3D Hybrid Simulation of Pure Magnetic Sail Including Ion-Neutral Collision Effect in Laboratory

Abstract

Magnetic Sail is a propellantless propulsion system proposed for an interplanetary space flight. The propulsive force is produced by the interaction between the magnetic field artificially generated by a hoop coil equipped with the magnetic sail and the solar wind. Three-dimensional hybrid particle-in-cell simulations are performed to reproduce the plasma flow structure around the magnetic sail and to measure the propulsive force of the magnetic sail with two different coil currents. We report the characteristics of the magnetosphere, such as the profile of the magnetic field and the predicted thrust values obtained by simulations, which agree well with laboratory experiments, when simulations are carried out by considering the ion-neutral collision effect. The hybrid particle-in-cell simulation carried out without considering the collisional effect gave a thrust value of 2.3 3.5 N, which can be applied to the thrust evaluation of the magnetic sail in a magnetosphere with size of 250 300 km in a collisionless interplanetary space.

3D Hybrid Simulation of Pure Magnetic Sail on Ion Inertial Scale in Laboratory

“…We investigated in that paper 12) the characteristics of the magnetosphere, such as the profile of the magnetic field, the thickness of the magnetopause current layer, and the predicted thrust value obtained by simulations on the MHD scale, which agreed well with laboratory experiment, when numerical simulations are carried out by considering the ion-neutral collision effect. In the present paper, in order to understand the characteristics of the plasma flow structure around the magnetosphere on the ion inertial scale, we compare the recent experimental results 13) with the numerical simulation results such as the profile of the density, magnetic field current density, and the obtained thrust value.…”

“…Their error bars represent the standard deviations, which are the root-mean-square (RMS) deviations from the mean. The black squares and gray triangles for r Li /L = 0.3 in the graph represent a scaled-down laboratory experiment in a space chamber 10) and the past numerical simulation results 12) obtained using the hybrid PIC code with the same parameters as the laboratory experiment, respectively. The black squares and gray triangles for r Li /L = 0.8 in the graph represent the present results of numerical simulation and experiment.…”

“…5a, 5b. The ratio of the width of this current layer to L is 10% wider than that in MHD scale 12) as the characteristics of the thickness of the current layer on ion inertial scale is explained in Fig. 2.…”

“…The degree of ionization α is defined as the ratio of the n sw to the density of ion and neutral gas (n sw + n n ). The degree of ionization α of 0.3 is used in the present simulation, which value is decided based on the past evaluation 12) . Most of the hydrogen molecules (H 2 ) dissociate into atoms (H) at a relatively high temperature of 1 eV.…”

“…To gain a better understanding of the plasma flow structure around a magnetosphere on the MHD scale, laboratory experiment using scale-down modeling [9][10][11] and numerical simulations 12) were performed for a 0.1-m-size magnetosphere which can produce a Newton-class thrust. We investigated in that paper 12) the characteristics of the magnetosphere, such as the profile of the magnetic field, the thickness of the magnetopause current layer, and the predicted thrust value obtained by simulations on the MHD scale, which agreed well with laboratory experiment, when numerical simulations are carried out by considering the ion-neutral collision effect.…”