TA5 - H2/F2flame propagation and repetitively pulsed hydrogen flouride (HF) chain-reaction chemical laser

The burning velocity and the nature of the H
2
/F
2
flame at various gas compositions gas compositions have been experimentally determined. It was found that reactions induced by a diffusion-type flame proceed rather slowly, but reactions triggered by a compression wave proceed with supersonic speed. Based on the measurements of gas stability, repetetive pulse operation of H
2
/F
2
chemical lasers at atmospheric pressure has been achieved. The second and third explosion limits of H
2
+ F
2
reactions in O
2
/He mixtures were also studied experimentally to improve our understanding of the nature of H
2
+ F
2
explosion. The apparatus allowed the simultaneous time-resolved measurement of both gas pressure and temperature at the center of the spherical reaction vessel. It was found that, for fixed H
2
+ F
2
total pressure and O
2
concentration, mixtures with higher F
2
/H
2
ratios are less stable and explode at a lower temperature. It appears quite certain that molecular O
2
plays an important role in the chain termination reaction. However, the addition of CF
4
, SF
6
, or N
2
showed no effect on the boundaries of the H
2
/F
2
explosion.