| Fig.17. A typical groove profile derived from the AFM image of the 2400/mm replica grating. The average peak to valley groove depth is 90 Å. The blaze angles, measured from the horizontal, of the left and right facets are 3.4 deg. and 6.2 deg., respectively. |
| Fig.18. The layout of the automated efficiency checker (AEC) at Richardson Gratings (Newport Corp.) is shown. The apparatus is in a dark room and is computer operated. The grating and the scan arm can move independently to allow either monochromator mode (fixed grating deviation angle) or spectrograph mode (fixed grating incidence angle) or any other geometry (e.g. fixed wavelength, scanning incidence angle) to be measured. |
| Fig.19. The Diffraction Grating Evaluation Facility (DGEF) of the NASA GSFC Optics Branch. |
| Fig.20. The FAUST scatterometer set-up (vacuum environment configuration). Focusing mirror focal length is 1.2 m. All hardware is computer-controlled (except grating tip-tilt mount). |
| Fig.21. The NRL beamline X24C attached to the NSLS X-ray ring. |
| Fig.22. The synchrotron radiation is dispersed by a monochromator that has a resolving power up to 1000 and 108 to 1012 photons/sec/0.1% bandpass peaking at ~ 100 eV. Thin filters are suppressed the radiation from the monochromator in the higher harmonics. The wavelength scale is established by the geometry of the monochromator and the absorption edges of the filters. Two elements (e.g. grating and mirror) are precisely translated and rotated by computer control while maintaining fixed entrance and exit slits. Gratings are selected without breaking vacuum and cover from 1 keV through the visible. The radiation is 90% polarized with the electric field vector in the plane of the storage ring. |
| Fig.23. A photograph of the reflectometer, the photodiode chamber, and the larger instrument
calibration chamber attached to the X24C beamline.
|
| Fig.24. Efficiency of –1 order of a 2400 g/mm blazed holographic master grating computed with the average AFM groove profile of 7.0 nm depth and RI of SiO2 taken from the CXRO compilation for different calculation modes vs. wavelength. |
| Fig.25. Measured and calculated efficiency of –1 order of a 2400 g/mm blazed holographic master grating, plotted vs. wavelength. Efficiency models calculated for different groove profiles and RI of SiO2 taken from the CXRO compilation. |
| Fig.26. Measured and calculated efficiency of –1 order of a 2400 g/mm blazed holographic master grating, plotted vs. wavelength. Efficiency models calculated for scaled AFM groove profiles and RI of SiO2 taken from different sources. |
