论文标题
Belle II实验的硅顶点检测器
The Silicon Vertex Detector of the Belle II Experiment
论文作者
论文摘要
自2019年春季摄入数据以来，Superkekb对撞机（日本Kek）Belle II硅顶点探测器（SVD）一直可靠地运行，并且具有高效率，同时提供了高质量的数据：高信噪比，高噪声比率，大于99％的命中效率，效率大于99％。这些属性随着时间的推移而结合稳定性，从而提高了良好的跟踪效率。目前，以光束背景命中为主的占用率很低（在最内向的层中约为0.5％），这对SVD数据重建没有任何问题。鉴于未来几年预见的较高发光度的操作，旨在保留跟踪性能的特定策略已经开发并在数据上进行了测试。触发器的时间稳定性允许减少带状放大器波形的采样。可以利用良好的命中时间分辨率，以进一步提高较高的光束背景水平的鲁棒性。辐射损伤对条噪声，传感器电流和耗尽电压的最初影响已经测量：它们对检测器的性能没有任何不利影响。此外，由于光束损失而突然而强烈的辐射突然突然爆发后，未观察到SVD的损害。
Since the start of data taking in spring 2019 at the SuperKEKB collider (KEK, Japan) the Belle II Silicon Vertex Detector (SVD) has been operating reliably and with high efficiency, while providing high quality data: high signal-to-noise ratio, greater than 99% hit efficiency, and precise spatial resolution. These attributes, combined with stability over time, result in good tracking efficiency. Currently the occupancy, dominated by beam-background hits, is quite low (about 0.5% in the innermost layer), causing no problems to the SVD data reconstruction. In view of the operation at higher luminosity foreseen in the next years, specific strategies aiming to preserve the tracking performance have been developed and tested on data. The time stability of the trigger allows reducing sampling of the strip-amplifier waveform. The good hit-time resolution can be exploited to further improve the robustness against the higher level of beam background. First effects of radiation damage on strip noise, sensor currents and depletion voltage have been measured: they do not have any detrimental effect on the performance of the detector. Furthermore, no damage to the SVD is observed after sudden and intense bursts of radiation due to beam losses.
