Figure 3
Trajectories of the U-49 undulator at various gaps. The upstream endpole is compensated over the entire gap range with compensation currents of | I | ≤ 64 amp-turns. The coil of the downstream endpole is not powered. Gap = (a) 15, (b) 17, (c) 20, (d) 24, (e) 30, ( f ) 38 and (g) 50 mm. |