Author/Authors :
Zalicki، نويسنده , , P. and Ma، نويسنده , , Y. and Zare، نويسنده , , R.N. and Wahl، نويسنده , , E.H. and Dadamio، نويسنده , , J.R. and Owano، نويسنده , , T.G and Kruger، نويسنده , , C.H.، نويسنده ,
Abstract :
Cavity ring-down spectroscopy has been used to measure the absorbance of methyl radicals near 216 nm. The methyl radicals are generated by a hot tungsten filament heated to 2300 K in a mixture of 0.5% CH4 in H2 slowly flowing through the reactor at 20 Torr total pressure. CH3 absorbances are detected with a noise-equivalent sensitivity of two parts in 105 using a narrow pencil of UV light 0.5 mm in diameter, which allows measurement of spatial profiles of CH3 for column densities of 3×1012 radicals/cm2 (3×1012 radicals/cm3×1 cm absorption pathlength).
