RPW will make key measurements in support of the first three, out of four top-level scientific questions,
which drive Solar Orbiter overall science objectives:
- How and where do the solar wind plasma and magnetic field originate in the corona?
- How do solar transients drive heliospheric variability?
- How do solar eruptions produce energetic particle radiation that fills the heliosphere?
- How does the solar dynamo work and drive connections between the Sun and the heliosphere?
Here is the summary of the specific RPW Science Objectives:
- Solar and Interplanetary Radio Burst: - What is the role of shocks and flares in accelerating particles near the Sun? - How is the Sun connected magnetically to the interplanetary medium? - What are the sources and the global dynamics of eruptive events? - What is the role of ambient medium conditions on particle acceleration and propagation? - How do variations and structure in the solar wind affect low frequency radio wave propagation?
- Electron density and temperature measurements with the Quasi-Thermal Noise spectroscopy: - Precise measurement of both the electron density and temperature, with accuracies respectively of a few % and around 10 %, at perihelion. - Study the non-thermal character of the electron distributions at perihelion.
- Radio emission processes from electron beams: Langmuir waves and electromagnetic mode conversion: - Measurements for the first time in the Solar Wind of both the electric and magnetic field waveforms at high time resolution (up to 500 kSs). - Study of the mode conversion from Langmuir to electromagnetic waves. - Study of the energy balance between electron beams, Langmuir waves and e.m. radio waves at several radial distances
- Solar wind microphysics and turbulence: - Measure of the waves associated with the plasma instabilities that are generated by temperature anisotropies in the solar wind. - First DC/LF electric field measurements in the inner heliosphere and over a large radial distance in the solar.
- Shocks, Reconnection, Current Sheets, and Magnetic Holes: - Identification and study of the reconnection process in current sheets with thickness down to the ion scales and smaller. - Determination of the interplanetary shock structure down to the spatial and temporal scales comparable and smaller than the typical ion scales. - Determination of different particle energisation mechanisms within shocks and reconnection regions. - Distinguish different radio burst generation mechanisms. Interplanetary Dust - Determination, in combination with the EPD instrument, the spatial distribution, mass and dynamics of dust particles in the near-Sun heliosphere, in and out of the ecliptic.
To cover its specific Science Objectives, RPW will measure magnetic and electric fields at high time
resolution using a number of sensors, to determine the characteristics of electromagnetic and electrostatic
waves in the solar wind. More precisely, RPW will:
- Make the first-ever high accuracy, high-sensitivity and low noise measurements of electric fields at low frequencies (below ~1 kHz) in the inner Heliosphere.
- Measure the magnetic and electric fields of the solar wind turbulence with high sensitivity and dynamic range along the spacecraft trajectory.
- Store high-resolution data from scientifically interesting regions such as in-situ shock crossings, in-situ Type III events and others.
- Measure the satellite potential with high temporal resolution permitting to estimate the density fluctuations in the solar wind and allowing higher accuracy particle instrument measurements.
- Measure the quasi thermal noise and Langmuir waves around the local plasma frequency
- Measure for the first type the high frequency magnetic counterpart of Langmuir waves associated with in-situ Type III bursts
- Observe the solar and interplanetary radio burst
- Observe the radio counterpart of dust particle impacts
- Detect on-board in-situ shock crossings and store the corresponding data
- Detect on-board in-situ Type III events and store the corresponding data