FAR-TECH, Inc. provides precision “balanced x-ray filter pairs” utilizing a computerized design. A pair of slightly different filters, if balanced properly, can isolate spectra in a narrow energy band. This idea is demonstrated in the figures below.

FAR-TECH has a track record of designing/delivering high-quality balanced-ray filters. These filters have been utilized at the Arnold engineering center in Tullahoma, TN; for impurity trace profile studies in the DIII-D tokamak (a National Fusion Facility); and for a fusion experiment at the University of Wisconsin.

Above: a schematic layout of “quasi” mono-energetic beam spectra measurements by taking a difference of the two images of the same region.
Below: the principle concept of creating a spectrum by the beams in the “energy pass band” by taking the difference of the two images using a filter pair. The challenge is to balance the response function away from the energy pass band, in particular in the high energy region.