Figure 4
APS undulator A spectra with the undulator gap set to 18.00 mm. The solid line is the measured spectrum after reflection from the Si portion of the mirror, the dashed line is the measured spectrum reflected from the Pt-coated portion of the mirror, and the dot-dashed line is the predicted white-beam spectrum. The measured full-width-at-half-maximum energy bandwidth of the first harmonic is ΔE/E = 0.026. |