Payload (II)

Instrument Descriptions

The SMART payload comprises three instrument groups: Hot Plasma, Energetic Particles, and Fields. In addition, the payload includes two Active Spacecraft Potential Control Devices (ASPOC) and a Central Instrument Data Processor (CIDP). The ASPOCs neutralize the electrical potential of the spacecraft, allowing measurement of low-energy ions and electrons by the plasma instruments and eliminating spurious electric fields that can contaminate double-probe measurements. The CIDP provides the interface between the instruments and the spacecraft C&DH subsystem. The ASPOCs are being developed at the Institut fuer Weltraumforschung of the Austrian Academy of Sciences; the CIDP is being developed at Southwest Research Institute.

I. Hot Plasma

• Fast Plasma Instrument (FPI): The FPI consists of Dual Ion Sensors and Dual Electron Sensors and measures 3D ion and electron flux distributions over the energy range ~10 eV to 30 keVwith an energy resolution of 20%. Electrons will be measured with a time resolution of 30 ms, ions with a time resolution 150 ms. The FPI investigation is led by Co-I C. Pollock (GSFC).
• Hot Plasma Composition Analyzer (HPCA): The HPCA employs a novel RF technique to measure minor ions such as oxygen and helium in regions of high flux. Energy range = ~10 eV to 30 keV; energy resolution = 20%; time resoluton = 15 s. The HPCA investigation is led by Co-I S. A. Fuselier (SwRI).

Energetic Particles