Source Parameters

 

  • X-ray source: APS undulator A, 72 periods, period length 33mm, provides continuous energy coverage from ~3keV to (theoretically) well above 100keV.
  • Electron beam size (σ values): 270μm horizontal, 8.6μm vertical.
  • Electron beam divergence (σ values): 11.4μr horizontal, 2.9μr vertical.
    • Note: The X-ray source dimensions are somewhat larger than the values above, due to radiative effects. The extent of the radiative “bloat” depends on x-ray energy, becoming negligible for high energies.
  • Bruker cryogenically cooled double crystal monochromator, using pairs of Si (111) or Si (311) crystals.
  • Energy range : 5-36keV with Si (111), 10-70keV with Si(311)
  • Bandwidth: 1.3x10-4 with Si (111), 2.8x10-5 with Si (311)
  • Bruker mirror system, consisting of vertically focusing bimorph mirror and vertically deflecting flat silicon mirror. Coated with 3 stripes, as follows:
    • SiO2 – energies below 12 keV
    • Rh – energies between 12-23 keV
    • Pt – energies above 23 keV

 

Contact

Yu-Sheng Chen
Advanced Crystallography
(630) 252-0471
yschen@cars.uchicago.edu

Mati Meron
Beamline Optics
(630) 252-0468
meron@cars.uchicago.edu

Wei Bu 
Liquid Surfaces/Interference
(630) 252-0470
bu@cars.uchicago.edu

Theoretical Flux T​hrough The Working Aperture:

 

Photon Energy (keV)

Harmonic

Flux (phot/sec/0.1%BW)

10

1

4x1014

30

3

5x1013

50

5

7x1012

70

7

1x1012