Figure 5
Measured spectra of the fundamental harmonic (a) and the third harmonic (b) spontaneous emission at the resonant wavelength of ∼870 nm in a single-bunch operation. The undulator gaps were 123 mm (K = 2.08) in (a) and 87 mm (K = 4.14) in (b). The dispersive gaps were 140 mm in (a) and 120 mm in (b). |