Figure 2
(a) Schematic diagram of the nested 4B-HRM. It consists of two artificial channel-cuts: Si(111) with asymmetry angles α1 = −25° and α4 = −α1, and Al2O3(110) (α2 = 60°, α3 = −α2). The first (silicon) reflection collimates the beam while the second (sapphire) selects the energy. The remaining crystals return the beam back to its original size and direction. (b) Simulated spectral reflectivity curve of the HRM showing an efficiency of 4.8%. (c) Comparison between the experimental rocking curve of crystal number 4 and simulations. (d) Calculated phase space of the photons exiting the HRM showing a well collimated beam with a 30 meV energy bandwidth. |