Development of a portable grazing exit X-ray fluorescence system using a gold anode X-ray tube

摘要

A portable grazing exit X-ray fluorescence system (GE-XRF) composed of a low power X-ray tube (gold anode), a SiPIN detector, quartz reflector and an XY table plus rotary stage for positioning the reflector in grazing exit condition was developed in this work. The accuracy of the system was checked using a certified bovine liver sample (SRM 1577b, NIST). The relative errors between measured and certified values ranged from 2 to 22%, except P (39%) and S (26%). The absolute detection limits obtained with the portable system were in the range of 4-300 ng (15 <= Z <= 30). The portable GE-XRF system developed does not favor the detection of light elements since absorption effects were more critical (sample-to-detector distance similar to 35 mm). Besides that, it was operated under room temperature and atmospheric pressure, 20 degrees C and 1.0 atm, respectively. The quantitative results of a multielement reference sample were compared with the results of a GI-XRF system. Both techniques were compatible and presented good accuracy with reference values. The portable GE-XRF system developed in this work was efficient, showing that it is possible to produce a grazing exit X-ray fluorescence system using a low power X-ray tube, a Si -PIN detector and quartz reflector.