Effects of accelerated annealing on p-type silicon micro-strip detectors after very high doses of proton irradiation
Effects of accelerated annealing on p-type silicon micro-strip detectors after very high doses of proton irradiation
复制标题
高剂量质子辐照后加速退火对 p 型硅微带探测器的影响
DOI：
10.1016/j.nima.2006.05.200
复制
发表时间：
2006
影响因子：
1.4
通讯作者：
A. Watson
中科院分区：
文献类型：
--
作者：
G. Casse;P. Allport;A. Watson
在p型衬底上生产了具有n侧读出的微型（1cm长度）条形探测器，以利用暴露于强子的大通量后从n侧读出分段器件的优点。在升级后的大型强子对撞机（sLHC）上，用24GeV/c的质子对这些p型原型进行了三次辐照，辐照剂量分别为1.1、3.5和7.5×1015cm−2，与内跟踪器的预期剂量（不同半径）相匹配。我们之前已经证明，即使在最高剂量后，这些设备的信号噪声比也大于8:1。在反向退火开始之前，在辐照后完全耗尽电压退火曲线的最小值处进行测量。我们现在研究了在80°C加速退火后的电荷收集性能。在此温度下，退火的效果比室温加快了约7400倍，并且我们的研究跨越了在室温下等效退火数年的时间。就电荷收集效率而言，结果与用电容电压技术测量的完全耗尽电压的演变形成鲜明对比，并表明这些强辐照检测器可以在室温下长时间保持而不会降低其性能（例如，在维护期间）。同样明显的是，用它们的完全耗尽电压来描述这些强辐照器件已不再适合于预测它们的电荷收集特性。
Miniature (1cm length) strip detectors have been produced with n-side read-out on p-type substrates to exploit the advantages, after exposure to large fluxes of hadrons, of reading out segmented devices from the n-side. These p-type prototypes have been irradiated with 24GeV/c protons to three fluences compatible with the expected doses (at different radii) for the inner tracker at the upgraded LHC (sLHC), namely 1.1, 3.5 and 7.5×1015cm−2. We have previously shown that those devices exhibit a signal to noise greater than 8:1 with LHC speed electronics even after the highest dose. The measurements were performed at the minimum of the curve of the annealing of the full depletion voltage after irradiation before the reverse annealing sets in. We have now studied the charge collection performance after accelerated annealing at 80°C. At this temperature, the effects of the annealing are accelerated by a factor of about 7400 compared to room temperature, and our study spans an equivalent annealing time of several years at room temperature. The results, in terms of charge collection efficiency, are in sharp contrast with the evolution of the full depletion voltage as measured with the capacitance-voltage technique and suggest that these heavily irradiated detectors can be kept at room temperature for long periods without degrading their performance (e.g., during maintenance time). It is also apparent that the description of these heavily irradiated devices in terms of their full depletion voltage is no longer appropriate for the prediction of their charge collection properties.