Date of Award
Doctor of Philosophy (PhD)
The Nano-Dust Analyzer (NDA) instrument is developed for the detection and compositional analysis of nanometer-sized dust particles originating near the Sun, and delivered near Earth’s orbit by radiation pressure and electromagnetic forces. These particles report on processes occurring close to the Sun. This thesis investigates the basic dynamical processes and the results of the numerical calculations are then used to design and optimize the NDA, a linear time-of-flight mass analyzer. The challenge of needing high sensitivity of detection while pointed close to Sun’s direction is solved by optimizing the instrument’s field-of-view, pointing requirements, and designing an internal baffle system to suppress the effects of solar-ultraviolet radiation.
Little is known about the origin, distribution and fate of dust particles in the inner Solar System. The interplanetary dust complex is fed mostly by comets and asteroids. The interplanetary dust particles are transported towards the Sun (on timescales of ~ thousands of years) where they undergo multiple processes: most are destroyed by the heat of the Sun or sputtering by solar wind particles, while a small fraction is expelled out of the Solar System. Grinding from mutual collisions alters their size distribution, which intensifies closer to the Sun, where their density increases. These particles influence the solar wind plasma, being one of the sources of inner source pickup ions, or mass loading the expanding solar wind. The importance of these effects is yet to be fully understood.
The population of particles expelled from the Solar System include submicron-sized dust particles known as β-meteoroids, which are accelerated by solar radiation pressure. Nanometer-sized particles also belong to this population and are picked up and accelerated to high velocities by the solar wind. There is likely a wealth of information in their mass distribution, composition and dynamical properties, including their temporal and spatial flux variations, which is influenced by their interaction with the solar wind. Past missions have identified and partially-characterized particles originating from the inner Solar System. This thesis lays the foundations for providing measurements to resolve outstanding science questions by presenting a concept for their detection and a basic design for a capable instrument.
O'Brien, Leela Elise, "The Nano Dust Analyzer for the Detection and Analysis of Nanometer-Sized Particles from the Inner Heliosphere" (2017). Aerospace Engineering Sciences Graduate Theses & Dissertations. 225.