Alpha Particle X-ray Spectrometer

APXS instrument measures the elemental composition (Na, Mg, Al, Si, K, Ca, Ti, Fe) of the Lunar soil and rocks around the lunar landing site. This is done by irradiating the sample surface with an Alpha source (244Cm – Alpha particles: 5.8 MeV and X-rays: 14.3 keV, 18.4 keV) and measuring the X-ray fluorescence spectrum. APXS instrument provides energy resolution of ~140 eV @ 5.9 keV. The APXS flight model was delivered to URSC on 6th December 2017 for Chandrayaan-2 mission.