Mirror Metrology and Development Strategy Q Shen K

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 BROOKHAVEN SCIENCE 1

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

Mirrors Requirements at NSLS-II beamlines CHX IXS <100 nrad <150 nrad <0. 17 mrad SRX CSX <0. 2 mrad • General requirements: 3 < 0. 1 mrad ~ 1 nm / 1 cm BROOKHAVEN SCIENCE

Experimental Facilities R&D Areas & Budgets 4 BROOKHAVEN SCIENCE

Recruitment of Optical Metrology Expert 5 BROOKHAVEN SCIENCE

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

Mirror Development Strategy #1 • Develop NSLS-II metrology tools • • • 500 nm 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 before: 236 nm (rms) after MRF: 10 nm (rms) -1000 nm Takacs & Siddons (BNL) Residual texture due to the tool marks-> need to reduce roughness (to 1/10) at low spatial frequencies BUT x 20 improvement 7 BROOKHAVEN SCIENCE

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 (In. Sync) measurements 8 BROOKHAVEN SCIENCE

OM: First Set of Instruments Specification ZYGO Veri. Fire : Status: installed Aperture Size 4 in. (102 mm) Follow. Up: Zoom Range 1 X-6 X continuous zoom development of precise Pupil Focus Range -800 mm/ +1600 mm stage (meridional Repeatability of Three-Flat Test λ/300 (2σ)~2 nm direction, 50 nrad) for Repeatability of rms λ/10, 000 (2σ)~0. 06 nm stitching measurement Spatial Sampling 1 K x 1 K pixel camera of curved surfaces Surface Height Resolution Better than λ/8, 000 ~0. 1 nm Reference Optics: Dynaflex (high reflectivity) 4” flat l/20 accuracy 4% transmission l/50 accuracy matching cavity Backreflection corner cube Specification: Status: New. View Motorized Tip/Tilt/X/Y with ± 4° 300/300 mm was 6300 Vibration Isolation Table upgraded with Objectives 2. 5 X, 20 X (5 to 0. 2 mm Fo. V) 300 mm XY Lateral Res. 0. 5 μm motorized stages Vertical Scan Range (PZT) 150 μm to perform stitching Vertical Res. < 0. 1 nm interferometry RMS Repeatability < 0. 01 nm 9 BROOKHAVEN SCIENCE

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 m. LTP: by 2005 about ~10 in all major SR centers Currently aproches 0. 35 urad 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 (+/10 mrad) Qian, Opt. Engineering 2007 > In house + international expert advisory team for LTP development 10 BROOKHAVEN SCIENCE

Optics Testing at SR ID 6 undulator B-fiber DCM Si-111 Test Optics Direct beam • HR X-ray CCD-camera 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 ID 6 (but also get R&D NSLS x 16 beamline operational) Mirror Fabrication/ Multilayer Deposition: R. Conley 11 BROOKHAVEN SCIENCE

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, In. Sync 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-FY 11 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 BROOKHAVEN SCIENCE 12

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. FY 11 so that NSLS-II mirror procurement can proceed at spec and on schedule 13 BROOKHAVEN SCIENCE