A new concept of ion thrusters, metal ion thrusters using magnetron electron-beam bombardment (MIT-MEB) is demonstrated. Ion thrusters provide thrusts via electrostatic fields to accelerate ions. They are widely used in spacecrafts due to the high exhaust speed. Although the thrust is very little, the final velocity of the spacecraft is much higher than using traditional rockets. For propellant, inert gases are used in conventional ion thrusters. Contrarily, a metal propellant is used in MIT-MEB. The metal propellant is solid-state, high density, easy to store, and cheap. The size of ion thrusters can be reduced dramatically. Therefore, they can be used in a small spacecraft for both attitude and orbit control, deep space exploration, and low earth orbit. The concept of electron-beam physical vapor deposition (EB-PVD) is used to generate metal ions. A metal target is bombarded and thus heated and evaporated. An electric potential accelerates thermal-emitted electrons, which ionize the metal vapor via electron-impacting ionization. The magnetic field of a permanent magnet is used to guide the accelerated electrons towards the center of the target. This increases the efficiency of the process. Particularly but not necessarily, zinc is used for propellant due to its higher vapor pressure compared with other metals at the same temperature. This means that a lower temperature is required for zinc to be vaporized. To demonstrate our concept, an ion thruster of 10.3 ± 0.7 μN with a power of 26.2 ± 0.7 W was constructed as a prototype. Its mass is less than 500 g, and its diameter is 50 mm. The accelerating electric potential is 1 kV. Although an optimized design was not developed yet, we demonstrated the feasibility of building metal ion thrusters for the first time. It is a new design space and unexplored method of using a metal propellant.

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使用磁控电子束轰击 (MIT-MEB) 的金属离子推进器

展示了离子推进器的新概念，即使用磁控电子束轰击 (MIT-MEB) 的金属离子推进器。离子推进器通过静电场提供推力以加速离子。由于排气速度高，它们被广泛用于航天器。虽然推力很小，但飞船的最终速度比使用传统火箭要高得多。对于推进剂，惰性气体用于传统的离子推进器。相反，MIT-MEB 使用金属推进剂。金属推进剂是固态的，密度高，易于储存，价格便宜。离子推进器的尺寸可以显着减小。因此，它们可用于小型航天器，用于姿态和轨道控制、深空探测和近地轨道。电子束物理气相沉积 (EB-PVD) 的概念用于生成金属离子。金属靶被轰击并因此被加热和蒸发。电势加速热发射电子，通过电子碰撞电离使金属蒸汽电离。永磁体的磁场用于将加速的电子引导至目标的中心。这提高了过程的效率。特别但不一定，锌被用作推进剂，因为它在相同温度下与其他金属相比具有更高的蒸气压。这意味着锌的蒸发需要较低的温度。为了证明我们的概念，一个 10.3 ± 0.7 μN、功率为 26.2 ± 0.7 W 的离子推进器被构造为原型。它的质量小于500克，直径为50毫米。加速电位为1 kV。尽管尚未开发出优化设计，但我们首次证明了构建金属离子推进器的可行性。这是一个新的设计空间和使用金属推进剂的未探索方法。