Which radiation sources are commonly used in XRF instruments?

X-ray fluorescence (XRF) instruments commonly employ specific radiation sources that provide the necessary energy for exciting atoms in a sample, allowing for the identification and quantification of elements based on their characteristic X-ray emissions. Cobalt-57 and Cadmium-109 are frequently used in XRF technology for several reasons.

Cobalt-57 is a gamma-emitting isotope that can produce low-energy X-rays, making it suitable for detecting elements commonly found in various materials. Cadmium-109, on the other hand, emits X-rays at specific energies that can efficiently excite a range of elements, making it a powerful source in environmental and materials analysis. Both isotopes provide reliable and consistent energy levels that enhance the accuracy of the measurements taken in XRF applications.

The other options consist of isotopes that are not typically used in XRF instruments. Uranium-238 and Plutonium-239 are primarily associated with nuclear applications and are not suitable for the elemental analysis required by XRF. Similarly, Cesium-137 and Strontium-90 emit much higher energy radiation that is not practical for the lower energy requirements of XRF. Osmium-192 and Iodine-131 are also not aligned with the functions of XRF due to their