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 carried out by irradiating the sample surface with 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 flight model of APXS has been delivered to URSC on 6th December, 2017, for chandrayaan-2 missions.