Time resolved spectroscopy using the shock tube characterisation and calibration
The main objective of this work was the development of the existing shock tube system so that it could be used for kinetic investigations. As a result of the many modifications and alterations to the shock tube, and thorough and successful characterisation experiments, the shock tube is now considered to be suitable for the study of high temperature gas phase reactions. One of the important features of the characterisation experiments was the dependency of several shock parameters (P2(expt), P5(expt), and Mr) on the initial test gas pressure in the shock tube. Shock parameters have been determined which take into account non-ideal behaviour such as side wall boundary layer formation. The atomic resonance absorption spectroscopy (ARAS) detection technique was only installed during the latter stages of this work, and due to time restrictions is not yet fully operational. When this is achieved the shock tube at Aberdeen will be the only shock tube in the U.K. where time resolved, gas phase reactions, can be kinetically investigated. Results from Brookhaven National Laboratory, New York, are presented where a similar shock tube - ARAS system was calibrated for atomic oxygen. Nitrous oxide (N2O) was used as a clean source of O atoms, and the bimolecular rate expression for the reaction: N2O + M N2 + O + M. over the temperature range 1266 T(K) 2311 was determined to be: k (cm3molecule-1s-1) = (1.220.19)x10-9 exp (-57861600 cal/RT). This rate expression is in good agreement with literature values.