The self-reversal line of a solar prominence and its broadening mechanism

The broadening mechanism of a prominence Ha line is mainly a combination of Doppler broadening and damping broadening, and Stark broadening can be neglected. In this paper, the relationships between an H alpha self-reversal line of a solar prominence and its broadening mechanism are discussed. It is found that the characteristics of the prominence self-reversal line are not affected by any of the broadening mechanisms used, and, in general, the profile shape of the prominence H alpha line with deep self-reversal is hardly changed by any of the broadening mechanisms used. The calculated parameters, such as the distance between the two peak points of a self-reversal line and the Doppler width of the line, are changed even less, i.e. the effects of broadening mechanisms on the prominence self-reversal line are very small. For the prominence line with shallow self-reversal, however, the profile shape is changed with any of the different broadening mechanisms used, i.e, the shallow hump is obviously changed, and the calculated parameters are greatly changed.