BackForwardInstrument:  SWIMS 

Instrument details
Acronym SWIMS
Full name Solar Wind Ion Mass Spectrometer
Purpose To measure solar wind composition data over a wide range of solar wind bulk speeds and for all solar wind conditions; and abundances of most of the elements and several isotopes
Short description Uses a time-of-flight (TOF) measurement technique to determine the mass of a solar wind ion with high accuracy in the range 4-60 amu (atomic mass unit), i.e. He to Ni, every few minutes. Energy range approximately 0.5-20 keV/n
Background Part of a package of instruments for solar observation
Scanning Technique Interplanetary observation from the L1 Lagrange libration point
Resolution N/A
Coverage / Cycle Large fraction of the interplanerary space, nearly continuous
Mass 8.3 kg Power 19.4 W Data Rate 505 bps


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1998 to ≥2026
Last update: 2021-11-10
Detailed characteristics
Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Solar and space environment monitors
  • Energetic particle spectrometer
WIGOS Subcomponents
  • Subcomponent 1
  • Solar wind at L1 - Alpha-particle sensor
  • Solar wind at L1 - Heavy ion sensor
Mission objectives
Primary mission objectives
  • Alpha particles differential directional flux
  • Heavy ion flux energy and mass spectrum
Show allShow fewer
Tentative Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
VariableRelevance for measuring this variableOperational limitationsExplanation
Alpha particles differential directional flux2 - very highNo specific limitation.Interplanetary space. Low-medium energy range (<10 up to 100 MeV/n)
Heavy ion flux energy and mass spectrum4 - fairNo specific limitation.Interplanetary space. Low-medium energy range (<10 up to 100 MeV/n)