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Particle Impact Analyser (PIA)

NSSDCA ID: 1985-056A-04

Mission Name: Giotto
Principal Investigator:Dr. Jochen Kissel


The objective of this investigation is to determine the chemical and physical properties of the dust particles released by Comet Halley. The instrument is a redesign of the one flown on Helios-A and -B by Fechtig and colleagues. The chemical composition and the mass of individual particles are measured. The impact count as a function of the position relative to the comet's nucleus provides the mass distribution and the rate of production of dust. The measurements should provide (1) the elemental abundance of individual particles, (2) compositional distribution around the comet, and (3) determination of specific isotopic ratios, such as 6Li/7Li, 10B/11B, or 12C/13C. The instrument consists of (1) an adjustable entrance port, (2) a target of atomic mass >105, (3) a set of acceleration grids, (4) a two-section time-of-flight drift tube, (5) an ion reflector chamber, and an electron multiplier tube. The particles are measured by the charge of the impact plasma, the impact light flash, and mass dispersion through the time-of-flight tube. Calibration with a ground-based dust accelerator is imperative to the interpretation of the data. The instrument handles an impact rate up to 100/s, which is controlled by the variable entrance port (1 - 500 sq mm) under microprocessor control and covers the particle mass range from 3.E-16 to 5.E-10 g. The mass resolution M/delta M is 200 at 100 u and the dynamic range that can be handled in one mass spectrum is 1.E3. Additional detail for this instrument can be found in "The Particulate Impact Analyzer, an Instrument to Analyze Small Particles Released by Halley's Comet" by J. Kissel, ESA SP-169, June 1981.

Alternate Names

  • Giotto/PIA
  • PIA
  • urn:esa:psa:context:instrument:gio.pia

Facts in Brief

Mass: 9.89 kg
Power (avg): 9.1 W
Bit rate (avg): 2.891 kbps


  • Planetary Science: Small Bodies

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. Hugo FechtigCo-InvestigatorMax-Planck-Institut fur Kernphysik
Dr. Herbert A. ZookCo-InvestigatorNASA Johnson Space Center
Prof. Heinrich J. VolkCo-InvestigatorMax-Planck-Institut fur
Dr. Eberhard GruenCo-InvestigatorMax-Planck-Institut fur
Dr. Benton C. ClarkCo-InvestigatorMartin-Marietta
Dr. J. A. M. McDonnellCo-InvestigatorUniversity of Kent,
Dr. Greogor E. MorfillCo-InvestigatorMax-Planck-Institut fur Physik und
Dr. Juergen H. RaheCo-InvestigatorBamberg Observatory
Dr. Gerhard H. SchwehmCo-InvestigatorRuhr-Universitat Bochum
Dr. Eduard B. IgenbergsCo-InvestigatorTechnische Universitat
Dr. Zdenek SekaninaCo-InvestigatorNASA Jet Propulsion
Dr. Franz R. KruegerCo-InvestigatorMax-Planck-Institut fur Kernphysik
Dr. N. G. UtterbackCo-InvestigatorNASA Jet Propulsion Laboratory
Mr. K. KornungCo-InvestigatorUniversity at Munich-Neubiberg
Dr. E. K. JessbergerCo-InvestigatorMax-Planck-Institut fur Kernphysik
Dr. Jochen KisselGeneral ContactMax-Planck-Institut fur Kernphysik
Dr. Jochen KisselPrincipal InvestigatorMax-Planck-Institut fur Kernphysik

Selected References

  • Lawler, M. E., et al., Iron, magnesium, and silicon in dust from comet Halley, Icarus, 80, No. 2, 225-242, doi:10.1016/0019-1035(89)90135-8, Aug. 1989.
  • Kissel, J., The Giotto particulate impact analyser, in The Giotto Mission--Its Scientific Investigations, ESA SP-1077, edited by R. Reinhard and B. Battrick, pp. 67-83, Mar. 1986.
  • Kissel, J., et al., Composition of comet Halley dust particles from Giotto observations, Nature, 321, No. 6067, 336-337, doi:10.1038/321336a0, May 1986.
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