Moreover, in order to measure the positions of both positron and electron in the IP at the same time, two special BPMs with 8-button electrodes will be installed at the both side of interaction point.

• 此外，为了同时测量对撞点处正、负电子束的位置，两套带有8电极的特殊束流位置探测器(BPM)将安装在对撞点两侧。