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Please note:  wafer level TXRF measurements are no longer available, details on TXRF Home Page.

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Incident energy tuning is done with a double multilayer monochromator.  Since the multilayers have a constant d-spacing, it is possible to adjust the incident energy by varying the angle as given by Bragg's law.  While the multilayers work in a similar fashion as crystal monochromators, a higher band pass is achieved since the d-spacing is much larger than most crystals.  Finally, by using two multilayers in series it was possible to reduce the reflectivity at lower energies thereby removing unwanted background signal.

Reflectivity curves are shown below for a Bragg angle of .12 degrees for both a single and double multilayer.  It should be noted that a double multilayer setup does not remove x-rays at energies below 4 keV, necessitating the need for a 1mm graphite filter.

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Last modified: January 26, 2007