R&D Studies of 3-dimentional particle tracking detector using CCD device for the particle physics

在未来的TeV对撞机上，短寿命粒子的顶点检测对于物理分析是至关重要的。利用高能束线上的最小电离粒子(MIP‘s)研究了一种基于最小电离粒子(MIP)的CCD跟踪器的性能。在信噪比高达+5ﾟC的情况下，我们成功地探测到了MIP。位置分辨率为3微米，比SLD实验中的4.7µm更好。我们还用强的β源考察了辐射损伤的影响。观察到电荷转移效率(CTI)的退化。为了研究CTI在不同参数下的行为，我们开发了一个复杂的模拟代码，可以很好地再现辐照后的数据。经过仔细检查，我们发现，即使在室温下(^-0ﾟC)，也可以通过修改时钟方案来提高抗辐射能力。此外，我们还成功地用15 OﾟC退火法消除了其中一个陷阱能级。这些研究的结果对于未来对撞机实验中辐射环境下的实际应用来说是令人鼓舞的。

Vertex detection of short lived particles in future TeV colliders plays essential roles for the physics analyses. CCD device is one of the most promising candidates since tracks can be reconstructed 3-dimensionally.We have studied the performance of a CCD tracker using minimum ionizing particles (MIP's) from a high energy beam line. MIP's are successfully detected with sufficient signal to noise ratio even up to +5ﾟC.The position resolution is found to be 3 mu m which is better than that in the SLD experiment, 4.7 mu m.We also have examined the effect of the radiation damage using a strong beta -source. The degradation of the charge transfer inefficiency (CTI) is observed. It is, however, found to be possible to recover it partially by increasing the drive pulse voltages.In order to investigate the behavior of the CTI against various parameters, we have developed a sophisticated simulation code, which reproduces the data taken after the irradiation reasonably well. After careful examination using this code, we have found that it is possible to improve the radiation tolerance even at the room temperature (^-0ﾟC) by modifying the clocking scheme.We have furthermore succeeded in eliminating one of the trap levels by annealing with l5OﾟC.The results we have obtained from these studies are encouraging in terms of the real application of CCD device under the radiation environment which is expected in the future collider experiments.