The first results from HIRAC - the Highly Instrumented Reactor for Atmospheric Chemistry
Abstract
The Highly Instrumented Reactor for Atmospheric Chemistry, HIRAC, is a recently commissioned stainless steel environmental chamber. Uniquely, the structure allows for simultaneous temperature and pressure variation and for the monitoring of radical species by Fluorescence Assay by Gas Expansion (FAGE) and Cavity Ring Down Spectroscopy (CRDS). HIRAC is cylindrical in shape with internal dimensions of 2.0 m long and 1.2 m diameter giving a total volume of ~2.25 m3. It is fitted with a broad range of instrumentation based on different detection techniques (detailed in the table below) to allow accurate monitoring of the chemistry occurring inside the chamber. Light for photochemical studies is be provided by lamps housed in eight quartz tubes mounted radially inside the reactive volume parallel to the chamber's principle axis providing a homogenous radiation profile. In this paper we present example of work relating to the three major objectives for HIRAC: 1) Mechanism development linked to the Master Chemical Mechanism - Measurements of pressure dependent OH and HO2 yields from the reaction of O3 with trans-2-butene and isoprene. 2) Field instrument development and calibration - Development of a CRDS system for measuring NO3 radicals inside HIRAC and the first pressure dependent calibrations of a FAGE HOx instrument. 3) Kinetics and Structural Activity Relationship (SAR) development - Relative rate studies of the reaction of Cl atoms with a series of acetates. The range of detection techniques employed in HIRAC and the species detected.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.A21C0206M
- Keywords:
-
- 0317 ATMOSPHERIC COMPOSITION AND STRUCTURE / Chemical kinetic and photochemical properties;
- 0394 ATMOSPHERIC COMPOSITION AND STRUCTURE / Instruments and techniques