The far infrared polarimeter–interferometer system (POLARIS) on the Joint-TEXT has been upgraded recently. A new support structure has been applied to the mixer array of the POLARIS for adjusting the position of the mixers precisely. Five detection chords have been added to the system on the low field side by optimizing the utilization efficiency of the laser beams on both sides of the beam splitting grid. The spatial resolution can be improved from 3 to 1.5 cm. A better measurement on plasma electron density and current density has been obtained after the system is upgraded. The initial experimental result will be introduced along with the upgrade details.

中文翻译：

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Joint-TEXT上远红外三波偏振计-干涉仪系统的升级

Joint-TEXT 上的远红外偏振计-干涉仪系统（POLARIS）最近已升级。POLARIS的混频器阵列采用了新的支撑结构，可以精确调整混频器的位置。通过优化分束栅两侧激光束的利用效率，系统在低场侧增加了五个检测弦。空间分辨率可以从 3 厘米提高到 1.5 厘米。系统升级后获得了更好的等离子体电子密度和电流密度测量结果。初步实验结果将与升级细节一起介绍。