X-ray monochromators and electron probe micro-analysis (EPMA) systems using such monochromators are disclosed. A turretless x-ray monochromator may have a cassette of reflectors instead of a turret. The cassette stores a plurality of reflectors that can be inserted into a conventional Rowland circle monochromator geometry. A transfer mechanism selectively moves reflectors from the cassette to a reflector positioner. The use of the cassette allows each reflector to be placed closer to a source of x-rays, thereby allowing a larger solid angle for x-ray collection. An alternative x-ray monochromator uses a non-focusing reflector that can be fixed, scanned axially or scanned radially to provide large solid angle detection of x-rays at various energies with a single reflector.