Sensors designed for the CMS Preshower detector were irradiated with protons and neutrons to fluences equivalent up to 2×10{sup}14 n/cm{sup}2. The leakage current and the capacitance as well as the charge collection efficiency and the noise were measured, before and after the irradiation, for most of the detectors. We noticed, that for some detectors of a lower quality, the breakdown voltage increases after type inversion and that their leakage current, charge collection efficiency and noise are comparable to good detectors. We explain this phenomenon by two effects: a change of the distribution of the electric field and a decrease of the carriers lifetime. Defects on the p-side do much less harm after type inversion, because the maximum of the E-field is now on the n-side. Defects on the n-side still generate charge carriers, but their lifetime is much shorter and most of them recombine before reaching by diffusion the space charge volume. The article presents the measurements of the breakdown voltage, the charge collection efficiency and the noise before and after irradiation of such sensors compared with detectors of a high initial quality.
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机译：为CMS爆震检测器设计的传感器用质子和中子照射，以流速相当于2×10 {sup} 14 n / cm {sup} 2。对于大多数探测器，在照射之前和之后测量漏电流和电容以及电荷收集效率和噪声。我们注意到，对于一些质量较低的探测器，击穿电压在型反转后增加，并且它们的漏电流，充电效率和噪声与良好的探测器相当。我们通过两种影响解释了这种现象：电场分布的变化和载体寿命的减少。在类型反转后，P侧的缺陷会减少危害程度较小，因为E场的最大值现在在N侧。在N端上的缺陷仍然产生电荷载体，但在通过扩散到达空间电荷量之前，它们的寿命在达到之前重新组合。与高初始质量的探测器相比，该物品介绍了击穿电压，电荷收集效率和噪声之前和之后的噪声。
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