Pulsed inductive thrusters (or PITs) are a form of ion thruster, used in spacecraft propulsion. A PIT uses perpendicular electric and magnetic fields to accelerate a propellant. A nozzle releases a puff of gas (usually ammonia or argon) which spreads across a flat induction coil of wire about 1 meter across. A bank of capacitors releases a pulse of electric current lasting 10 microseconds into the coil, generating a radial magnetic field. This induces a circular electrical field in the gas, ionizing it and causing the ions to revolve in the opposite direction as the original pulse of current. Because their motion is perpendicular to the magnetic field, the ions are accelerated out into space. Unlike an electrostatic ion thruster, PIT requires no electrodes (which are susceptible to erosion) and its power can be scaled up simply by increasing the number of pulses per second. A 1-megawatt system would pulse 200 times per second.
