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Edit Comment Close Premium member Presentation Transcript Photon Beamlines and Diagnostics 2010 : Photon Beamlines and Diagnostics 2010 Meeting Summary Optics : Optics To preserve the coherent wavefront of the FEL pulse To achieve diffraction limited focii Limit or control the phase error Need nm level height errors Metrology «» Manufacturing Manufacturer and end-user collaboration Classical polishing Spheres with <0.2 µrad slope errors Deterministic figuring IBF, EEM Large substrates Fast figuring - ELID Fast metrology - stitching interferometry for 2-D maps Optics “beyond the mirror” : Optics “beyond the mirror” Diamond optics for use in an X-Ray cavity FEL Need “perfect” crystals 4 needed for tunable FEL Demonstrated the required 99% reflectivity is achievable Feedback control to stabilise angle also proven Cryo cooling to reduce heat deformation Proven technologies, no reason XFELO should not work Optics “beyond the mirror” : Optics “beyond the mirror” Multilayers Large NA in the hard X-ray Improved reflectivity More convenient geometry Delay lines Smaller optics Spectral filtering (isolate harmonic) Beam splitters BW match to FEL pulse Damage (Mo:Si) Thermal in nature - diffusion Use experience with EUV lithography Optics / Metrology : Optics / Metrology There is a limit to what can be made by direct figuring Change the shape with a bender Allow more extreme shapes Allow change in focal length Be clever when setting up the bender Measure response function of each actuator - derive response matrix Can work out which actuator to use to correct residual errors, shift FL etc. Saves a lot of time! Accuracy depends on quality of original measurements More accurate metrology, lower systematic errors Optics / Metrology : Optics / Metrology Why stop at just defining the basic mirror shape with a bender? Add actuators along mirror surface to give control to smaller spatial frequencies Deterministic control Find response matrix with metrology Dial in required figure More degrees of freedom = better figure accuracy Adaptive control Phase compensator Deform mirror to correct for errors in a downstream mirror In situ interferometry Metrology : Metrology Profilers - the end-users favourite Accuracy 0.05 µrad for flats (10x improvement) Known through comparative measurements to ESAD (Deutsch national standard) 0.1 to 0.2 µrad for spheres Systematic errors more problematic Characterize with angle comparator Not the best choice for the manufacturer (too slow) Metrology / Diagnostics : Metrology / Diagnostics Hartmann wavefront sensors Developed technology for XUV and SXR Commercially available Simple Hartmann plate (no micro lenses) Calibrate with spherical wavefront from pin hole HXR more difficult - convert to optical Calibration more critical (imaging optics) and harder to achieve (can’t make spherical wavefront) Measuring beam wavefront allows determination of source properties Metrology / Diagnostics : Metrology / Diagnostics Grating interferometry At-wavelength metrology of optics with 10 nrad sensitivity Source characterisation Longitudinal position to 1 m Shot-by-shot potential Facilitated by advanced nanofabrication techniques But an instrumentally simple and robust diagnostic Photon Beam Transport : Photon Beam Transport Time preserving monochromators A diffraction grating stretches a pulse Double grating systems Complete reversal of pulse stretch Complicated, reduced efficiency Conical diffraction Pulse stretch down to few fs The only practical single grating solution in VUV to XUV Working example on HHG source (RAL) Classical diffraction mount (match to FEL source in SXR) Also few fs pulse stretch Conceptual only Needs model of FEL source >~250 eV only Photon Beam Transport : Photon Beam Transport Multi-beam experiments (TIMER) Beam splitters Wavefront (knife-edged mirror) Harmonic (multilayers) Delay lines Multilayer Multiple mirrors to vary angles Three beams coincident in time and space at the experiment, with defined angles and energies Photon Beam Transport : Photon Beam Transport HHG Seeding Essential for single mode SXR FELs (?) Successful demonstration at SCSS Test FEL and SPARC As demanding as a user beamline Focus and spatial overlap with electron beam Steering and focusing mirrors Temporal overlap Diagnostics Spectrometer, position & angle SXR Beamlines : SXR Beamlines Use with a FEL source Reduce the bandwidth of a SASE pulse with many longitudinal modes Remove the background of spontaneous emission Remove SASE emission outside the spectral bandwidth of a seeded pulse Define the photon energy reaching the experiment (eliminate energy jitter) Reduce the intensity of the higher harmonics Remove the fundamental when working on the harmonics Experiments requiring HSRP SXR Beamlines : SXR Beamlines Design challenges 1st mirror distance / mirror lengths Coatings (conflicting edges) Carbon K-edge Mirror damage (what is safe?) Grating damage (effect of structure?) Transport efficiency Pulse stretch Diffraction limited focusing (quality, aperture) Photon Diagnostics : Photon Diagnostics Experiments on FELs demand a wide range of diagnostics of the photon beam Pulse energy Pulse length Pulse spectrum Timing jitter Polarisation Beam position and angle Etc Non-invasive and every pulse Photon Diagnostics : Photon Diagnostics Timing and pulse length Streak camera Over come limits of camera with single photon counting and in-camera processing Achieved 280 fs FWHM resolution Single shot, 4.25 kHz Photon Diagnostics : Photon Diagnostics Pulse spectrum Grating spectrometer On-line (minimally invasive) Pulse by pulse analysis (detector ltd) Photon energy eTOF and iTOF Central wavelength, modes, harmonics On-line, non-invasive Robust and high accuracy Photon Diagnostics : Photon Diagnostics Generation of CP in a FEL with mixed planar and helical ID’s means measuring the DOP is essential Multilayer-based Polarimetry Broad-band in SXR Full Stokes vector High accuracy, proven Slow (inherently time averaged) Needs very high quality multilayers Photon Diagnostics : Photon Diagnostics Gas-based polarimetry Angle resolved photo electron spectrometer using TOF Broad-band XUV and SXR Full Stokes vector (need coincidence for CP) Requires data base of gas yields Can be shot by shot (if good cross-section) Complicated instrument (16 TOFs) Also measures photon energy, photon flux and beam position A universal, in situ, pulse-by-pulse diagnostic Global Perspective : Global Perspective Japan Success of SCSS Test FEL &rapid progress towards SCSS operation Common themes Shot by shot diagnostics Diffraction limited focusing Polarization control Pulse duration, delay and synchronisation X-ray autocorrelator using thin Si Bragg beam splitters and channel-cut Si for delay line Spectrum analysis Crystal spectrometer Compton back-scattering from a diamond crystal Global Perspective : Global Perspective USA Stunningly rapid commissioning of LCLS Excellent performance already achieved Huge user demand Proof of the importance of FEL sources Extensive use of B4C coatings on mirrors Have seen some carbon deposits Absorber uses N2 gas and Be foils Up to 7 Torr Measure fluorescence of nitrogen See speckle from Be Gas detector compared to DESY GMD LUSI diagnostic suite for HXR experiments Global Perspective : Global Perspective Europe FLASH II Huge over-subscription of FLASH has to be addressed Complementary to FLASH Seeding to go beyond the limits of FLASH SASE Timing stability Frequency stability Single mode Polarisation control Details still being worked out Global Perspective : Global Perspective EuroFEL Preparatory phase now been running for 2 years Created a vibrant community of experts with A diverse range of expertise But a common interest in delivering photons from a FEL source to a users experiment Outcomes Exchange ideas, experiences and knowledge R & D collaborations Faster solutions to common problems Is it useful? I invite you to draw your own conclusion: This meeting has demonstrated Global interest in FEL sources and common problems that face all the sources Does anyone think they can solve every problem on their own? Open Forum : Open Forum “gardener’s question time” Closing Remarks : Closing Remarks Thanks to the organisers Thanks to the speakers Thanks to all the participants for making the meeting a success Reminder to submit your papers You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
mark roper talk aSGuest53076 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 38 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: July 06, 2010 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... By: Raghavendra548 (13 month(s) ago) http://www.chennaiblossoms.com It is easy to send flowers to Chennai, Gifts to Chennai, Birthday gifts to Chennai, Gifts to Chennai from US, Gifts to Chennai India, Flowers to Chennai India through us. Saving..... Post Reply Close Saving..... Edit Comment Close By: airiaito (22 month(s) ago) http://www.japanonlineflorist.com Order online to send flowers to Japan, Flowers to Japan, Cakes to Japan. You can also send flowers and cakes to Japan for different occasions like Birthday, Anniversary , wedding etc. on any desired date or on same day. We have cheap flowers to select from to send flowers to Japan Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Photon Beamlines and Diagnostics 2010 : Photon Beamlines and Diagnostics 2010 Meeting Summary Optics : Optics To preserve the coherent wavefront of the FEL pulse To achieve diffraction limited focii Limit or control the phase error Need nm level height errors Metrology «» Manufacturing Manufacturer and end-user collaboration Classical polishing Spheres with <0.2 µrad slope errors Deterministic figuring IBF, EEM Large substrates Fast figuring - ELID Fast metrology - stitching interferometry for 2-D maps Optics “beyond the mirror” : Optics “beyond the mirror” Diamond optics for use in an X-Ray cavity FEL Need “perfect” crystals 4 needed for tunable FEL Demonstrated the required 99% reflectivity is achievable Feedback control to stabilise angle also proven Cryo cooling to reduce heat deformation Proven technologies, no reason XFELO should not work Optics “beyond the mirror” : Optics “beyond the mirror” Multilayers Large NA in the hard X-ray Improved reflectivity More convenient geometry Delay lines Smaller optics Spectral filtering (isolate harmonic) Beam splitters BW match to FEL pulse Damage (Mo:Si) Thermal in nature - diffusion Use experience with EUV lithography Optics / Metrology : Optics / Metrology There is a limit to what can be made by direct figuring Change the shape with a bender Allow more extreme shapes Allow change in focal length Be clever when setting up the bender Measure response function of each actuator - derive response matrix Can work out which actuator to use to correct residual errors, shift FL etc. Saves a lot of time! Accuracy depends on quality of original measurements More accurate metrology, lower systematic errors Optics / Metrology : Optics / Metrology Why stop at just defining the basic mirror shape with a bender? Add actuators along mirror surface to give control to smaller spatial frequencies Deterministic control Find response matrix with metrology Dial in required figure More degrees of freedom = better figure accuracy Adaptive control Phase compensator Deform mirror to correct for errors in a downstream mirror In situ interferometry Metrology : Metrology Profilers - the end-users favourite Accuracy 0.05 µrad for flats (10x improvement) Known through comparative measurements to ESAD (Deutsch national standard) 0.1 to 0.2 µrad for spheres Systematic errors more problematic Characterize with angle comparator Not the best choice for the manufacturer (too slow) Metrology / Diagnostics : Metrology / Diagnostics Hartmann wavefront sensors Developed technology for XUV and SXR Commercially available Simple Hartmann plate (no micro lenses) Calibrate with spherical wavefront from pin hole HXR more difficult - convert to optical Calibration more critical (imaging optics) and harder to achieve (can’t make spherical wavefront) Measuring beam wavefront allows determination of source properties Metrology / Diagnostics : Metrology / Diagnostics Grating interferometry At-wavelength metrology of optics with 10 nrad sensitivity Source characterisation Longitudinal position to 1 m Shot-by-shot potential Facilitated by advanced nanofabrication techniques But an instrumentally simple and robust diagnostic Photon Beam Transport : Photon Beam Transport Time preserving monochromators A diffraction grating stretches a pulse Double grating systems Complete reversal of pulse stretch Complicated, reduced efficiency Conical diffraction Pulse stretch down to few fs The only practical single grating solution in VUV to XUV Working example on HHG source (RAL) Classical diffraction mount (match to FEL source in SXR) Also few fs pulse stretch Conceptual only Needs model of FEL source >~250 eV only Photon Beam Transport : Photon Beam Transport Multi-beam experiments (TIMER) Beam splitters Wavefront (knife-edged mirror) Harmonic (multilayers) Delay lines Multilayer Multiple mirrors to vary angles Three beams coincident in time and space at the experiment, with defined angles and energies Photon Beam Transport : Photon Beam Transport HHG Seeding Essential for single mode SXR FELs (?) Successful demonstration at SCSS Test FEL and SPARC As demanding as a user beamline Focus and spatial overlap with electron beam Steering and focusing mirrors Temporal overlap Diagnostics Spectrometer, position & angle SXR Beamlines : SXR Beamlines Use with a FEL source Reduce the bandwidth of a SASE pulse with many longitudinal modes Remove the background of spontaneous emission Remove SASE emission outside the spectral bandwidth of a seeded pulse Define the photon energy reaching the experiment (eliminate energy jitter) Reduce the intensity of the higher harmonics Remove the fundamental when working on the harmonics Experiments requiring HSRP SXR Beamlines : SXR Beamlines Design challenges 1st mirror distance / mirror lengths Coatings (conflicting edges) Carbon K-edge Mirror damage (what is safe?) Grating damage (effect of structure?) Transport efficiency Pulse stretch Diffraction limited focusing (quality, aperture) Photon Diagnostics : Photon Diagnostics Experiments on FELs demand a wide range of diagnostics of the photon beam Pulse energy Pulse length Pulse spectrum Timing jitter Polarisation Beam position and angle Etc Non-invasive and every pulse Photon Diagnostics : Photon Diagnostics Timing and pulse length Streak camera Over come limits of camera with single photon counting and in-camera processing Achieved 280 fs FWHM resolution Single shot, 4.25 kHz Photon Diagnostics : Photon Diagnostics Pulse spectrum Grating spectrometer On-line (minimally invasive) Pulse by pulse analysis (detector ltd) Photon energy eTOF and iTOF Central wavelength, modes, harmonics On-line, non-invasive Robust and high accuracy Photon Diagnostics : Photon Diagnostics Generation of CP in a FEL with mixed planar and helical ID’s means measuring the DOP is essential Multilayer-based Polarimetry Broad-band in SXR Full Stokes vector High accuracy, proven Slow (inherently time averaged) Needs very high quality multilayers Photon Diagnostics : Photon Diagnostics Gas-based polarimetry Angle resolved photo electron spectrometer using TOF Broad-band XUV and SXR Full Stokes vector (need coincidence for CP) Requires data base of gas yields Can be shot by shot (if good cross-section) Complicated instrument (16 TOFs) Also measures photon energy, photon flux and beam position A universal, in situ, pulse-by-pulse diagnostic Global Perspective : Global Perspective Japan Success of SCSS Test FEL &rapid progress towards SCSS operation Common themes Shot by shot diagnostics Diffraction limited focusing Polarization control Pulse duration, delay and synchronisation X-ray autocorrelator using thin Si Bragg beam splitters and channel-cut Si for delay line Spectrum analysis Crystal spectrometer Compton back-scattering from a diamond crystal Global Perspective : Global Perspective USA Stunningly rapid commissioning of LCLS Excellent performance already achieved Huge user demand Proof of the importance of FEL sources Extensive use of B4C coatings on mirrors Have seen some carbon deposits Absorber uses N2 gas and Be foils Up to 7 Torr Measure fluorescence of nitrogen See speckle from Be Gas detector compared to DESY GMD LUSI diagnostic suite for HXR experiments Global Perspective : Global Perspective Europe FLASH II Huge over-subscription of FLASH has to be addressed Complementary to FLASH Seeding to go beyond the limits of FLASH SASE Timing stability Frequency stability Single mode Polarisation control Details still being worked out Global Perspective : Global Perspective EuroFEL Preparatory phase now been running for 2 years Created a vibrant community of experts with A diverse range of expertise But a common interest in delivering photons from a FEL source to a users experiment Outcomes Exchange ideas, experiences and knowledge R & D collaborations Faster solutions to common problems Is it useful? I invite you to draw your own conclusion: This meeting has demonstrated Global interest in FEL sources and common problems that face all the sources Does anyone think they can solve every problem on their own? Open Forum : Open Forum “gardener’s question time” Closing Remarks : Closing Remarks Thanks to the organisers Thanks to the speakers Thanks to all the participants for making the meeting a success Reminder to submit your papers