EMFISIS on RBSP

Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS)

The RBSP-EMFISIS investigation will focus on the important role played by magnetic fields and plasma waves in the processes of radiation belt particle acceleration and loss. EMFISIS offers the opportunity to understand the origin of important magnetospheric plasma waves as well as the evolution of the magnetic field that defines the basic coordinate system controlling the structure of the radiation belts and the storm-time ring current.

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The physics of the creation and loss of radiation belt particles is intimately connected to the electric and magnetic fields which mediate these processes. A large range of field dynamics and time scales are involved in this physics from ring current magnetic fields to microscopic kinetic interactions such as whistler-mode chorus waves with energetic electrons. To measure these key field interactions, NASA has selected the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) on the Radiation Belt Storm Probes (RBSP). EMFISIS is an integrated set of instruments consisting of a tri-axial fluxgate magnetometer (MAG) and a Waves instrument which includes a tri-axial search coil magnetometer and measures AC electric and magnetic fields from 10 Hz to MHz frequencies. The broad frequency range of the Waves instrument enables the identification of resonances and cutoffs from Waves to achieve high cadence, accurate plasma density measurements that are essential to RBSP theory and modeling efforts. The instruments are integrated through a Central Data Processor Unit (CDPU) which provides for flexible instrument operations in both burst and survey telemetry modes that can be optimized to address the specific physics of the many radiation belt processes. The EMFISIS multi-institution team comprises a group of knowledgeable space physics investigators, both experimental and theoretical, with the requisite capability, desire, and experience to accomplish the goals of the RBSP mission to further our nation's space weather capability. In combination with the selected double probe electric field and particle investigations on RBSP, EMFISIS will provide the essential measurements necessary to open the frontier of predictive capability for the Earth's highly variable radiation belts.

RBSP-EMFISIS Science Investigation Objectives =

• Differentiate among competing processes affecting the acceleration and transport of radiation particles
• Differentiate among competing processes affecting the precipitation and loss of radiation belt particles
• Quantify the relative contribution of adiabatic and non-adiabatic processes on energetic particles
• Understand the effects of the ring current and other storm phenomena on radiation electrons and ions
• Understand how and why the ring current and associated phenomena vary during storms

RBSP-EMFISIS Instrument Suite

Central Data Processing Unit (CDPU): Instrument control, spacecraft interface, on-board analysis, 50 Mbyte mass memory.

Tri-axial Magnetometer (MAG) MAG is a tri-axial fluxgate magnetometer: Vector B, DC-15 Hz, 0.1 nT accuracy, three sensors on rigid boom.

WAVES, a tri-axial search coil magnetometer and sweep frequency receiver.

Waves Components:

• Magnetic field - vector B

10 Hz - 12 kHz sensitivity: 3x10-11 nT2Hz-1 @ 1 kHz 3 sensors on rigid boom

• Electric field - spin-plane E

10 Hz- 12 kHz (vector) 10 kHz-400 kHz (single channel) sensitivity: 3x10-17 V2m-2Hz-1 @ 1 kHz shares booms with Electric Fields and Waves (EFW) Instrument

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Instruments Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS)

The RBSP-EMFISIS investigation will focus on the important role played by magnetic fields and plasma waves in the processes of radiation belt particle acceleration and loss. EMFISIS offers the opportunity to understand the origin of important magnetospheric plasma waves as well as the evolution of the magnetic field that defines the basic coordinate system controlling the structure of the radiation belts and the storm-time ring current.

RBSP-EMFISIS Science Investigation Objectives:

• Differentiate among competing processes affecting the acceleration and transport of radiation particles
• Differentiate among competing processes affecting the precipitation and loss of radiation belt particles
• Quantify the relative contribution of adiabatic and non-adiabatic processes on energetic particles
• Understand the effects of the ring current and other storm phenomena on radiation electrons and ions
• Understand how and why the ring current and associated phenomena vary during storms

RBSP-EMFISIS Instrument Suite:

Central Data Processing Unit (CDPU): Instrument control, spacecraft interface, on-board analysis, 50 Mbyte mass memory.

Tri-axial Magnetometer (MAG) MAG is a tri-axial fluxgate magnetometer: Vector B, DC-15 Hz, 0.1 nT accuracy, three sensors on rigid boom.

WAVES, a tri-axial search coil magnetometer and sweep frequency receiver.

Waves Components:

• Magnetic field - vector B

10 Hz - 12 kHz sensitivity: 3x10-11 nT2Hz-1 @ 1 kHz 3 sensors on rigid boom

• Electric field - spin-plane E

10 Hz- 12 kHz (vector) 10 kHz-400 kHz (single channel) sensitivity: 3x10-17 V2m-2Hz-1 @ 1 kHz shares booms with Electric Fields and Waves (EFW) Instrument

EMFISIS accommodation diagram

RBSP-EMFISIS Data Products

MAG

• Rapid delivery of four vectors/second in a variety of coordinate systems (GSE, GSM, S/C, etc.)
• Later delivery of 20 vectors/second (32 vectors/second burst) at full Level 1 quality

WAVES

• Spectral matrices for 10 Hz –12 kHz with a 6-second cadence (more often is desired and necessary for some objectives)
• Spectrum, wave normal, and polarization summaries, based on both on-board and ground processing at 6-second cadence (or more often)
• Electric field spectrum to 7 MHz with 6-second cadence; electron density from fUHR and continuum radiation cutoff
• Simultaneous 6-channel waveforms

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