New Multidirectional Electron Detector to Advance Aurora Studies

New Multidirectional Electron Detector to Advance Aurora Studies
by Clarence Oxford
Los Angeles CA (SPX) Apr 10, 2024

The enigmatic aurora borealis, known for its visual spectacle, is propelled by energetic electrons whose complex dynamics are not yet fully comprehended. Current tools used to study these electrons are limited by their capability to sample multiple energies swiftly. To address this, NASA has developed a new tool that drastically improves the frequency and detail of measurements by a significant margin, thus unlocking new insights into the aurora's intricate physics.

Traditionally, electron analysis in aurora studies has depended on electrostatic deflection methods, effective for capturing data at a second to sub-second resolution but inadequate for millisecond fluctuations. This method has been instrumental in gathering the vast majority of in-situ electron data within the aurora across numerous space missions.

The rapid spatial and temporal shifts in aurora, evident from ground-based optical observations, are beyond the reach of conventional electron detectors. In response, the team at NASA's Goddard Space Flight Center developed the Acute Precipitating Electron Spectrometer (APES), capable of capturing electron precipitation at a rate of one millisecond. APES utilizes a robust magnetic field to segregate electrons of varying energies into different zones of the detector, allowing simultaneous spectrum analysis.

While APES effectively measures electrons falling toward the Earth, it's constrained to single-direction observations. To expand the capabilities, the Goddard team devised APES-360, an advancement that maintains the core principles of APES but introduces a 360-degree viewing angle via a new multi-directional design covering 16 sectors. This design was challenged by the need to integrate a larger number of anodes and complex circuitry within a confined space.

Currently, the APES-360 prototype is under construction and will undergo testing and calibration at Goddard. It's scheduled for a trial on a sounding rocket during an active aurora phase in winter 2025, which will provide crucial data to verify its functionality and guide further enhancements.

Additionally, the design of APES-360 is compatible with CubeSat dimensions, making it suitable for future small satellite missions aimed at aurora research, with potential applications in larger orbital projects as well.