Bend magnet beamline for scanning transmission x-ray microscopy at the Advanced Light Source

A bend magnet at the advanced light source is sufficiently bright to illuminate a scanning transmission x-ray microscope, with a zone plate lens to focus the soft x-ray beam at the diffraction limit. The beam line must be carefully optimized for this one purpose of high count-rates, of the order of 1MHz, are to be achieved in the microscope. Such a design is described. The nominal resolving power is 2000 from 150eV to 600eV using a single spherical diffraction grating. Twice the resolving power is available at reduced flux, and the intensity can be traded independently against the spatial and spectral resolution.