The BESSY wiggler/undulator-TGM-5 beamline

In actual performance, the 35 pole wiggler/undulator (W/U) at BESSY has been shown to deliver 50 to 250 times more flux than a TGM with 10 mrad of dipole radiation under otherwise comparable conditions. The beamline, laid out for photon energies from 15 to 400 eV, has been calibrated and the resolution measured at several energies. Interactions of the W/U with the storage ring have been studied and, in part, corrected for: the working point does not change in either direction (<10%) as the gap is varied and the electron beam position in the ring remains constant to within 10 μm and the angle of emission of the SR from the ring to within 5 μrad for K≤2.7. The reduction of the lifetime of the electron beam in the ring and the change in the vertical size of the beam as a function of the gap are typical of the problems associated with the interaction of such a device on a high brightness ring. The beamline has been in normal user operation for over a year