| 词条 | Dual-Stage 4-Grid |
| 释义 |
The Dual-Stage 4-Grid (DS4G) is an electrostatic ion thruster design developed by the European Space Agency,[1] in collaboration with the Australian National University.[2] The design was derived by D. Fern from Controlled Thermonuclear Reactor experiments that use a 4-grid mechanism to accelerate ion beams. A 4-grid ion thruster with only 0.2 m diameter is projected to absorb 250 kW power. With that energy input rate, the thruster could produce a thrust of 2.5 N. The specific impulse (a measure of fuel efficiency), could reach 19,300 s at an exhaust velocity of 210 km/s if xenon propellant were used.[3] The potentially attainable power and thrust densities would substantially extend the power absorption of current ion thrusters to far more than 100 kW. These characteristics facilitate the development of ion thrusters that can result in extraordinary high-end velocities.[3] Like with thruster concepts such as VASIMR, the dual-stage-4-grid ion thrusters are mainly limited by the necessary power supply for their operation. For example, if solar panels were to supply more than 250 kW, the size of the solar array would surpass the size of the solar panels of the International Space Station. To provide 250 kW with Stirling radioisotope generators would require roughly 1 tonne of plutonium-238 (for which the US stockpile as of 2013 was no more than 20 kg[4]), and so a nuclear thermal reactor would be needed. Comparison{{main list|Spacecraft propulsion#Table of methods}}{{Specific impulse examples}}See also
References1. ^{{cite web|title=Dual-Stage Gridded Ion Thruster (DS4G) | publisher = ESA Advanced Concepts Team — Advanced Propulstion | url = http://www.esa.int/gsp/ACT/projects/ds4g_overview.html}} {{reflist|group=lower-alpha}}{{Space-stub}}2. ^{{cite web | title=Dual stage 4 grid thruster | publisher = ANU Centre for Plasmas & Fluids | url = https://physics.anu.edu.au/cpf/sp3/ds4g/}} 3. ^1 THE INNOVATIVE DUAL-STAGE 4-GRID ION THRUSTER CONCEPT – THEORY AND EXPERIMENTAL RESULTS 4. ^{{cite web|last=Mosher|first=Dave|title=NASA’s Plutonium Problem Could End Deep-Space Exploration|url=https://www.wired.com/wiredscience/2013/09/plutonium-238-problem/|publisher=Wired|accessdate=20 September 2013}} 1 : Ion engines |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。