UV Spectro-Coronagraphic Observations of Solar Energetic Particle Related Phenomena

Science Objectives:* Parameterize the coronal suprathermal seed population and

its role in the production of SEPs.

* Characterize the sources of SEPs and how they are accelerated to high energy.

* Provide a Space Environment predictive tool for the most geo-effective SEP events.

Associated RFAs:F2. Understand the plasma processes that accelerate and

transport particles.

H1. Understand the causes and subsequent evolution of solar activity that affects Earth’s space

J2. Develop the capability to predict the origin and onset of solar activity and disturbances associated with potentially hazardous space weather events.

Measurement Strategy:* Observe with externally occulted EUV/UV and WL

coronagraphs the spatial distribution of temperature, outflow velocity (via Doppler dimming) and Line-of-sight Doppler velocity, intensity, and density of multiple ions and electrons in the corona from 1.5 to 6 Solar radii.

* Provide high resolution EUV/UV spectral line profiles of ions with various charge to mass ratios including OVI, He II, H, and other species with bright resonance scattering simultaneously at multiple heights in the corona.

* Provide spectral profiles of the non-thermal distribution of OVI, He II, and H due to suprathermal particles.

Mission Implementation Description:*Atlas, 650 km Sun-synchronous (~98.6 degrees) orbit

*3-axis stabilized, Sun-pointing, Solar array powered

*EUV/UV imaging multi-slit spectro-coronagraph

*White light imaging coronagraph

*Payload mass: 250 Kg, Power: 150 W, Data Rate: 10 Mbps

Technology Development:* Mission can be accomplished with no new technology.

* Mission requires smaller pathfinder missions to identify key observables for measuring the suprathermal seed population distribution and the impact of the CME shock on the coronal material.

Multi-slit instantaneous

EUV/UV Spectra

1.8

2.0

2.4

2.7