Alpha particle X-ray spectrometer

APXS is also an abbreviation for APache eXtenSion tool, an extension for Apache web servers.
Alpha particle X-ray spectrometer (top left), APXS at the back of the Mars Pathfinder Sojourner rover (top right), MSL Curiosity's alpha particle X-ray spectrometer, with a ruler (bottom).

An alpha particle X-ray spectrometer (APXS) is a spectrometer that analyses the chemical element composition of a sample from scattered alpha particles and fluorescent X-rays after a sample is irradiated with alpha particles and X-rays from radioactive sources.[1] This method of analysing the elemental composition of a sample is most often used on space missions, which require low weight, small size, and minimal power consumption. Other methods (e.g. mass spectrometry) are faster, and do not require the use of radioactive materials, but require larger equipment with greater power requirements. A variation is the alpha proton X-ray spectrometer, such as on the Pathfinder mission, which also detects protons.

Over the years several modified versions of this type of instrument such as APS (without X-ray spectrometer) or APXS have been flown: Surveyor 5-7,[2] Mars Pathfinder,[3] Mars 96,[4] Mars Exploration Rover,[5] Phobos,[6] Mars Science Laboratory and the Philae comet lander.[7][8] APS/APXS devices will be included on several upcoming missions including the Chandrayaan-2 lunar rover.[9]

  1. ^ Economou, T.E.; Turkevich, A.L.; Sowinski, K.P.; Patterson, J.H.; Franzgrote, E.J. (1970). "The Alpha-Scattering Technique of Chemical Analysis". Journal of Geophysical Research. 75 (32): 6514. Bibcode:1970JGR....75.6514E. doi:10.1029/JB075i032p06514.
  2. ^ Patterson, J.H.; Franzgrote, E.J.; Turkevich, A.L.; Anderson, W.A.; Economou, T.E.; Griffin, H.E.; Grotch, S.L.; Sowinski, K.P. (1969). "Alpha-scattering experiment on Surveyor 7 – Comparison with Surveyors 5 and 6". Journal of Geophysical Research. 74 (25): 6120–48. Bibcode:1969JGR....74.6120P. doi:10.1029/JB074i025p06120.
  3. ^ R. Rieder; H. Wänke; T. Economou; A. Turkevich (1997). "Determination of the chemical composition of Martian soil and rocks:The alpha proton X ray spectrometer". Journal of Geophysical Research. 102 (E2): 4027–4044. Bibcode:1997JGR...102.4027R. doi:10.1029/96JE03918.
  4. ^ Rieder, R.; Wanke, H.; Economou, T. (1997). "An Alpha Proton X-Ray Spectrometer for Mars-96 and Mars Pathfinder". American Astronomical Society. 28: 1062. Bibcode:1996DPS....28.0221R.
  5. ^ R. Rieder; R. Gellert; J. Brückner; G. Klingelhöfer; G. Dreibus; A. Yen; S. W. Squyres (2003). "The new Athena alpha particle X-ray spectrometer for the Mars Exploration Rovers". Journal of Geophysical Research. 108 (E12): 8066. Bibcode:2003JGRE..108.8066R. doi:10.1029/2003JE002150.
  6. ^ Hovestadt, D.; Andreichikov, B.; Bruckner, J.; Economou, T.; Klecker, B.; Kunneth, E.; Laeverenz, P.; Mukhin, L.; et al. (1988). "In-Situ Measurement of the Surface Composition of the Mars Moon Phobos: The Alpha-X Experiment on the Phobos Mission". Abstracts of the Lunar and Planetary Science Conference. 19: 511. Bibcode:1988LPI....19..511H.
  7. ^ Cite error: The named reference philae-jgu was invoked but never defined (see the help page).
  8. ^ "Alpha Proton X-ray Spectrometer (APXS) – Mission Name: Philae". NASA. 26 August 2014.
  9. ^ "Payloads for Chandrayaan-2 Mission Finalised". isro.gov.in. Indian Space Research Organisation. 30 August 2010. Archived from the original on 15 October 2012. Retrieved 7 August 2012.