A soft X-ray plane-grating monochromator optimized for elliptical dipole radiation from modern sources

Abstract

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 planegrating monochromator PM3 is described. It is shown 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 upwards or downwards by rotating the vertically collimating toroidal mirror M1 around the light axis leads to excellent performance. The resulting detuning 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 nonzero 'roll' of the collimating mirror.

Magnetization compensation and spin reorientation transition in ferrimagnetic DyCo5 : Multiscale modeling and element-specific measurements

“…The element-specific hysteresis loops were recorded by setting the photon energy at the desired absorption edge (Dy M 5 or Co L 3 ) and measuring the transmitted intensity, while sweeping the magnetic field oriented perpendicular to the sample plane. The XMCD experiments at low temperatures and high magnetic fields were performed at the UE46-PGM1 beam line of HZB-BESSY II synchrotron, while the high-temperature experiments (T > 200 K) were done using the ALICE diffractometer [38] installed at the PM3 [39] beam line of the same light source.…”

Structural and magnetic characterization of large area, free-standing thin films of magnetic ion intercalated dichalcogenides Mn0.25TaS2and Fe0.25TaS2

“…We used γ ≈ .925 which is characteristic for the off-axis emission of the bend magnet radiation at beamline PM3 (specifically at the Fe L edge) [31]. A cursory comparison between the XMCD spectra for the two materials unveils a notable difference, namely, the integrated intensity of the L 3,2 edges are vastly different.…”

The at-wavelength metrology facility for UV- and XUV-reflection and diffraction optics at BESSY-II

“…Thus the polarization can be changed from horizontal linear polarization (S1 = +1) to elliptical polarization with a selectable degree of circular polarization (S3 AE0.8). This is done by an azimuthal rotation of the pre-mirror M1 accompanied by an equal but opposite correction of incidence angle of the monochromator mirror M2 (Kachel et al, 2015). Thus the incidence angle on photondiag2015 workshop the grating is unaffected by this operation and no energy shift is encountered during change of polarization.…”

“…Assuming no unpolarized background, the circular polarization is determined by P circ = ½ð1 À P 2 lin Þ 1=2 . The beamline will be established for optional use of elliptically polarized offplane radiation soon according to the polarization steering techniques described by Kachel et al (2015).…”