What sealed sources are used in XRF analyzers?

Prepare for the Pennsylvania Lead Inspector Test. Study with flashcards and multiple choice questions, each question offers hints and explanations. Get ready to pass your exam!

Multiple Choice

What sealed sources are used in XRF analyzers?

XRF analyzers rely on a sealed radioactive source to provide the photons that excite the sample and cause it to emit its characteristic X-rays. The most common sealed sources for this purpose are cobalt-57 or cadmium-109, because they emit photons at energies around 14 keV (Co-57) and 22 keV (Cd-109) that efficiently ionize inner shells across many elements while keeping shielding and safety manageable. This makes it practical for compact, portable XRF devices to operate without external power for excitation. Other isotopes listed would be less suitable: some emit alpha particles or high-energy gamma rays that aren’t ideal for efficient XRF excitation, or they pose greater safety and regulatory challenges, so they aren’t used for standard XRF excitation.

XRF analyzers rely on a sealed radioactive source to provide the photons that excite the sample and cause it to emit its characteristic X-rays. The most common sealed sources for this purpose are cobalt-57 or cadmium-109, because they emit photons at energies around 14 keV (Co-57) and 22 keV (Cd-109) that efficiently ionize inner shells across many elements while keeping shielding and safety manageable. This makes it practical for compact, portable XRF devices to operate without external power for excitation. Other isotopes listed would be less suitable: some emit alpha particles or high-energy gamma rays that aren’t ideal for efficient XRF excitation, or they pose greater safety and regulatory challenges, so they aren’t used for standard XRF excitation.

More practice questions