https://indico.ihep.ac.cn//event/8183/

First,Yuzhen can’t join this meeting, we scaned Ultra-fast silicon detectors briefly. Next, we saw other’s questions and she answer.

Suyu: How can we get the characteristic trapping time if we know a trapping length? Answer: For my understanding, trapping length is relative to the thickness. Trapping time is the collection time, it is the test result. Or using the charge particle dynamics in electric field..

Amit: I just want to know a better explanation for figure 9A.I have searched about the Weightfield2, which is a software for 2D simulation for silicon detector. But I want to know about BD3 big 35pF, SD2 small 2.6pF,WF2_big and WF2_small and how they show the gain of 3.5 with the alpha particle injection? Answer: For my understanding, adjust the bias voltage to change the gain.

Kai: Since present experience with LGAD is limited to sensors with 300 μm thickness[4], a reliable tool is needed to extrapolate their performance to the planned thickness of 50 μm. why the thickness is so important? Answer: Thickness affects the running time of the electron and hole, thus effect the charge collected time and shape of LGAD pulse. There are concerned to the time resolution.

Ryuta: Broad-Band amplifier (BB) is emphasized many times throughout this paper, but what is the BB ? (actually, it remind me the other amplifier, CSA, though I’m not quite sure for both) Answer: Broad band amplifiers are amplifiers which will reproduce a wide range of signals without significant loss throughout the pass band. (I am also not so clear about BB) CSA is charge sensitive amplifier, the output is proportionate to the input charge.

Xin: Could you elaborate the two proposed reasons for the gain degradation in LGAD devices? Answer: In actual, don’t know. Sorry.

Yuhang: There are several analysis algorithms to optimize the time resolution. what’s extrapolation of the slope to the base line and constant fraction discriminator(CFD), in fig.6 the meaning of CFD%. Answer: Some picture to explain the question.

Finally,Yuhang introduced Frequentist statistics briefly in special topic.