Fast tomography using quasi-monochromatic undulator radiation

A beamline with a helical undulator has been used without a monochromator for fast high-resolution tomographic imaging with an X-ray energy of 12.4-16.5 keV and an energy bandwidth of 2-3%. The X-ray beam was expanded with two mirrors to 12 mm × 4 mm. The X-ray field was made uniform by a diffuser. The detector pixel size was 9.9 µm × 9.9 µm. At the highest speed, a 180° scan was completed in 6 s with 454 projections. Beam-hardening effects were not significant. This technique may be useful in studying time-dependent structural changes of soft materials such as polymers and biological samples.