Determination of Band Oscillator Strengths of Atmospheric Molecules from High Resolution VUV Cross Section Measurements

真空紫外吸收截面 大气中重要分子硝酸的测量 氧化物和分子氧将与最近的 构建的VUV傅里叶变换光谱仪是唯一的， 实现了所需的非常高的分辨率 分子绝对吸收截面的测定 具有明显的旋转结构。 在175-205 nm的光谱区， 进入大气的辐射是由 分子氧和某些组分的Schumann-Runge带 透射的辐射可用于光解离NO， 低于192 nm的谱带。 一氧化氮的横截面 在低于192 nm的波长下测量。 分子氧 将在波长区域175-180 nm处的Schumann-Runge带线较尖锐。 在平流层中，赫茨伯格连续谱中的光解离 在光谱区域200-240 nm，成为主要路径， 分子氧离解 在242 nm以上， 与赫茨伯格连续谱直接相关的谱带， 非常锋利。 Herzberg I的吸收截面 在300 K的温度下将得到带， 振子强度将由直接积分确定 的绝对横截面。

Vacuum Ultraviolet (VUV) absorption cross section measurements of the atmospherically important molecules nitric oxide and molecular oxygen will be performed with a recently constructed VUV Fourier transform spectrometer that is unique in achieving the very high resolution necessary for the determination of absolute absorption cross sections of molecular bands possessing distinct rotational structure. In the spectral region 175-205 nm, the penetration of solar radiation into the atmosphere is controlled by the absorption of the Schumann-Runge bands of molecular oxygen and some fraction of the transmitted radiation is available to photodissociate NO in bands below 192 nm. The nitric oxide cross sections will be measured in the wavelength below 192 nm. The molecular oxygen cross section will be measured in the wavelength region 175-180 nm where the lines of the Schumann-Runge bands are sharp. In the stratosphere, photodissociation in the Herzberg continuum in the spectral region 200-240 nm, becomes the principal path for molecular oxygen dissociation. Above 242 nm, the Herzberg I bands, which are directly related to the Herzberg continuum, are very sharp. The absorption cross sections of the Herzberg I bands will be obtained at temperatures of 300K and the band oscillator strengths will be determined by the direct integration of the absolute cross sections.