NASA Logo, National Aeronautics and Space Administration
NASA Space Science Data Coordinated Archive Header

X-Ray Detector

NSSDCA ID: 1966-017A-03

Mission Name: Cosmos 111


The X-Ray Detector Experiment was designed to use flourescent radiation from the lunar surface to constrain the composition of the regolith. The detectors were soft X-ray photon counters. Elements such as Mg, Al, Si, S, Ca, Ti, and Fe in the upper 1 mm of the lunar surface emit soft x-rays in the energy range 1-8 keV as a result of excitation by solar x-rays. Detection of these emissions gives an energy spectrum which allows an estimate of the quantities of these elements in the uppermost surface.

Alternate Names

  • Cosmos111/X-RayDetector

Funding Agency

  • Unknown (U.S.S.R)


  • Planetary Science: Geology and Geophysics

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. S. L. Mandel'shtamGeneral Contact
[] NASA Logo -