For a microwave discharge nitrogen plasma with its discharge pressure about 1 Torr, our OES measurement showed that the rotational temperature of N+2 B state by the first negative system (1NS) is about 1.5 times higher than that of N2 C state by the second positive system (2PS). Meanwhile, it is found that the rotational temperature of O+2 b state by 1NS is almost the same as that of O2 b state by the atmospheric absorption band, which is quite different from N2 plasma. We consider that the rotational temperature of the ground state O+2 X ion should be higher than that of O+2 b state due to difference in the internuclear distance, where that of the O+2 b state is much larger than that of the ground state O+2 X. The angular momentum of both X and b states are almost conserved before and after the electron impact excitation due to small mass of an electron. Therefore, the rotational temperature of the X state of O+2 ion should be estimated to be about 1.3 times of that of O+2 b state. This value gives a similar result with that of nitrogen plasma, where the internuclear distances of B and X states of N+2 are almost the same. It is considered that the ground-state molecular ion has higher rotational temperature than neutral molecule.
各種検索
サポート
ヘルプ