Knowledge Bank

The self-broadened halfwidths and pressure shifts o water have been obtained using the McMath Fourier transform spectrometer at Kitt Peak National Observatory/Solar National Observatory. Over 1200 vibration-rotation transitions involving the pure rotational and $\nu 2$ bands of the main isotope have been measured at room temperature up to $J=17$ and $Ka=9$. The widths range from 0.52 to $0.1cm-1/atm$ and the pressure shifts from $+0.05to-0.05cm-1/atm$. Additional measurements of isotopic transitions reveal no detectable differences for the widths of the three main isotopes of water vapor.