On the Feasibility of Analyzing Ablator Blow-off Gases with a Time-of-Flight Mass Spectrometer

摘要

The subject of determining the composition of blow-off gases from rapidly heated ablators is treated entirely from the experimental point of view. The various equipment requirements are briefly described including the thermal sources for heating materials as well as the vacuum systems needed to sample the gases directly from the pyrolysis zone into the inlet of the spectrometer. Particular attention is given to the state of the art of time-of-flight (TOF) mass spectrometry. The unique abilities of the instrument as well as its limitations are assessed, and the instrumental factors which influence mass spectral patterns are carefully delineated. The equipment presently available for recording output spectra is appraised and the corresponding limitations are outlined. In addition, the subject of quantitative analysis of gaseous mixtures by mass spectrometry is reviewed with particular reference to the TOF instrument and its application to ablation-product analysis. This is extended to include an exploration into the possibilities of utilizing electronic data-computing machines to resolve complex mixture mass spectra into meaningful dhemical analysis. (Author)