Research & Teaching Faculty

Default Header Image

Spectroscopy of Organic Aerosols

Principal Investigator: 

In the atmosphere, gas phase species can react in or on organic particles and change the particle properties.These types of reactions are known as heterogeneous reactions, and are of interest for several reasons.Processes such as these can change the hygroscopic and optical properties of the particles, influencing their ability to scatter and absorb radiation and to act as cloud condensation nuclei.In addition, these reactions can affect the amounts of key gas phase pollutants in the atmosphere.There is also the possibility that these reactions can produce toxic or carcinogenic compounds.

ion trap

This project involves the development of a single particle mass spectrometer capable of measuring the size-resolved chemical composition of individual organic aerosols in real-time.In this instrument aerosol particles will be accelerated through an aerodynamic lens system which will collimate the particles into a well-defined beam.The aerosol beam will pass through a timing region where scattered light from two Nd:YAG lasers will be detected using separate photomultiplier tubes.The time delay between the scattered light pulses will be used to measure the velocity of individual particles and control the firing of the vaporization and ionization lasers.Vaporization, ionization, and mass analysis of each particle will be carried out in a specially designed ion trap.Vaporization with a CO2 laser will occur first, followed by near threshold ionization of the aerosol constituents using a tunable vacuum ultraviolet laser.

aerosol design