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Ion Composition Analyser (ICA)

NSSDCA ID: 2004-006A-15

Mission Name: Rosetta
Principal Investigator:Dr. Hans Nilsson


The Ion Composition Analyser (ICA) is designed to determine the energy and direction of solar wind and cometary ions, and separate ion species by measuring the charge to mass ratio. The ICA is part of the Rosetta Plasma Consortium (RPC) which consists of four additional instruments: the Langmuir Probe Instrument (LAP), the Ion and Electron Sensor (IES), the Fluxgate Magnetometer (MAG), and the Mutual Impedance Probe (MIP). The scientific objectives of the RPC instruments are to study inner coma structure, dynamics, and aeronomy, characterize the development of cometary activity and the formation and evolution of plasma tail, and investigate solar-wind and asteroid interaction.

The ICA is mounted on the top (comet-facing) side of the orbiter. It consists of an electrostatic entrance angle system, an electrostatic tophat analyzer, and a cylindrical momentum analyzer. The tophat uses the toroidal analyzer approach and has a 360 degree field of view. The momentum analyzer is a mass/charge time-of-flight velocity analyzer based on permanent magnets. The ICA provides the azimuth angle and mass per charge of incident ions in a 16 (angle) vs 32 (mass) array. The mass range is 1 to approximately 10^12 amu, which includes submicron sized dusty plasma particles. Energy/charge is measured at 7% resolution from 1 eV/q to 40 eV/q. A 2D distribution is obtained in 4 s and a 3D distribution in 64 s. Onboard control is provided by the Plasma Interface Unit (PIU), a common interface to the spacecraft for the RPC experiments.

Alternate Names

  • ICA
  • Rosetta/ICA
  • urn:esa:psa:context:instrument:ro.rpcica

Facts in Brief

Mass: 2.02 kg
Power (avg): 4.2 W


  • Planetary Science: Small Bodies
  • Planetary Science: Fields and Particles

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. Hans NilssonPrincipal InvestigatorSwedish Institute for Space

Selected References

  • Trotignon, J. G., et al., The Rosetta Plasma Consortium: Technical realization and scientific aims, Adv. Space Res., 24, No. 9, 1149-1158, June 1999.
  • Carr, C., et al., RPC: The Rosetta Plasma Consortium, Space Sci. Rev., 128, 629-647, doi:10.1007/s11214-006-9136-4, 2007.
  • Nilsson, H., et al., RPC-ICA: The Ion Composition Analyzer of the Rosetta Plasma Consortium, Space Sci. Rev., 128, 671-695, doi:10.1007/s11214-006-9031-z, 2007.

Other Related Data/Information

Image of EASEP

Rosetta RPC

RPC Home Page (Rosetta Plasma Consortium)

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