Gain distribution, population densities and rotational temperature for the (00°1)-(10°0) rotation-vibration transitions in a flowing CO2-N2-He laser

Small-signal gain coefficients in a flowing amplifying mixture of CO
2
-N
2
-He were measured on 46 individual rotation-vibration transitions in the
P
and
R
branches of the
(00\deg1)-(10\deg0)
band in CO
2
. The resulting gain distribution as a function of
J
was in agreement with a Boltzmann distribution of population among the rotational levels of each vibrational state. The physical parameters characterizing the CO
2
laser levels were found to be
\frac{N_{00\deg1}}{N_{10\deg0}} = 2.27; \frac{N_{00\deg1}}{N_{total}} \geq 0.17
;
\frac{N_{10\deg0}}{N_{total}} \geq 0.08; T = 340\deg
K where N
total
is the number of CO
2
molecules in the amplifying medium. The operating mixture was characterized by the following partial pressures and flow velocity: p(CO
2
) =0.65 torr; p(N
2
) =1.40 torr; p(He) =2.9 torr; v=192 cm/s.