Demonstration of a Multi-Layer, Lithographically Manufactured Plasma Spectrometer

Development of new plasma instruments is needed to enable constellation- and small satellite-based missions. Key steps in the development pathway of ultra-compact plasma instruments employing lithographically patterned wafers are the implementation of layer-to-layer electrical interconnects and demonstration of massively parallel measurements, that is, simultaneous measurements through multiple identical plasma analyzer structures. Here we present energy resolved measurements of electron beams using a 5-layer stack of wafer-based, energy-per-charge, electrostatic analyzers. Each layer has eight distinct analyzer groups that are comprised of multiple micron scale energy-per-charge analyzers. The process of fabricating the electrical interconnects between the layers is described and the measured energy resolution and the angular resolution compared to theoretical predictions. The measurements demonstrate successful operation of 400 micron scale analyzers operating in parallel. Spacecraft are expensive and difficult to build. CubeSats, a class of small, inexpensive spacecraft are being used for scientific missions. However, standard instruments to measure the local plasma environment cannot fit on such small spacecraft. Here we describe a new type of space plasma instrument that is manufactured with processes similar to how computer chips are made. These plasma instruments are made by stacking layers of micro-scale plasma analyzers to create a larger instrument with a significant geometric factor. Each layer includes nearly one hundred small energy-per-charge plasma analyzers working in parallel. Initial measurements from a 5-layer instrument along with the processes used to build the instrument are described in this work. Microscale plasma energy analyzer demonstrated in laboratory testsLithographic fabrication process enables low voltage analysis of charged particles up to tens of keV/chargeMulti-layer instrument required development of a novel fabrication process