• Kachel, T.; Eggenstein, F.; Follath, R.: A soft X-ray plane-grating monochromator optimized for elliptical dipole radiation from modern sources. Journal of Synchrotron Radiation 22 (2015), p. 1301-1305

10.1107/S1600577515010826
Open Access Version

Abstract:
Abstract We describe a new but yet well proven way of making elliptically polarized dipole radiation from the BESSY II storage ring applicable to the SX700-type collimated plane grating monochromator PM3. We show that due to the limited vertical acceptance of the grating a simple use of vertical apertures is not possible in this case. Rather, deflecting the beam up- or downwards by rotating the vertically collimating toroidal mirror M1 around the light axis leads to an excellent performance. The resulting detune of the photon energy can be taken into account by a readjustment of the monochromator internal plane mirror M2. The energy resolution of the beamline is not affected by the non-zero “roll” of the collimating mirror.