MMS HPCA: Magnetospheric Plasma Ion Composition at 0.625-Second Resolution

Five ion species—protons, alpha particles, helium ions, singly charged oxygen, and background counts—are measured across 63 energy levels every 0.625 seconds by NASA's MMS spacecraft. The Hot Plasma Composition Analyzer (HPCA) instruments capture data for 16 elevation anodes and 16 azimuths per half-spin period, covering an energy range from 1 eV to 40 keV. This Level 2 survey data is produced by the National Aeronautics and Space Administration and was last updated in March 2026.

Use Cases

• Modeling magnetospheric plasma dynamics based on multi-species ion measurements.
• Analyzing ion energy distribution across 63 discrete energy levels.
• Studying temporal plasma variations based on 0.625-second resolution data.
• Investigating ion composition ratios (H+, He++, He+, O+) in space environments.

Strengths

• Measures five distinct ion species (H+, He++, He+, O+, background) simultaneously.
• Provides high temporal resolution with data points every 0.625 seconds.
• Covers a broad energy spectrum from 1 eV to 40 keV across 63 energy steps.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data is provided in BIN format, which may require specialized tools for access and analysis.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Collected by the Hot Plasma Composition Analyzer (HPCA) instruments on the MMS spacecraft.

Time Range

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Freshness

Last updated 2026-03-13 06:01:40.538383; freshness should be verified.

Geography

Magnetospheric regions covered by the MMS spacecraft orbits.