THE APPLICATION OF THE QUICKEST DESCENT METHOD TO THE ANALYSIS OF THEH-ALPHA-LINE IN LOOPS

The quickest descent method and the multi-layer model are proposed to analyse symmetrical and asymmetrical line profiles of loops in this pa per. By fitting observed lines, the physical parameters such as Dopple r width, DELTAlambda(D), the optical thickness at line centre, tau(lam bda)0, and the line displacement, DELTAlambda(0), can be directly obta ined. Using this method, some symmetrical and asymmetrical line profil es of both the loop prominence on February 18, 1984 and the loop on Au gust 17, 1989 are fitted. It is found that the method mentioned in thi s paper is characterized by rapid convergence, high precision, and les s scatter.