论文标题
扩散对在LARTPC中观察到的能量损失的峰值的影响
Effect of Diffusion on the Peak Value of Energy Loss Observed in a LArTPC
论文作者
论文摘要
液体氩时间投影室（LARTPC）检测器观察电离电子以测量带电的颗粒轨迹和能量。在LARTPC中，产生电离和收集时的长时间（$ \ sim $ ms）意味着扩散可以通过与探测器的空间分辨率相当的金额涂抹电荷，这是由电荷感应通道之间的间距给出的（$ \ sim $ mm）。该涂抹对每个通道测量的能量损失的分布有影响。特别是，涂抹增加了每个通道观察到的带电粒子轨迹的长度，因此增加了该通道记录的粒子能量损失的最概要值（MPV）。例如，我们发现这种效果会在2毫秒漂移时间和4.7 mm的电线间距上移动MUON的MPV $ de/dx $，其能量为1 GEV，$ {\ sim} 4 $％，如Dune-Fd Lartpc所示。这对LARTPC中的能量尺度校准和电子寿命测量有影响，这两者都将MUON能量损失分布的MPV用作“标准蜡烛”。评估了扩散对这些校准的影响。
Liquid Argon Time Projection Chamber (LArTPC) detectors observe ionization electrons to measure charged particle trajectories and energy. In a LArTPC, the long time ($\sim$ms) between when the ionization is produced and when it is collected means that diffusion can smear the charge by an amount comparable to the spatial resolution of the detector, given by the spacing between charge sensing channels ($\sim$mm). This smearing has an impact on the distribution of energy losses measured by each channel. In particular, the smearing increases the length of the charged particle trajectory observed by each channel, and therefore the most-probable-value (MPV) of particle energy loss recorded by that channel. We find, for example, that this effect shifts the MPV $dE/dx$ of a muon with an energy of 1 GeV by ${\sim}4$% for a 2 ms drift time and 4.7 mm wire spacing, as in the DUNE-FD LArTPC. This has implications for the energy-scale calibration and electron lifetime measurements in a LArTPC, which both use the MPV of the muon energy loss distribution as a "standard candle". The impact of diffusion on these calibrations is assessed.
