Pressure dependency of the NF3-H2transverse-discharge pulse-initiated HF chemical laser

The pressure dependency of the performance of the NF
3
-H
2
chemical-laser system has been evaluated. The laser energies at various chemical compositions and initiation discharge energies are presented as functions of Pressure. Overall efficiency, laser pulsewidth, and effects of additive gases are also presented. For all compositions the laser energy maximized at a pressure
P_{\max}
which was observed to be dependent on the pulsewidth of the initiation discharge. At pressures below
P_{\max}
the laser energy was proportional to the partial pressure of NF
3
or H
2
. No change in slope of the laser energy versus pressure curve was observed in going from low-pressure nonexploding regimes to high-pressure exploding regimes, implying that the reactions causing the explosion did not contribute to the lasing. Lasing usually occurred in two peaks, the first containing
HF(V=2) \rightarrow HF(V=1)
lines and the second containing
HF(V=3) \rightarrow HF(V=2)
and
HF(V=1) \rightarrow HF(V=0)
lines. These data indicate that lasing is due to the reaction sequence: 1)
NF_{3} + e^{-} = \cdot NF_{2} + F\cdot + e^{-}; 2) F\cdot + H_{2} = HF+(V) + H\cdot
; and 3)
HF+(V) + h\nu = HF+(V-1) + 2h\nu
.