Energy-dispersive X-ray fluorescence analysis of highly radioactive samples with small tubes and pyrographite crystals

Energy dispersive x-ray spectrometry

“…Although this is a reasonable way of summarising overall improvements in both detector fabrication techniques and electronic noise, the graph with time [28] shows signs of an asymptotic approach to a fwhm only slightly below 140 eV which might suggest that significant improvements in spectrometer performance are unlikely. At 5.9 keV, the separation of Ka peaks is roughly 500 eV (figure 11) so indeed, there is little to be gained by improving the resolution at 5.9 keV (unless, of course, it could be reduced sufficiently to allow Kp/Ka overlaps to be resolved).…”

“…Typically the 14.4 keV y-ray frn s7Co, or Sr K x-rays from an 8 8 Y source, is used to measure deadlayers above about 3000 A thick in Ge detectors. -The deadlayer thickness XGe is then estimated from the formula XGe = 2 (K)(J) (3) IK wK Cy CK where (CK/CY) is the observed ratio of Ge K x-rays and the exciting y-rays, (s./K) is the ratio of intrinsic detector efficiencies for the exciting y-ray and Ge K x-rays, pK is the mean K-shell attenuation coefficient in Ge for the exciting y-rays, and wK = 0.55 for germanium [28]. [29] which will be useful for estimating the absorption of x-rays in silicon, germanium, and other low-Z elements.…”

“…Thicker deadlayers may be estimated purely with photons. However, even with low energy photons, such as 3 keV, the low value of the silicon K-shell fluorescence yield [28] (wK u 0.045) does not permit convenient measurement of silicon deadlayers thinner than about 10,000 A (1 pm), whereas typical deadlayers are currently less than 100 R (0.01 pm) thick [27].…”