无负电性填充气体条件下负离子气体时间投影室的运行
Operation of a negative ion gas time projection chamber without electronegative fill gases
浏览论文内容
中文总结 AI 辅助
本研究提出利用常规填充气体CF$_4$通过解离电子附着产生负离子的新方法，实现低扩散漂移，增益与电子雪崩相当，并通过单离子计数提高能量分辨率，适用于暗物质探测等稀有事件搜寻。
中文摘要 AI 辅助
微图案气体时间投影室中粒子径迹的高保真重建使该技术成为未来稀有事件搜寻（包括方向灵敏暗物质实验）的理想选择。此类实验通常需要较大的漂移距离，因此整体空间分辨率受扩散限制。负离子漂移比电子漂移具有更低的扩散，因此是实现大规模探测器的有吸引力的选择。使用负电性气体产生负离子会带来技术挑战，最显著的是与常规气体混合物相比增益降低。在本研究中，我们展示了一种通过解离电子附着利用常规分子填充气体CF$_4$产生负离子的新方法。我们对负离子漂移的光学测量表明，电子附着长度小于1毫米，且增益与电子雪崩相当。单个负离子雪崩也被时间分辨，从而能够计数到达读出端的离子数量。我们测量到，与在相同增益条件下测量的集成电子雪崩信号相比，通过单离子计数实现了改进的能量分辨率。
英文摘要
The high fidelity reconstruction of particle tracks in micropatterned gaseous time projection chambers renders this technology ideal for future rare-event searches, including direction-sensitive dark matter experiments. Large drift distances are typically required for such experiments, so that the overall spatial resolution is limited by diffusion. Negative ion drift exhibits lower diffusion than electron drift and is thus an attractive option for realising a large-scale detector. The use of electronegative gases to create negative ions introduces technical challenges, most notably a reduction in gain when compared to conventional gas mixtures. In this study, we demonstrate a new method for negative ion generation via dissociative electron attachment using the conventional molecular fill gas CF$_4$. Our optical measurements of negative ion drift indicate electron attachment lengths of $<$1 mm and comparable gain to electron avalanches. The individual negative ion avalanches were also time-resolved, allowing the number of ions reaching the readout to be counted. We measure an improved energy resolution by single ion counting, relative to an integrated electron avalanche signal measured under identical gain conditions.
发表机构
- The Australian National University（澳大利亚国立大学）
- University College London（伦敦大学学院）
机构由 AI 辅助整理，请以论文原文为准。
