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Mossbauer Spectrometer (MB)

NSSDCA ID: 2003-032A-04

Mission Name: Opportunity
Principal Investigators:Dr. Steven W. Squyres
Principal Investigators:Dr. Goestar Klingelhoefer

Description

The Mossbauer Spectrometer (MB) is designed specifically to study iron-bearing minerals. The sensor head for the MB is mounted on the end of the rover arm, or instrument deployment device. The arm can place the sensor head directly on a sample to be studied. A single measurement takes about 12 hours. The electronics board for the MB, with a mass of about 0.14 kg and a volume of 16 x 10 x 2.5 cm is contained in the warm electronics box in the body of the rover. The MB was built by the Mossbauer Group at Johannes Gutenberg University.

The sensor head has a mass of about 0.41 kg and a volume of about 9.0 cm x 5.0 cm x 4.0 cm and contains a 57Co/Rh source to illuminate the target. The source is moved at a known velocity by a Mossbauer drive and backscattered radiation is measured by gamma- and x-ray detectors in the sensor head. The gamma signals are binned by source velocity. The mineralogical information on the target is given by hyperfine splitting of 57Fe nuclear levels. There are five analog detector channels which are analyzed by discriminators for 14.41 keV and 6.4 keV peaks. Mossbauer spectra for the two energies are sampled separately, each consisting of 512 x 3-byte integers. Calibration spectra will be taken during sampling using a reference channel in the instrument. A magnetite-rich calibration target will also be mounted on the rover where it can be directly viewed by the MB. The 12-hour measurement run will be timed to include daytime maxima and nighttime minima temperatures to use the temperature dependent behavior of the Mossbauer parameters to help determine the nature of the iron-bearing phases.

During cruise phase tests it was discovered that the internal calibration channel on the MB was not functioning properly. This is not a critical problem as the external calibration target can be used.

Alternate Names

  • MB
  • Moessbauer Spectrometer
  • Opportunity/MB

Facts in Brief

Mass: 0.55 kg
Power (avg): 2 W

Funding Agency

  • NASA-Office of Space Science Applications (United States)

Discipline

  • Planetary Science: Geology and Geophysics

Additional Information

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

 

Personnel

NameRoleOriginal AffiliationE-mail
Prof. Raymond E. ArvidsonDeputy Principal InvestigatorWashington Universityarvidson@wunder.wustl.edu
Dr. Goestar KlingelhoeferLead InvestigatorJohannes Gutenberg Universitatklingel@mail.uni-mainz.de
Dr. Steven W. SquyresPrincipal InvestigatorCornell Universitysws6@cornell.edu

Selected References

  • Klingelhoefer, G., et al., Athena MIMOS II Moessbauer spectrometer investigation, J. Geophys. Res., 108, No. E12, 8067, doi:10.1029/2003JE002138, 2003.
  • Klingelhoefer, G., et al., Jarosite and hematite at Meridiani Planum from Opportunity's Mossbauer spectrometer, Science, 306, No. 5702, 1740-1745, Dec. 2004.
  • Morris, R. V., et al., Moessbauer mineralogy of rock, soil, and dust at Meridiani Planum, Mars: Opportunity's journey across sulfate-rich outcrop, basaltic sand and dust, and hematite lag deposits, J. Geophys. Res., 111, E12S15, doi:10.1029/2006JE002791, 2006.
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