Figure 1
(a) Calculated flux profiles of the harmonic modes (3rd to 17th) of IU24, with the parameters shown in Table 1. (b) Measured and normalized flux spectra of the 3rd and 5th harmonic modes of the undulator IU24 at gaps of 8.0 and 8.7 mm, with flux peaked at 7376 eV and 4998 eV, respectively; the data are fitted (solid curves) using the software Spectra. (c) The 4 m IU24 (right-hand side, with NEG representing for non-evaporable getter pump) comprises up and down vanadium-steel magnet poles (middle) that are sandwiched by blocks of NdFeB alloy. The gap magnet surfaces are covered with Cu-Ni sheets (left). |