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Alpha Particle X-ray Spectrometer (APXS)

NSSDCA ID: 2023-098A-07

Mission Name: Chandrayaan 3


The Alpha Particle X-ray Spectrometer (APXS) on the Chandrayaan 3 rover is designed to measure the elemental composition of the lunar soil and rocks at the landing site. It is a 0.7 kg system with an alpha source, 244 Cm, which irradiates the sample or surface with 5.8 MeV alpha particles and X-rays at 14.3 and 18.4 KeV. The instrument measures the resulting induced X-ray fluorescence spectrum from the sample with an energy resolution of approximately 140 eV at 5.9 keV. It can measure Na, Mg, Al, Si, K, Ca, Ti, and Fe.

Alternate Names

  • APXS
  • Chandrayaan3/AlphaParticleXraySpectrometer(APXS)

Facts in Brief

Mass: 0.7 kg

Funding Agency

  • Indian Space Research Organization (India)


  • Planetary Science: Geology and Geophysics

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
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