MONOCHROMATOR-INDUCED GLITCHES IN EXAFS DATA .2. TEST OF THE MODEL FOR A PINHOLE SAMPLE

Monochromator-induced glitches in the extended X-ray absorption fine s tructure (EXAFS) are studied using a pinhole sample. We have collected more detailed beam-profile data that enabled us to do a better simula tion of the glitch shape. Applying the model we developed earlier, we obtain excellent agreement between the simulation and the experimental pinhole glitch. We point out that the EXAFS glitch is not caused by t he crystal glitch alone, but is induced by the vertical movement of th e glitch in space across the beam, as the energy is changed when the s ample is non-uniform. Several methods have been suggested to minimize the glitch amplitude. Here we note that glitches can be reduced using two double-monochromators or a pair of strip array detectors for the i ncident and transmitted beams.