Anisotropic diffusion of electrons in liquid xenon with application to improving the sensitivity of direct dark matter searches
Anisotropic diffusion of electrons in liquid xenon with application to improving the sensitivity of direct dark matter searches
复制标题
液态氙中电子各向异性扩散及其应用于提高直接暗物质搜索的灵敏度
DOI：
10.1016/j.nima.2011.01.089
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发表时间：
2011
影响因子：
1.4
通讯作者：
P. Sorensen
中科院分区：
文献类型：
--
作者：
P. Sorensen
最近，液体氙气时间投影室中的电子扩散被用来从电子信号的宽度推断粒子相互作用的z坐标。该技术的目的是通过区分边缘事件和大宗事件来降低背景事件的发生率。对使用它的暗物质搜索数据的分析将受益于纵向电子扩散的增加。我们表明，如果外加电场减小，预计会有显著的增加。这一观察结果执行起来微不足道，但与传统智慧和实践背道而驰。我们还提取了纵向扩散系数的第一次测量，并证实了电子在液体氙气中的扩散在典型操作条件下是高度各向异性的预期。
Electron diffusion in a liquid xenon time projection chamber has recently been used to infer the z coordinate of a particle interaction, from the width of the electron signal. The goal of this technique is to reduce the background event rate by discriminating edge events from bulk events. Analyses of dark matter search data which employ it would benefit from increased longitudinal electron diffusion. We show that a significant increase is expected if the applied electric field is decreased. This observation is trivial to implement but runs contrary to conventional wisdom and practice. We also extract a first measurement of the longitudinal diffusion coefficient, and confirm the expectation that electron diffusion in liquid xenon is highly anisotropic under typical operating conditions.