PRESSURE AND DOPPLER BROADENING OF THE MOLECULAR ION $HCO^{+} J=0\rightarrow$1 TRANSITION AT AMBIENT AND LIQUID NITROGEN TEMPERATURES WITH $H_{2}$ AND Ar COLLISION PARTNERS

$^{1}T$. G. Anderson, C. S. Gudeman, T. A. Dixon, and R. C. Woods J. Chem. Phys. 72, 1332 (1980).Author Institution:The pressure broadening parameter $\partial\Delta\nu/\partial p$ and the Doppler line width $\Delta\nu_{DOP}$ are reported for the J= 0+1 transition of the linear molecular ion $HCO^{+}$. Previous work in this $laboratory^{1}$ measured $HCO^{+}$ collisional broadening by $H_{2}$ at 100 K using a free-running klystron source, while the present experiments employ a phase lock stabilized Klystron, the frequency of which is digitally swept by a computer. Improvements in sensitivity have allowed the present work to be extended to include Ar as the collision partner and broadening at ambient temperatures