Aerosol Mass Spectrometer for Aircraft Sampling using Time-of-Flight Mass Spectrometry

Aerosol particles play an important role in visibility, acid deposition, climate, and human health, although large uncertainties remain in quantifying their impacts which depend on their chemical composition and atmospheric transformations. An innovative aerosol mass spectrometer (AMS)has been recently designed to fill a critical need for size-resolved, quantitative chemical composition data on aerosol particles. An aircraft version of this instrument that meets the size, weight, ruggedness, and time resolution requirements for aircraft operation has been deployed aboard ONR's CIRPAS Twin Otter research aircraft. That instrument utilized a quadrupole mass spectrometer for species detection. We propose to build a new version of the AMS that incorporates a time-of-flight mass spectrometer and upgraded sampling and vacuum components to improve detection sensitivity which is critical for aircraft measurements in clean environments. This effort also includes hardware and software developments to improve autonomous aircraft operation. A new instrument will be delivered to CIRPAS and will enable chemical composition measurements on an individual particle by particle basis.