanchez del Rio (ESRF) Guillaume Dovillaire (Imagine Optic) Acknowledgments This work is supported under DOE contract DE-FOA-0001414 and performed by the University of California, Lawrence Berkeley National Laboratory under the auspices of the U.S. SXR wavefront sensor designs - A Wojdyla SRI 2018 Department of Energy, Contract No. DE-AC02-05CH11231.
We are looking for collaborators, and hiring engineers. We need you at ALS-U! jobs.lbl.gov We are looking for collaborators SXR wavefront sensor designs - A Wojdyla SRI 2018
6th International Diffraction Limited Storage Ring (DLSR) Workshop October 29-31, 2018 Berkley, CA (USA) Registration open: bit.ly/dlsr2018 contact: awojdyla@lbl.gov SXR wavefront sensor designs - A Wojdyla SRI 2018
Hartmann sensor in converging geometry Wavefront sensor Toroidal mirror Example of projection of the Hartmann grid on the CCD camera reconstructed wavefront 1mm q=2.2m d=0.7m We have conducted the experiments on the COSMIC beamline scattering branch, at a photon energy of 490eV. We tilted the last toroidal mirror by +/- 500urad to observe the change in astigmatism and determine best angle. Wavefront with defocus removed (astigmatism-dominated) Wavefront with astigmatism removed (coma-dominated) SXR wavefront sensor designs - A Wojdyla SRI 2018
Fine alignment with WFS Simulations with OASYS/Shadow astigmatism tilt -1mrad tilt +1mrad Zernike coefficient [a.u.] Zernike coefficient [a.u.] tilt defocus astigmatism coma coma Zoll index Zoll index SXR wavefront sensor designs - A Wojdyla SRI 2018
Slide from K Goldberg Reflection-grating beam-splitter Duty cycle controls diffraction efficiency. M3 beam- splitter binary grating: relative power into orders phase grating: relative power into orders 1.0 1.0 0 1 ratio 1/ 0 0.8 0.8 operate here relative power relative power 0 1 ratio 1/ 0 0.6 0.6 0.4 0.4 0.2 0.2 0 0 0 0.2 0.4 0.6 0.8 1.0 0 0.2 0.4 0.6 0.8 1.0 duty cycle, duty cycle, Example calculated for = 1 nm, = 1 , And 5 nm surface relief. Non-invasive WFS goal SXR wavefront sensor designs - A Wojdyla SRI 2018 high ??and low ??
Scintillator efficiency YAG:ce yield ~10phvis/phSXR Collection efficiency (0.12NA)^2/2: 0.72% incoherent efficiency 5x demag Small distortion (<1px) 2e- dark noise SXR wavefront sensor designs - A Wojdyla SRI 2018 22
