1 BROOKHAVEN SCIENCE ASSOCIATES Vibrations effect on 1nm focussing K. Evans-Lutterodt NSLS-II VTG Januaury

2 BROOKHAVEN SCIENCE ASSOCIATES Outline Background and important optics metrics Simple optics layout How we see the source; some stability reqs More complex layout (Waveguide) Can we position with 1nm beam sufficient accuracy?

3 BROOKHAVEN SCIENCE ASSOCIATES Towards 1nm X-ray Optics Figure courtesy of C. Jacobsen Future It can be done: There is no physical reason we cannot get to 1nm However, it will take resources and a targeted effort.

4 BROOKHAVEN SCIENCE ASSOCIATES Basic Issues Metrics 1.Numerical Aperture and resolution 2.Depth of field 3.Aperture 4.Efficiency 5.Chromaticity 6.Modulation Transfer Function If resolution is 1nm => then DOF =27nm Resolution of 1nm at =1A requires NA < 0.1

5 BROOKHAVEN SCIENCE ASSOCIATES Simplest configuration Mono deleted for clarity

6 BROOKHAVEN SCIENCE ASSOCIATES Order of magnitudes for stability  ~ 10 microns(v) x 40 microns (h) Slit down in the horizontal to get 10 by 10. Demagnify by 10 4 to get 1nm. For a source to lens of 50m, this implies 5mm focal length. If you include details, we expect focal lengths of between 1 to 5mm (We would really like to get out to 100mm, but this is probably too tough, Aperture) Main point: Easy to integrate lens and sample stage monolithically.

7 BROOKHAVEN SCIENCE ASSOCIATES We already mount optics and sample monolithically

8 BROOKHAVEN SCIENCE ASSOCIATES Stability of e-beam is crucial for effective source size Position of electron beam translates directly into stability of image. Typical tolerance is 10% if e-beam size; 0.3microns?. Angular stability?  L Angular uncertainty ~ (0.3 microns/ 3 meter) ~ 1e-7 radians

9 BROOKHAVEN SCIENCE ASSOCIATES How the stability comes in B: Intensity If sigma stability is 10%, then stability adds negligibly to size If you are measuring fluorescence intensity, and we assume a gaussian profile And we want to keep signal intensities within 1%: A: Size 1% criterion 5% criterian

10 BROOKHAVEN SCIENCE ASSOCIATES Off-axis Abberrations Using zone plate as a guide: will have to revisit this in optics R&D Aberration angular field of view, , is given by Using N=1e5, F=0.1, =0.1nm   1e-3 radians which is much bigger than everything else so not a problem.

11 BROOKHAVEN SCIENCE ASSOCIATES

12 BROOKHAVEN SCIENCE ASSOCIATES More complicated optics layout

13 BROOKHAVEN SCIENCE ASSOCIATES Main advantages of waveguide geometry More stable, but more optics so more loss.( 4.7% experimental state of the art, but not optimal) Wave guide provides new source size (50nm) Allows better working distances All fluctuations in position,angle translate to intensity fluctuations Attempt to do normalization, not invented yet for small WD.

14 BROOKHAVEN SCIENCE ASSOCIATES Can we position with 1nm accuracy? It is difficult, but possible. Worry about materials, and temperature control.

15 BROOKHAVEN SCIENCE ASSOCIATES Commercial 0.02nm positioner

16 BROOKHAVEN SCIENCE ASSOCIATES Non Commercial (APS-RD) Figure Closed-loop control scheme test for a 1D setup. A series of 0.1 nm, 0.2 nm, and 0.3 nm steps is demonstrated.

17 BROOKHAVEN SCIENCE ASSOCIATES Time scale : 1second /scan. If normalization invented then stability to 1 second ok If not ~2 hour full scan stability. Timescales