Hall Effect Thruster
A electric space propulsion plasma engine that accelerates ions across an electrostatic potential drop using trapped electrons in an annular magnetic field.
Governing formula
F_thrust = ṁ v_exhaust, v_ex = √(2 e V_acc / m_ion)
SI unit
N or mN (Thrust) & s (Specific Impulse ~1500–3000 s)
In depth
Radial magnetic fields trap electrons in a circular E × B drift motion. Trapped electrons ionize propellant gas (xenon or krypton) and establish an axial electric field that accelerates ions outward to high exhaust speeds (~30 km/s).
Examples in the real world
Hall thrusters providing station-keeping and orbit insertion for Starlink communications satellites.