A negative ion micro time projection chamber (NI$\mu$TPC) was developed and its performance studied. An NI$\mu$TPC is a novel technology that enables the measurement of absolute $z$ coordinates for self-triggering TPCs. This technology provides full-fiducialization analysis, which is not possible with conventional gaseous TPCs, and is useful for directional dark matter searches in terms of background rejection and the improvement of the angular resolution. The developed NI$\mu$TPC prototype had a detection volume of 12.8 $\times$ 25.6 $\times$ 144 mm$^{3}$. The absolute $z$ coordinate was determined with a location accuracy of 16 mm using minority carrieres of SF$_{5}^{-}$. Simultaneously, there was a successful reconstruction of the three-dimensional (3D) tracks with a spatial resolution of 130 $\mu\rm{m}$. This is the first demonstration of 3D tracking with the detection of absolute $z$ coordinates, and it is an important step in improving the sensitivity of directional dark matter searches.

中文翻译：

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用于定向暗物质搜索的SF6气体负离子微型TPC探测器的研制

开发了负离子微时间投射室（NI$\mu$TPC）并对其性能进行了研究。NI$\mu$TPC 是一种新技术，可以测量自触发 TPC 的绝对 $z$ 坐标。该技术提供了全基准分析，这是传统气态 TPC 无法实现的，并且在背景抑制和角分辨率提高方面对于定向暗物质搜索很有用。开发的 NI$\mu$TPC 原型的检测体积为 12.8 $\times$ 25.6 $\times$ 144 mm$^{3}$。绝对 $z$ 坐标是使用 SF$_{5}^{-}$ 的少数载流子以 16 毫米的定位精度确定的。同时，成功地重建了空间分辨率为 130 $\mu\rm{m}$ 的三维（3D）轨迹。