Ionospheric Neutral Mass Spectroscopy

Understanding neutral masses in the ionosphere, especially in the E- and D-regions, is a very challenging endeavor. This is due to the high density of neutral masses at this height and the speed at which sounding rockets travel. These factors limit the ability to understand the quantity and quality of neutral masses in these regions; the density of these masses and the percentage of different masses present is not well resolved. Therefore, there exists a need to further investigate neutral mass in the ionosphere, and this research aims at presenting a possible instrument for doing so. We conducted experiments to evaluate whether a residual gas analyzer could be used as a neutral mass spectrometer for application in the E- and D-region ionosphere. The basic experimental configuration was a roughing vacuum pump attached to a turbo vacuum which together brought the configuration to a pressure on the order of 10-8 Torr. With the residual gas analyzer within the vacuum, data was collected on mass isolation, accuracy, and the scanning speed of the instrument. Ultimately, the residual gas analyzer was able to collect at a rate of 10 ms per amu studied with a deviation of ± 2 x 10-8 Torr when running as quickly as possible; a higher precision with deviation of ± 3 x 10-9 Torr was achieved when collection was slowed. The results supported the potential flight of a residual gas analyzer on future sounding rocket campaigns for studying neutral masses within the ionosphere.