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![[Figure 5]](rv5132fig5mag.jpg)
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Figure 5
Calculated and measured flux at the sample as a function of energy at 200 mA for different mirror coatings (Si, Rh, Pt) without beam-defining aperture. The calculated flux curves are based on simulations using MASH (Sondhauss, 2014  ) and assumes an undulator specification of Kmax = 1.92 while the measured flux curves used a conservative Kmax of 1.8 (corresponding to 5 mm gap while the closed gap of 4.2 mm gives Kmax = 2.19). The step increase at certain energies is due to the change of undulator harmonic and thus differs between calculated and measured curves. The flux curves drop rapidly above certain energies that corresponds to the mirror cut-off energies. In the ray-tracing the cut-off energy for the Rh coating is underestimated because the density is assumed to be 85% of the bulk density, whilst the actual density appears closer to 100%. The flux was measured using a PIN photodiode (AXUV100G, EQ Photonics GmbH) mounted on the detector 200 mm downstream of the sample position. Both calculated and measured flux are normalized to 200 mA storage ring current and includes the full flux at the sample (without any beam defining aperture or filters). The Pt-coated area was not measured and is not yet in normal user operation. |
![[Figure 5]](rv5132fig5.jpg)
 | JOURNAL OF SYNCHROTRON RADIATION |
ISSN: 1600-5775
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