The Source Function Changed within Layers and the Self-Reverse of Prominence Line

It is known thal the self-reverse of prominence line is related to the change of the source function. In this paper, the source function changed within three layers has been used to probe the relation between the changing forms of the source function and the self-reverse of prominence line. It is found thal:(1) the source function of self-reverse in Ha lines increases toward the center of prominence, and the source functions in center are in theory 1.0-∞ times those on the boundary: (2) when the total optical depth at line center is not very t.iick. the self-reverse can not appear, although the source function increases toward the center of prominence: (3) with the increase of τ_λ0 and K, the profile variations follow such an order: shallow self-reverse and deep self-reverse.