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Instrument: TIMAS : Toroidal Imaging Mass-Angle Spectrograph |
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Associated Platforms POLAR Related Data Sets View all records related to this instrument Description The Toroidal Imaging Mass-Angle Spectrograph (TIMAS) instrument measures the full three-dimensional velocity distribution functions of all major magnetospheric ion species with one-half spin period time resolution. The TIMAS is a first order double focusing (angle and energy), imaging spectrograph that simultaneously measures all mass per charge components from 1 AMU/e to greater than 32 AMU/e over a nearly 360 degrees by 10 degree instantaneous field-of-view in 20 milliseconds. Mass per charge is dispersed radially on an anular microchannel plate detector and the azimuthal position on the detector is a map of the instantaneous 360 degrees field of view. With the rotation of the spacecraft, the TIMAS sweeps out a 4pi solid angle image in a half spin period. The energy per charge range from l5eV/e to 32 keV/e is covered in 28 non-contiguous steps spaced approximately logarithmically with adjacent steps separated by about 30%. In order to handle the large volume of data within the telemetry limitations the distributions are compressed to varying degrees in angle and energy, log-count compressed and then further compressed by a lossless technique. This data processing task is supported by two SA3300 microprocessors. The voltages (up to + 5 kV) for the tandem toroidal electrostatic analyzers are supplied from common high voltage supplies using optically controlled series-shunt regulators. For more information, see: http://lasp.colorado.edu/timas/TIMAS_description.html and http://pwg.gsfc.nasa.gov/polar/polar_inst.shtml Online Resources http://lasp.colorado.edu/timas/TIMAS_description.html Instrument Logistics Instrument Start Date: 1996-02-24 Instrument Owner: Lockheed Martin Missiles & Space Company Southwest Research Institute Mullard Space Science Laboratory, University College, UK University of Berne, Switzerland |
