Knowledge Bank

Measurements of strength, line position, and width were performed for rotational lines corresponding to the $(0310,1110)\Pi$ to $0001$ vibrational transition in $N2O$. These measurements constitute the first recording of such transitions in this species. A tunable diode laser operating in the 21 $\mu m$ spectral region was used as source. A White type cell with a path length of up to 100 meters contained the gas sample. A blocked impurity band (BIB) silicon detector refrigerated with liquid $\mathrm{<mrow\; data-mjx-texclass="ORD">4</mrow>}He$ was used as a detecting element. Combination of fast sweep averaging and second derivative detection were applied to observe these low strength transitions. However, line strengths were determined by direct absorption measurements, which yielded absolute intensities. Characteristics of the measured spectra obtained at several temperatures, as well as details of the technique, will be presented. J. M. Sirota holds a National Research Council - NASA Research Associateship.""