Thermal Plasma Measurements with the Solar Probe Cup: An Estimate of Perihelion Data

Abstract:

Solar Probe Plus (SPP) will visit the Sub-Alfvénic corona for the first time, sampling the solar wind at proximities closer to the sun than ever before. The Solar Probe Cup (SPC) maintains an unobstructed view of the sun during perihelion, and measures thermal plasma properties including temperature, bulk velocity and density. We estimate the instrument's accuracy by modeling the entire SPC measurement and analysis chain. Using known, time varying plasma distributions as inputs, we produce a toy bulk plasma parameter data set including plasma temperature, bulk speed and density. By using the analytic Faraday Cup response functions in conjunction with laboratory performance from engineering model tests, we aim to produce a realistic preview of data expected from SPP’s first approach phase. Lastly, we estimate the likelihood SPC will measure distinguishing features of several prominent coronal heating mechanisms as a function of the SPC operational mode and cadence.