Mirror Metrology and Development Strategy

1. Mirror Metrology and Development Strategy Q. Shen, K. Kaznatcheev, A. Fluerasu Experimental Facilities Division NSLS-II Experimental Facilities Advisory Committee Meeting April 23-24, 2009

2. Outline • Mirror requirements at NSLS-II beamlines • NSLS-II strategy for mirror development and metrology • Optical metrology laboratory • Coherence preserving optics R&D • Summary

3. Mirrors Requirements at NSLS-II beamlines CHX IXS <150 nrad <100 nrad <0.17 mrad SRX CSX <0.2 mrad • General requirements: < 0.1 mrad ~ 1 nm / 1 cm

4. Experimental Facilities R&D Areas & Budgets

5. Recruitment of Optical Metrology Expert

6. Trend in Mirror Fabrication Courtesy of A. Rommeveaux, R. Barret, ESRF • Steady improvement of the mirror quality, but not yet to 100nrad / 1nm level • New fabrication technologies emerged: APS (profile coating); Osaka/Spring-8 (plasma chemical vaporization machining (PCVM) elastic emission machining (EEM)‏; WinLight/ESRF (polishing of deformed surfaces); SESO (Bimorph, piezo embedded)‏ • New fabrication/polishing tools often require extensive use of in-house optical metrology to allow iterations in the process.

7. Mirror Development Strategy #1 500nm -1000nm • Develop NSLS-II metrology tools‏ • Use our own metrology to characterize vendor product – crucial for verification & acceptance • Leverage our state-of-the-art metrology capability to energize and attract developers and vendors • At-wavelength metrology: at existing sources, emphasis on coherence preservation QED test sample (2008): flat Si Takacs & Siddons (BNL) before: 236nm (rms)‏  Residual texture due to the tool marks-> need to reduce roughness (to 1/10) at low spatial frequencies after MRF: 10nm (rms)‏ BUT x 20 improvement

8. Optical Metrology Laboratory • NSLS-II Optical Metrology Lab plans to house/develop cutting-edge metrology tools for advanced optics development: • Fizeau interferometer • Long Trace Profiler (LTP) • Micro-stitching interferometer • Atomic Force Microscope (AFM) • At wavelength metrology ALS: flat mirror (InSync) measurements

9. OM: First Set of Instruments Specification ZYGO VeriFire : Aperture Size 4 in. (102 mm) Zoom Range 1X-6X continuous zoom Pupil Focus Range -800 mm/ +1600 mm Repeatability of Three-Flat Test λ/300 (2σ)~2nm Repeatability of rms λ/10,000 (2σ)~0.06nm Spatial Sampling1K x 1K pixel camera Surface Height Resolution Better than λ/8,000 ~0.1nm Reference Optics: Dynaflex (high reflectivity) 4” flat l/20 accuracy 4% transmission l/50 accuracy matching cavity Backreflection corner cube Status: installed FollowUp: development of precise stage (meridional direction, 50nrad) for stitching measurement of curved surfaces Specification: Motorized Tip/Tilt/X/Y with ±4° 300/300mm Vibration Isolation Table Objectives 2.5X, 20X (5 to 0.2mm FoV) Lateral Res. 0.5 μm Vertical Scan Range (PZT) 150 μm Vertical Res. < 0.1 nm RMS Repeatability < 0.01 nm Status: NewView 6300 was upgraded with 300mm XY motorized stages to perform stitching interferometry

10. Next Generation LTP Development Takacs, P.Z., Qian, S., (BNL): LTP-I; 1987 LTP-II: CRADA with Continental Optics, R&D award 1993 Pentaprizm based LTP: 1995; In-situ mLTP: by 2005 about ~10 in all major SR centers Currently aproches 0.35urad performance Participants of Advanced Optical Systems and Metrology for High Power and Coherent Beam Lines Workshop during NSLS 2004 user meeting Goal: to reach 100 nrad accuracy for large radius SR mirrors (+/-10mrad) Qian, OptEngineering 2007 > In house + international expert advisory team for LTP development

11. Optics Testing at SR B-fiber ID6 undulator DCM Si-111 HR X-ray CCD-camera Test Optics Direct beam Multilayer • Coherence preservation by multilayers • O. Tchoubar, A. Snigirev, A. Fluerasu et al. Theoretical work on phase retrieval from in-line holograms. Aim: retrieve the surface profile, power spectral density function • Experimental work at ESRF ID6 (but also get R&D NSLS x16 beamline operational) • Mirror Fabrication/ Multilayer Deposition: R.Conley

12. Mirror Development Strategy #2 • Work/Collaborate with potential vendors • Survey vendors and their current state-of-the-art technologies, organize on-site presentations and discussions, ... (QED visit Feb.2009, InSync Apr.2009, Zeiss- May) • Spell out NSLSII requirements • Seek potential collaborations, leverage NSLSII state of the art metrology and x-ray testing capability to energize and attract developers and vendors: aimed at improving their technologies towards reaching our goals • Proceed with tests and development Goal: identify 2-3 reliable vendors by mid-FY11 for procurements of NSLS-II mirrors to spec and on schedule • Long-term vision • Aimed at developing novel polishing techniques (not only with vendors, but university..), advanced metrology tools and new approach to state of the art x-ray optics (R&D adaptive optics, mirror cryo-cooling, novel optics (diamond CRL)) • Establish a regional center for advanced mirror technology, involving BNL, upstate research universities, and regional optics manufacturers and vendors

13. Summary • NSLS-II plan for mirror metrology and mirror development is in place and being executed • Recruitment is on-going for an optical metrology expert to lead the effort • Optical metrology laboratory is being established as part of experimental facilities R&D program • Metrology instruments are being procured and some have already been installed and ready for use • Remaining key instrument is the next generation LTP that is planned to be developed in the coming year • Strategy on working with potential vendors is in place • Goal: to identify and qualify 2-3 reliable vendors by mid-FY11 so that NSLS-II mirror procurement can proceed at spec and on schedule