The outer regions of the solar corona and the solar wind are sufficiently tenuous that the plasma is not efficiently equilibrated by particle collisions. In such cases, plasma waves can play a crucial, if not dominant role in the dynamical behavior. This can lead to phenomena associated with plasma and particle acceleration, manifested in the flow of the solar wind and the acceleration of particles at shock waves propagating within it.
We undertake a program combining in situ measurements of element abundances and charge states (e.g., with the Advanced Composition Explorer) and remotely sensed imaging and spectroscopy (e.g., with Hinode/Extreme Ultraviolet Spectrograph or various instruments on the SDO and SOHO spacecraft). The aims are to understand the origins and source regions of the solar wind and to understand the conditions necessary for the development of solar energetic particle (SEP) events, with a view to an eventual forecasting capability. The Ultraviolet Spectro-Coronagraph Pathfinder (UVSC-Pathfinder) is an experiment under development for the Department of Defense Space Test Program, designed to search for suprathermal ions in the solar corona, thought to be a necessary pre-condition for a shock wave driven by a coronal mass ejection (CME) to produce an SEP event.
Moses JD, Ko YK, Laming JM, Provornikova EA, Strachan L, Tun Beltran ST: “Ultraviolet and Extreme Ultraviolet Spectroscopy of the Solar Corona at the Naval Research Laboratory”. Applied Optics 54: F222, 2015
Laming JM: “The FIP and Inverse FIP Effects in Solar and Stellar Coronae”. Living Reviews in Solar Physics 12: 2, 2015
Laming JM, Moses JD, Ko YK, Ng CK, Rakowski CE, Tylka AJ: ”On the Remote Detection of Suprathermal Ions in the Solar Corona and their Role as Seeds for Solar Energetic Particle Production”. Astrophysical Journal 770: 73, 2013
Atomic physics; Plasma physics; Shock waves; Solar physics; Solar wind; Spectroscopy;