X-ray fluorescence analysis
Determination of the chemical composition of fuel ash by X-ray fluorescence analysis (energy dispersive XRF of shimadzu / EDX 800-HS). The detector measures the incident characteristic X-ray radiation sample directly and the total radiation of the sample is separated into individual elements. Semiconductor detectors generate an electron pulse upon impact of the X-ray photon, where the intensity of the pulse is proportional to the energy of the incident photon. All pulses are amplified and counted in a multichannel analyzer. It consists of Si, Ge or other semiconductor material. The photons pass through a Be window into the detection chamber. On the front side of the detection chamber we have an inactive layer and at the back side an accumulation layer for the photons. The area of the signal corresponds to the concentration of the photons. Optimum measuring conditions occur at maximum intensity, lowest underground, lowest line overlay.
Advantages: No chemical extraction is necessary. Ash sample stays preserved.
Sample preparation: Mix and pestle the ash, then press with a special wax (mixture 1:5). Amount of ash required for single measurement is about 200mg.
Measuring range: Not suitable for elements lighter than boron. Reasonable results from sodium.