World’s Smallest Ion Thruster
Transcription
World’s Smallest Ion Thruster
World’s Smallest Ion Thruster Busek’s BIT-1 RF ion thruster is an ultra-compact, high-performance ion propulsion device designed with nano-satellite users in mind. Weighing just 53 grams and having a size close to a U.S. quarter, the BIT-1 thruster can produce 105 µN thrust and 2250 second Isp with just 10W of power. When higher power is available, the thruster’s performance can easily exceed 200 µN thrust and 3500 second Isp. As with other Busek RF ion thrusters, BIT-1 employs inductively-coupled plasma (ICP) discharge to generate its ion source. The utilization of RF discharge eliminates the need for internal hot cathode and thus increases overall lifetime while enabling extreme miniaturization. Thruster life is dominated by grid erosion, which by simulation exceeds 20,000 hours. BIT-1 by default is paired with Busek’s subminiature hollow cathode BHC-50E for ion beam neutralization. In addition to its small size and low power, BIT-1 is designed to be compatible with the solid-storable propellant iodine. Such unique properties make the BIT-1 system extremely favorable for nano-satellites such as CubeSats, where volume and mass are highly constrained. Miniaturized, microcontrollerbased Power Processing Unit (PPU) for BIT-1 also exists in the CubeSat form factor. The PPU contains an innovative RF generator/amplifier board with integrated load power sensor and automatic frequency matching. Based on a modified Class E RF amplifier topology, the RF board has a proven 80% DC-to-RF power conversion efficiency for BIT-1 operation. Very precise thrust output is possible with this technology, as well as multiple modes of operation, ranging from higher to lower specific impulse. BIT-1 RF Ion Thruster BIT-1 Operating with Xenon at 14W High-Efficiency RF Generator/Amplifier Board in the CubeSat Form Factor w w w . b u s e k . c o m Est. Thurst from Beam Current, µN Envelope Drawing 240 220 200 180 160 140 120 100 80 60 40 20 0.06sccm 0.05sccm 0.04sccm 6 7 8 9 10 11 12 13 14 15 16 Total Thruster Power* Ion Beam Current Propellant Mass Flow Thrust Specific Impulse Propellant Utilization Energy Efficiency** Grid Input Voltage Thruster Mass*** 10 W 1.5 mA 4.9 µg/sec Xe 105 µN 2250 sec 43% 28% 2 kV 53 g 5000 4500 4000 3500 3000 0.05sccm 2000 0.04sccm 1500 1000 500 0 7 8 9 10 11 12 13 14 15 16 Total Thruster Power (RF + DC), W 42% 38% * Does not include PPU efficiency or neutralizer consumption ** Defined as Pgrids/(Pgrids + PRF) *** A complete BIT-1 propulsion system will need to include neutralizer, PPU, feedsystem, and propellant tank 34% 30% 0.06sccm 26% 0.05sccm 22% 0.04sccm 18% 14% 10% 6 Performance Characteristics (Xe) 7 8 9 10 11 12 13 14 15 16 Total Thruster Power (RF + DC), W 16 100% 15 90% 14 80% 13 12 0.06sccm 11 0.05sccm 10 0.04sccm 9 8 Propellant Utilization Total Thruster Power (RF + DC), W 0.06sccm 2500 6 Energy Efficiency Nominal Specification Est. Isp from Beam Current, sec Total Thruster Power (RF + DC), W 70% 60% 0.06sccm 50% 0.05sccm 40% 0.04sccm 30% 20% 10% 7 0% 6 5 6 7 8 9 10 6 RF Load Power (Discharge Power), W 7 8 9 10 11 12 13 14 15 16 Total Thruster Power (RF + DC), W Busek Co. Inc. 11 Tech Circle, Natick, MA 01760 | 508.655.5565 | [email protected] Copyright 2014, Busek Co. Inc. All Rights Reserved. 70011950 Rev-