Table 2. Source flux.

	Theoretical undulator flux [photons pulse−1  (1% bandwidth)−1] 1.2 mm × 4 mm aperture at distance d		Measured flux [photons pulse−1  (1% bandwidth)−1] 1.2 mm × 4 mm aperture at 30 m
	Long-period undulator at 22 mm gap, d = 30 m	In-vacuum undulator at 2.5 mm gap, d = 17 m	Measured for long-period undulator. From Fig. 2 ▸, compensated for Parylene C filter and multi-layer mirror monochromator transmission
2 keV	3.5 × 105 at K = 1.7	6 × 107 at K = 1.9	4 × 105
4 keV	1.2 × 105 at K = 1.7	4 × 107 at K = 0.9	1 × 105
6 keV	5.7 × 104 at K = 2.7	2.1 × 107 at K = 1.9	5 × 104
8 keV	4.0 × 104 at K = 2.7	1.3 × 107 at K = 1.5	3 × 104
10 keV	2.5 × 104 at K = 2.7	1.1 × 107 at K = 1.2	2 × 104
15 keV		6 × 106 at K = 2.0
20 keV		4 × 106 at K = 2.1