MIT News July 27, 2022
Researchers at MIT designed, fabricated and characterized digitally manufactured, compact retarding potential analyzers (RPAs) multi-electrode instruments that can be used as in-orbit mass spectrometers and as on-ground/in-orbit ion energy analyzers. The RPA electrode housing, which is the most critical component of the RPA, was additively manufactured in a printable glass-ceramic via vat polymerization, resulting in non-porous, high-temperature compatible, and high-vacuum compatible hardware. Four different RPA designs were synthesized to probe the ionosphere (design with floating grid alignment at the aperture level) and laboratory plasmas (designs with floating grid aperture alignment at the cluster level). Simulations showed that the RPA design that enforces floating grid aperture alignment at the aperture level attains the best performance, although RPA designs that implement floating grid aperture alignment at the cluster level are more resilient to grid misalignment. Experimental characterization of the RPAs using an ion source and a helicon plasma source is consistent with expected performance and the literature. Plasmas with a Debye length as small as 50 µm were successfully characterized using the reported sensors, matching the performance of state-of-the-art RPAs manufactured via semiconductor microfabrication…read more. Open Access TECHNICAL ARTICLE
Experimental results of testing RPA-215 design in a helicon plasma source… Credit: Additive Manufacturing, 13 July 2022, 103034