HIGH TAPEPATURE GAS KINETIC STUDY OF NITROUS OXIDE DECOMPOSITION PERFORMKD WITH A SHOCK TUBE AID QUADRUPOLE MASS-FILTER

A quadrupole mass-filter was built and coupled to a shock tube in or-der to study high temperature gas kinetics. The chemical kinetics of the decomposition of nitrous oxide was studied with this apparatus in order to establish the mechanism of the reaction at temperatures above?N°K. Several instrumentation problems unique to shock tube mass-spectrometry were solved. The most serious problem, that of a rapid-pumping ion source, was overcome by the design and construction of an unusually thin ion source. The thermal decomposition of nitrous oxide was studied by shock-heating a mixture of 4 $ N2 0 in argon and monitoring the ion currents corresponding to all of the principal species involved in the reaction: N2 0, N2, 02, NO, and 0. In each run with the shock tube, the mass-filter was tuned to follow the conceutration of a single species. Because enough runs were made with all of the species, a run for each species at the same temperature was made for several temperatures. The results of all of the experiments are listed bellow. 1. The mechanism of the N2 0 decomposition between 1500°-25000 K is (la,b) N20 + M k N2 O+ M k-1 112 0 * N2 + 0 (2) 0 + N2 0 k,2 H + 02 (3) 0 + N20- *2110 Sk.