Absolute Cross Section Measurements for the Production of NIand NII Fluorescense through Photoexcitation on N 2

这笔赠款支持测量从各自的阈值到200A的氮光解离激发产生NI 120 nm发射的荧光截面的工作。这样的横截面对于准确的定量分析和评估地球氮白天发光模型是必需的。拟议的NI120 nm测量工作将利用现有仪器进行，该仪器由本小组开发，用于南加州大学的光源和威斯康星大学同步辐射设施的同步辐射光源。NII测量需要一台光谱带宽为10A的小型SEYA-纳米冈型单色仪。希望还可以测量用于产生(1)来自氮气的NI 113.4、142.1、149.3和174.3 nm发射以及(2)来自O2的OI 130.4和OI 135.6 nm、以及来自O2的OI102.5 nm的截面函数。

This grant supports work to measure the fluorescence cross sections for producing the NI 120nm emission from photodissociative excitation of N2 from their respective thresholds to 200A. Such cross sections are required for accurate quantitative analysis and for assessments of models of the Earth's nitrogen dayglow. The proposed work on the NI 120nm measurements will be carried out with existing instrumentation which has been developed by the present group for use with light sources at USC and the synchrotron radiation source at the University of Wisconsin Synchrotron Radiation Facilities. A small Seya-Namioka type monochromator with a spectral bandwidth of 10A is required for the NII measurements. It is hoped that it will also be possible to measure the cross section functions for producing (1) the NI 113.4, 142.1, 149.3, and 174.3nm emissions from N2 and (2) the OI 130.4 and OI 135.6nm, and OII 102.5nm from O2.