| 摘要 |
<p>It is common to analyse crystalline materials using a technique that involves making an X-ray diffraction pattern from the material and comparing this with similar, reference patterns derived from known materials. There are, nevertheless, serious problems with the present implementations of the procedure; it is a destructive one, for it involves the original material sample being either cut into slices or powdered, and this means that the sample in its real form is lost forever. In addition, the technique in its present form is extremely time-consuming, mainly because the usual commercial sources of X-rays are relatively weak (with a low intensity, or brightness), monochromatic (single frequency), and of low penetrating capability. The present invention proposes using X-rays that are more brilliant, that are of a higher, more penetrating frequency, and that are polychromatic. More specifically, the invention suggests a method in which the material sample is illuminated with a collimated beam of polychromatic X-ray photons of a brightness of at least 1015 photons/sec/mrad2/0.1 % bandwidth and energies of at least 20keV. A suitable source of such X-rays is a synchrotron.</p> |
