Alpha Particle X-Ray Spectrometer
The Alpha Particle X-Ray Spectrometer (APXS) measures the abundance of chemical elements in rocks and soils. The APXS is placed in contact with rock and soil samples, exposing them to alpha particles and X-rays emitted by the radioactive decay of the curium sources. The X-ray counts and energies measured by the APXS detector enable scientists to identify all important rock-forming elements, from sodium to heavier elements. This is an improved design compared to the APXS instruments on Spirit and Opportunity, requiring a shorter amount of time to take a measurement.