Improved Lunar Regolith Simulant Ion Implantation

Researchers and other technology developers require regolith simulants that accurately emulate the properties of lunar, Martian, and asteroid soils to ensure that the processes, devices, tools, and sensors being developed will be usable in an active mission environment. To move toward higher fidelity regolith simulants, NASA has developed a system that takes typical regolith simulants and implants ions of relevant elements to better simulate the conditions of extraterrestrial soils. The ion implantation device developed here is composed of three key elements as shown in the figure below: two hopper and rotary valve elements and the acceleration grid structure. To perform the ion implantation, the system is first placed within a vacuum chamber, pumped down, and gases of the elements of interest are pumped into the chamber. The system then first passes a mass of granulated lunar regolith simulant through two stages of hoppers and rotary valves to condition the material. Key to the system is a process for interstitial gas removal (a source of contamination) as shown in the figure on the right. After conditioning, the regolith simulant is passed between two parallel electrodes under a high voltage, accelerating ions of the process gas and implanting those ions within the regolith simulant at controllable depths. The related patent is now available to license. Please note that NASA does not manufacturer products itself for commercial sale. The production of high-fidelity extraterrestrial regolith simulants is important for the development of future in-situ resource utilization (ISRU) and remote sensing technologies. For these materials, the mechanical properties can be readily replicated but the absorbed material, electrostatic, and dielectric properties of lunar, Martian, or asteroid regolith can be difficult to simulate. Innovators at the NASA Kennedy Space Center have developed a methodology and system that can implant helium, hydrogen, and other ions in regolith simulants to emulate the exposure of the simulated regolith to phenomena like solar winds. The system has been successfully prototyped and demonstrated to implant helium ions in simulated regolith and advancements in the material processing have led to low levels of contaminants in the regolith. The ion implanted regolith may be used to develop advanced ISRU, in-space mining, and remote sensing technologies.