First Flight and Redesign of the Thermal Ion Gated Time of Flight (TIGTOF)

The escape of atmospheric particles at high latitudes is a well documented process called ion outflow. On Earth, outflowing O+ is most commonly observed, followed by significant populations of heavier molecular (e.g. N2+) ions. Although we can measure upflow on Earth, we lack the basic data necessary to fully understand the role that differing ion masses play in the upflow process. The Thermal Gated Ion Time of Flight (TIGTOF) is being developed to measure in-situ particle fluxes in the cusp-region ionosphere, and will allow us to examine the role of molecular ions in the ion upflow process, and ultimately provide a proper characterization of the energy budget as input to ionosphere-thermosphere coupling models. At this stage, a prototype of TIGTOF has been flown on an ionospheric sounding rocket. Analysis of this flight data is being used to guide the redesign process for an improved version of TIGTOF, i.e. to distinguish between O+ and N2+ ions at sounding rocket altitudes. Additionally, particle tracing methods are being employed to optimize the geometric factor for the improved instrument.