Broadband filtering of an X-ray spectrum by transmission through a polycapillary structure

The efficiency of broadband filtering of a polychromatic X-ray spectrum by a polycapillary structure in the region of photon energies $E>$ 10 keV was demonstrated. A polycapillary 40.5-mm-long rod made of borosilicate glass and containing 10$^6$ parallel hexagonal capillaries was used as a filter. Filtering was performed by introducing a misalignment of 0–4 mrad between the axis of this capillary structure and the primary beam direction. The relative attenuation of spectral density observed at energies ranging from 12 to 23 keV was as high as 17 dB.