关键词: 光谱学, 电离光谱, 电子激发, 大气辐射, 高空大气

Abstract: The charge exchange and the energy transfer between Earth's upper atmosphere and highenergy electrons play an important role in the upper atmospheric luminous phenomena such as aurora and airglow. By building a ground-based simulating setup for electron excited high-altitude atmospheric radiation based on a vacuum system, the ionizing excitation of neutral molecules induced by electron impact and the corresponding radiative transition mechanism in the upper atmosphere are verified here. The device can create a vacuum gradients of more than 5 orders from 102 to 10-3 Pa, generate electrons with kinetic energy in 102-103 eV and monitor spectral transitions with wide range from near ultraviolet to near infrared. As an illustrated example, the setup has been applied to study the electron excitation of N2 and O2, the two main components of atmosphere, and their spectral distributions are measured and compared. It's found that the emission spectral intensity of N2 is not only positively correlated with electron energy, but also much higher than that of O2 under the same condition. Using the known spectral bands of the pure gases of N2 and O2, the excited spectrum of the actual atmosphere has been assigned, which shows that the emission bands of the air and pure N2 tend to be convergent, but the former's intensity decreases in some contents. These results demonstrate that the developed setup can be used to simulate the colliding excitation of middle and upper atmosphere components during the deposition of high-energy electrons.

Key words: spectroscopy, ionization spectrum, electron excitation, atmospheric radiation, upper atmosphere