Measurements of Ultraviolet Absorption Cross Sections of NO2 at Various Pressuresand Temperatures

摘要

An account is given of progress towards the measurements of absolute, ultraviolet cross sections of NO2 during the ten-month period 10/1/93-7/31/94. The accomplishments include: (a) construction of an absorption cell; (b) construction of vacuum system; (c) the assembly of an optical system including focusing of a 6.65 m spectrograph; (d) obtaining high resolution photographic spectra of NO2 in absorption; and (e) the first measurements of cross sections of NO2 at 295 K. The high resolution absorption spectrum of NO2 has been obtained from National Research Council of Canada. The high resolution cross sections of NO2 at 295 K have been measured photoelectrically in the wavelength region 390-452 nm. No pressure dependency has been observed. The absolute cross section scale agrees with published values, but there are large wavelength shifts in earlier works.