1 BROOKHAVEN SCIENCE ASSOCIATES Nanopositioning R&D Plan Yong Chu Experimental Facilities Division, NSLS-II Experimental Facilities Advisory Committee

1 BROOKHAVEN SCIENCE ASSOCIATES

Nanopositioning R&D Plan

Yong ChuYong Chu

Experimental Facilities Division, NSLS-II Experimental Facilities Advisory Committee Meeting

April 23-24, 2009


HXN TeamHXN beamline

Yong Chu: Group Leader (Joined Jan. 2009)

Beamline Scientist: Getting near making decision to hire

Ken Evans-Lutterodt (MOU Staff, Kinoform development, lead initial HXN effort )

Nanopositioning R&D

Engineer: Interviewing

1 nm R&D

Hanfei Yan (MLL theory, optics testing)

Enju Lima (coherent phase retrieval, optics testing)

Ray Conley (MLL fabrication, metrology)

Nathalie Bouet (postdoc, MLL processing)

James Biancarosa (technician, MLL fabrication)


Technical Challenges

• Focusing optics- fabrication of large (>100 m), wedged MLLs- thinning MLLs for x-ray energies at 10 keV or lower- bonding two MLLs into a monolitic optic- wedged MLLs are extremely chromatic

• X-ray Microscope- sub-nanometer positioning /scanning- sub-nanometer stability - small working distance ( < 1 mm)- integrated XRF detector with maximum solid angle- implementation of in situ controls or sample environments

• End-Station- vibration, temperature, air-flow, acoustic management

• Beamline optics - large coherence length at focusing optics- angular stability of 1 rad or better- preservation of uniform wave front


Schematic of the Overall Design Strategy for 1nm

Satellite bldg. Thick concrete slab structural filtering: z < 20nm

Conventional natural site vibration: z < 25nm

Specially engineered granite support

with no vibration amplification: z<20nm

Active damping /isolation table: z~2-4nm

Low-profile low thermal expansion stages with active feedback: z~0.2nm

Temperature stability in mini-closure: T < 0.05oC overall, < 0.01oC relative (bewteen optic & sample)

Granite block

Satellite bldg. wall on separate footing

Engineered structures to compensate for measured floor vibration

Hutch wall

In-hutch T ~ 0.1oC

1nm focus


Considerations for Nanopositioning• Actuator - piezoelectric with moderate travel distance

• Guidance/Carrier - avoid bearings, sliders, screws, gear-reducer, etc

- flexure-based motion for higher stiffness.

• Sensors- feedback on the “combined” motion

Laser Doppler Linear Encoder- require low noise enabling high res.

• Control - high speed/bandwidth

- need capability for “fly scan”

• Environment- suppression of low frequency vibration- temp. stability to prevent drift

Deming Shu’s Prototype Linear Flexure 2 mm travel range + 4 rad tilt error

Resolution test of the one-dimensional laser Doppler linear actuator closed-loop control system by Deming Shu (APS)

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Nanopositioning R&D Plan In collaboration with the APS:

• Develop a long travel (~3mm), high-stiffness, flexure-based xyz linear stages with laser encoding resolution of sub-nanometer.

• Develop a long range (~10°), high-stiffness, flexure-based rotary stage. - use high mechanical repeatability to build a look-up table to correct run-out and wobble errors.

• Develop MLL positioner, meeting the HXN requirements (the experience from the CNM/APS MLL instrument will be very helpful).

• Construct a HXN prototype (in air or He) combining the above components by FY2011-Q4.

• Develop vibration damping solutions for the HXN support frame/table.


HXN microscope

• The microscope design will be guided by the experience with the HXN prototype.

• Require differential laser encoding between the sample and the MLL optics.

• In vacuum for thermal stability.

• Integration of XRF detector.

• Require 0.2~0.5 nm stability.

• Work with a vender for construction


FY2009 FY2010 FY2011 FY2012 FY2013 FY2014 FY2015HXN Time Line

Prototype-I

Experiment at CNM/APS

Wedged MLL available

Testing Prototype-I at APS or other SRs

Prototype-II Design

Experiment at HXN

Prototype-II construction

Build up NSLS-II Nanopositioning Lab:

Research Vibration Damping for the HXN table


Summary

• Nanopositioning R&D will be focused on developing high-stiffness, flexure-based xyz linear stages and a rotary stage with long travel (~3mm + ~10°) in collaboration with the APS

• HXN prototype is planned to be constructed by FY2011-Q4.• HXN prototype will enable:

- testing of MLLs- investigating methods to bond two MLLs- identifying specific engineering/technical challenges required for the HXN microscope

Documents

1 BROOKHAVEN SCIENCE ASSOCIATES Nanopositioning R&D Plan Yong Chu Experimental Facilities Division, NSLS-II Experimental Facilities Advisory Committee