抄録
Photoabsorption current is measured under vacuum ultraviolet irradiation between wavelength range of 170nm to 110nm. The current is appreciable at the wavelength of shorter than 160nm. The current increases at 132nm that is the ionization wavelength of NO gas and further increase of the current arises at 127nm that is the dissociation wavelength of N2.
From the facts of above mentioned and the other experimental results, photoionization and photoabsorption processes of the air are discussed here with attention to behavior of N2 and O2 that are the principal ingredient of the air.
As a result, main processes of photoionization of the air are supposed as follows. N2 is dissociated to N by absorption and N is oxidized to NO. Then, NO is ionized by vacuum ultraviolet. It is found that the ionization process of created NO is mainly single-photon process but multiphoton process is negligible in this case.
