Heliophysics Science Division
Sciences and Exploration Directorate - NASA's Goddard Space Flight Center

October 29, 2010, 12:00 pm - 1:00 pm

October 29, 2010, 12:00 pm - 1:00 pm

Benefits of Large Geometric Factor, High Energy-Resolution, Low-Energy Charged Particle Analyzers for Heliophysics Research



Luke Goembel (Goembel Instruments)

High energy-resolution charged particle spectrometers, often used in laboratory-based space physics research, have rarely been used in space. Previously, to keep instruments smaller in size, energy-resolution has been sacrificed in order to collect data rapidly in the low charged-particle fluxes typically encountered in space. Technology is now available that makes it possible to have both high energy-resolution and a large geometric factor even at energies as low as 1 eV. Instruments using this technology can be built with an order-of-magnitude higher energy resolution and/or an order-of-magnitude larger geometric factor with no corresponding increase in mass. Such technology has compelling applications in heliophysics research. The rapid collection of high energy-resolution heliospheric ion and electron spectra may reveal features that give insight into the Sun-Earth connection, space weather, and heliospheric physics in general. An immediate application of the technology is a low mass, easily deployed, accurate spacecraft charge monitor that can be used to correct spacecraft charge-induced biases to space plasma analyzers, thereby eliminating one of the great uncertainties in low energy space plasma analysis - the uncertainty of the spacecraft floating potential. Compact, high geometric factor, high energy-resolution solar wind speed, direction, density and temperature monitors based on the technology could also be deployed that would collect data with 0.1-second time resolution rather than the 60-second time resolution typical for similar data from ACE and WIND. Such high frequency data collection would enable the study of solar wind plasma fine structure and give insight into transient phenomena such as heliospheric magnetic holes, shock waves, and discontinuities.