Possible spectrometers Bent Bragg (after P. Siddons-NSLS) Mosaic crystal Bent Laue Zhong Zhong-NSLS X-ray Grating P. Heimann-ALS, S. Hulbert-NSLS

Bent Bragg Spectrometer Strip detector (200 strips) 76 mm surface normal Si (422) 2 mm Cu foil R=3.9 m

SPPS Cu near edge - Si (422) dispersive analyzer

Cu near edge structure (for reference)

Bent Bragg Spectrometer Strip detector (200 strips) 76 mm surface normal Si (422) 2 mm R=3.9 m

Adjust crystal asymmetry so that the Si (422) reflection width is Δθ/200 Corresponding to 200 resolution elements

Reflectivity Angle (microradians) Asymmetric Si (422) FWHM: 100 microrad 8000eV For reference θB=45; E=7908 eV ΔE/E = 1 x 10-4 Reflectivity 100 microrad Angle (microradians)

Und-pinhole distance 200 m Pinhole 2.0 x 0.02 mm2 Photon energy (keV) On axis +0.5 mm +1.0 mm

Bent Bragg to do list Simulation considering position dependent spectrum Role of jitter Test K sensitivity with simulated data (including noise)

Mosaic crystal spectrometer 180-2θ 2 x Mosaic spread 2ω

For PG (002) Δθ=0.3 deg

How far away is the detector? Divide the angular spread into 100 elements, 2Δθ / 100 = 1.0x10-4 For a 2 mm beam 20m

Andreas Freund, Anneli Munkholm, Sean Brennan, SPIE, 2856,68 (1996) 24 keV 10 keV

Mosaic crystal to do list Crystal uniformity ? Ultimate resolution ? Experimental geometry (20 m crystal to detector distance)

Grating spectrometer Phil Heimann RSI, 76, 063102 (2005)