Double phase-plate setup for chromatic aberration compensation for resonant x-ray diffraction experiments

Abstract

An x-ray phase plate that can generate arbitrary states of linearly polarized x-rays is an indispensable device in recent resonant x-ray diffraction experiments. A thick phase plate, which is necessary to produce a high degree of linear polarization, however, considerably reduces incident x-ray intensity, particularly for low energy x-rays. Degradation of linear polarization chiefly arises from the finite energy width of incident x-rays in recent synchrotron sources, and hence we have equipped a double phase-plate setup for chromatic aberration compensation using two thin phase plates. The total linear polarization 90.5% for a single phase plate of 0.5 mm thickness was remarkably improved to 96.8% by using two phase plates of about 0.3 mm thickness at 6.1236 keV; a high degree of linear polarization was achieved without additional loss of intensity.