Turbulence Heating ObserveR – satellite mission proposal

Abstract

The Universe is permeated by hot, turbulent, magnetized plasmas. Turbulent plasma is a major constituent of active galactic nuclei, supernova remnants, the intergalactic and interstellar medium, the solar corona, the solar wind and the Earth’s magnetosphere, just to mention a few examples. Energy dissipation of turbulent fluctuations plays a key role in plasma heating and energization, yet we still do not understand the underlying physical mechanisms involved. THOR is a mission designed to answer the questions of how turbulent plasma is heated and particles accelerated, how the dissipated energy is partitioned and how dissipation operates in different regimes of turbulence. THOR is a single-spacecraft mission with an orbit tuned to maximize data return from regions in near-Earth space – magnetosheath, shock, foreshock and pristine solar wind – featuring different kinds of turbulence. Here we summarize the THOR proposal submitted on 15 January 2015 to the ‘Call for a Medium-size mission opportunity in ESAs Science Programme for a launch in 2025 (M4)’. THOR has been selected by European Space Agency (ESA) for the study phase.

Intermittent turbulence in the heliosheath and the magnetosheath plasmas based on Voyager and THEMIS data

“…On the other hand, the level of intermittency for the outgoing fluctuations (z + ) seems to be approximately similar to that for the ingoing fluctuations (z − ). In view of the space investigation in the near future, including the THOR mission (e.g., Vaivads et al, 2016), we expect that the difference in characteristic behavior of these fluctuations in various regions of the magnetosheath will be able to help in identifying some new complex structures in space plasmas.…”

Review article: Wave analysis methods for space plasma experiment

“…While many of the current spacecraft missions perform multi-point measurements -four-point tetrahedral formation flights on scales of 10 000 down to 100 km by the Cluster mission (Escoubet et al, 2001) and on a 10 km scale by the MMS mission (Burch et al, 2016), 1-D fivepoint measurements by the THEMIS mission (Angelopoulos, 2008), three-point measurements by the Swarm mission Olsen et al, 2013;Thebault et al, 2013), and two-point measurements by the Van Allen Probes (Mauk et al, 2013;Stratton et al, 2013) -the upcoming spacecraft missions are more specialized to unique observational approaches toward the understanding of turbulence processes (particularly in interplanetary space) at the cost of returning back to single spacecraft measurements. Examples are simultaneous remote sensing and in situ measurements by Solar Orbiter (Müller et al, 2013), the closest observations to the Sun by Solar Probe Plus (Fox et al, 2016), and highprecision sampling of particle velocity distribution functions, electric fields, and magnetic fields by THOR (Vaivads et al, 2016). Analysis of spatial structure or intermittency is not covered here, and will be presented in separate papers.…”

On the Importance of Spatial and Velocity Resolution in the Hybrid-Vlasov Modeling of Collisionless Shocks

“…It is equally crucial in the study of laboratory plasmas [e.g., 1], in the design of fusion devices [e.g., 2] and spacecraft [e.g., 3] or to provide context to and interpretations of observations in space, helio-and astrophysics [e.g., [4][5][6]. Simulation methods for plasma can be broadly classified according to the amount of physical detail they include [e.g.…”