The future of plasmaspheric extreme ultraviolet (EUV) imaging

This chapter considers the future of wide-field, plasmaspheric extreme ultraviolet (EUV) imaging, including reviews of previous work as well as some new material. We begin with a review of the technological and scientific progress made by the EUV imager that operated onboard the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft from 2000 to 2005. Analysis of the future of plasmaspheric EUV imaging is organized into three major topics. The first major topic is 30.4nm imaging of terrestrial He+ ions. We consider two improved 30.4nm camera designs, and their use to study important science topics such as fine-scale structure, erosion, and refilling. We analyze the benefits of three notional mission designs: continuous and/or stereo imaging from a high-inclination circular orbit, side-view imaging from geosynchronous orbit, and side-view imaging from the Moon. The second major topic is 83.4nm imaging of terrestrial O+ and O++ ions. We review the use of EUV imaging to provide much-needed system-level measurements of the dense oxygen torus—whose origin and global distribution remain unknown after decades of in situ observations. Simulated 83.4nm images demonstrate the scientific value of macroscale information about the oxygen torus. The third major topic is near-68 nm EUV imaging of the S++ ions in the Io plasma torus around the planet Jupiter. We review the Io torus's central role in driving convection in the Jovian magnetosphere, and the need for imaging to capture fundamental elements of this process. To achieve Io torus imaging we introduce a new EUV camera identical to IMAGE EUV except for a new multilayer mirror coating optimized for 68nm. We present simulated images to illustrate EUV imaging's enormous potential to explore, observe, and understand the Io plasma torus.