The soft X-ray coronal mass ejection above solar limb of 1998 April 23

Using the observational materials of SXT/HXT aboard satellite Yohkoh and the Nobeyama Radioheliograph (NoRH) on 1998-04-23, a comprehensive study of the soft X-ray coronal mass ejection (CME) above solar SE limb shows that there were two magnetic dipolar sources (MDSs), one magnetic capacity belt (MCB) between the MDSs, one neutral current sheet (NCS) and some rare activation sources (ASs). When the MCB was changed by the ASs to become a magnetic energy belt (MEB), both mass and energy were concentrated to form the NCS. When the MDSs were connected by the MEB, the NCS was formed and the CME occurred. Mass was ejected not only from the NCS, but also from the whole MEB. The expanding loop of the CME had the two MDSs as footpoints. The top of the loop was always inclined towards the footpoint of the weaker source, and its locus marks the NCS.