Document Type


Journal/Book Title/Conference

Intermountain Graduate Research Symposium


Logan, UT (USU Campus)

Publication Date


Award Number

NASA, National Aeronautics and Space Administration NNX09AH97G

Funding Agency

NASA, National Aeronautics and Space Administration

Faculty Mentor

Mike Taylor


The mesosphere-lower thermosphere (MLT) is perhaps the least understood region of the earth’s atmosphere due to the difficulty of obtaining in-situ measurements. Access to the MLT is limited to high-speed sounding rockets for brief periods of at most a few minutes. Because of its wide mass range and high scan rate, Time-of-flight mass spectrometry (TOF-MS) has potential to resolve thin layers of diverse species in the MLT. However, because ambient pressures can reach into the millitorr range, TOF-MS has rarely been applied in the MLT due to its dependence on high voltages and microchannel plate (MCP) detectors. A novel dual mode, compact axial TOF-MS suitable for deployment aboard a sounding rocket for measurements in the MLT is presented. This TOF-MS is capable of operating in either a standard TOF mode or in a multiplexing mode to achieve high measurement duty cycles with a theoretically unlimited mass range. Experimental data is presented demonstrating successful MCP operation in a variety of environments including O2, N2, and air at pressures into the low millitor range. Also presented are results from extensive simulation and modeling efforts to approximate the in-flight operating environment of the TOF-MS. Gas flow modeling in a typical MLT environment is performed using the Direct Simulation Monte Carlo (DSMC) method. Standard gas flow equations are combined with DSMC results to estimate pressures inside the TOF-MS. Modeling, simulations and experimental work combine to demonstrate the potential of the new dual mode TOF-MS for deployment in the upper atmosphere.


Poster presented at Intermountain Graduate Research Symposium in 2011.

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Physics Commons