The PIT Mark VI Pulsed Inductive Thruster

TLDR

The pulsed inductive thruster (PIT) is an electrodeless, magnetic rocket engine capable of operating with any gaseous propellant. The MkV PIT operates by injecting a gas puff against a flat spiral coil, ionizing it with a fast‑rising current pulse from a capacitor bank, and ejecting the plasma; the 1‑m design achieves low engine mass at low power and can deliver over 1 MW, with performance data reported for ammonia and hydrazine. Single‑shot tests on an impulse balance show that the PIT achieves over 50 % efficiency from 4000 to >8000 s Isp at 32 kV, with a 20 kW design yielding a specific mass comparable to ion engines for 10 000‑hour operation and a 100 000‑hour design one‑third that of ion engines; higher coil voltages could extend the Isp range further.

Abstract

The pulsed inductive thruster (PIT) is an electrodeless, magnetic rocket engine that can operate with any gaseous propellant. A puff of gas injected against the face of a flat (spiral) coil is ionized and ejected by the magnetic field of a fast-rising current pulse from a capacitor bank discharge. Single shot operation on an impulse balance has provided efficiency and I(sub sp) data that characterize operation at any power level (pulse rate). The 1-m diameter MkV thruster concept offers low estimated engine mass at low powers, together with power capability up to more than 1 MW for the 1-m diameter design. A 20 kW design estimate indicates specific mass comparable to Ion Engine specific mass for 10,000 hour operation, while a 100,000 hour design would have a specific mass 1/3 that of the Ion Engine. Performance data are reported for ammonia and hydrazine. With ammonia, at 32 KV coil voltage, efficiency is a little more than 50 percent from 4000 to more than 8000 seconds I(sub sp). Comparison with data at 24 and 28 kV indicates that a wider I(sub sp) range could be achieved at higher coil voltages, if required for deep space missions.