Turning Instrument Background Into Science Data for Structural Features of Radiation Belts

Area of Science:

• Space Physics
• Plasma Physics
• Geophysics

Background:

• Energetic particle radiation belts pose challenges for space instrument data analysis.
• Background counts in instruments like Cluster CIS HIA and Double Star HIA are primarily caused by penetrating energetic particles.

Purpose of the Study:

• To develop and present methods for converting instrument background counts into scientifically valuable data.
• To determine the boundaries of the Earth's inner and outer radiation belts.
• To investigate the presence of a third radiation belt or storage ring.

Main Methods:

• Utilizing background counts from Cluster CIS HIA and Double Star HIA instruments.
• Analyzing simultaneous increases in all energy channels in HIA spectrograms to identify radiation belt entries and exits.
• Exploiting supplementary data streams within CODIF telemetry, including "start," "stop," and "non-valid" signals, when HIA data is unavailable.
• Defining radiation belt boundaries by analyzing changes in count gradients over time and visual inspection of measurements.

Main Results:

• Demonstrated methods for using background counts to determine radiation belt boundaries.
• Successfully identified radiation belt boundary locations using both HIA and CODIF data.
• Analyzed data from July-August 2007 and September-October 2012 to demonstrate the methods' effectiveness.

Conclusions:

• Instrument background counts can be transformed into scientifically valuable data for space physics research.
• The proposed methods provide reliable ways to determine radiation belt boundaries, even with limited HIA data.
• The analysis of specific time periods provides insights into the structure of the radiation belts.