Editorial discussion of Physics and Detector CDR.
CDR Editors Email List: cepc-cdr-dp-editors@maillist.ihep.ac.cn
CEPC CDR meeting
Tuesday, July 17, 2018 from 14:00 to 17:20 (Asia/Shanghai)
at IHEP ( A623 )
Attending: Joao, Qun Ouyang, Zhijun Liang, Chengdong Fu, Yunpeng Lu, Xin Shi, Gang Li, Hongbo Zhu, Zhaoru Zhang, Franco G.(Vidyo), Jianming Qian (Vidyo), Yuanning Gao (Vidyo)
1. Progress of Full Silicon Tracker Option for CDR
Chengdong reported the status for full silicon tracker session. Here is the sum of the comments:
1) The full silicon tracker’s name is decided: FST1, FST2. They will update the name in new version.
2) Joao will help to add an introduction at the beginning of Chapter 4, to specify the baseline and other options.
3) Now full silicon tracker has two options, we need to point out the reason for having two layouts. The suggestion is to base it on the cost. One option has a lower cost at the expense of a small degradation of the performance.
4) The D0 resolution distribution of full simulation are not coincident between Weiming and Sergi's layout.
People analyzed the reason may be the package for two full simulation are different.
Chengdong will contact Weiming and Sergi to check the simulation, to understand the reason for the difference of the D0 resolution on full simulation. Otherwise we can just use fast simulation results, or only compare Weiming layout and TPC layout, since they are using same simulation.
Timescale for the plots: The figure will be re-drawed by Weiming in this week
5) Joao asked for an updated tracking system layout plot (Fig 4.6) to include the new MDI part, and a new plot to include the exterior layers of the tracker outside the TPC. Gang will find out who made the current plot (maybe Hongbo) and update a new one. Joao suggested one could also extract the plot from the Geant geometry.
2. Drift Chamber status from Franco
1) Joao suggested Franco to check the track requirement parts in the introduction in Chapter3. Franco should suggest modifications to that chapter and make sure the information that he needs is included.
2) Joao suggested Franco to prepare the basic information of drift chamber readout and DAQ requirement for chapter 8 DAQ. Franco will put the information in chapter 4.5 and people will summarize it in chapter 8.
3) There was some discussion on how to harmonize the descriptions of the IDEA detector for both FCC-ee and CEPC CDR's. Currently the text says the detector was explicitly designed for the CEPC. This statement might be awkward if it is reversed in the FCC-ee CDR, Joao suggested they statements in both CDR's should be in sync, and it might be better just to say that detector was optimized for a circular ep collider.
4) Franco will try to get a new version by end of this week
3. Go through the Charlie’s comments for Vertex chapter
Most of text referring with ILD or ILC will be removed or modified. We try to justify decisions based on our own studies.
1) Spatial resolution near the IP better than 3um; —> 3um point to the single point resolution
2) First layer located at as close to beam pipe as possible —> quantify “close to beam pipe”: add the information for the material budget of beam pipe with 0.15%, and radius is 14mm (need to be checked by Chengdong)
3) Chengdong will make a material budget plot for baseline (from beam pipe to TPC)
4) Don't mention power-pulsing mode, remove this sentence “Unlike like the ILD vertex detector, which operates in power-pulsing mode, the CEPC detector must operate in continuous mode. ”
5) In Table 4.1, check the reason for the Layer2 readout time with 1-10 ns. Make sure the number is reasonable.
6) For Figure 4.3, check the reason for the full simulation being BETTER than fast simulation at 20 degree with 1GeV. This should be due to a mistake somewhere. If cannot be understood, it is better to rely on the fast simulation.
7) For Table 4.3, why can STAR use air cooling with much more power dissipation, at 170 mW/cm^2 than we plan to have50 mW/cm^2? Zhijun says he read a paper that explains that the level of air flow in the STAR experiment causes vibrations that affect the detector resolution. They are trading resolution for cooling but they don't need as good resolution as we do. Ouyang will check the details in the paper.
8) Mention the pixel “prototype” from MOST 2 in the end of this section. Joao or Zhijun will add a sentence.
Ouyang will discuss these questions with his student and rewrite this session in this week. The difficulty is the question for readout time.
Joao mentioned to Ouyang how to modify the plots in this session, some of the plots will only include the fast simulation’s results. One plot will show there is little difference between the two simulations. After the new version coming out, we will send it to Charlie and other general editor for more comments. Yuanning will also help to review it.
TPC and Silicon trackers will be discussed in tomorrow’s meeting