Solid EC To Do
From Hall A Wiki
SoLID EC To Do List
- What is causing pion rejection to level out at p>4GeV? (JP)
- If it's hard to explain we should change the cuts and make the plots more understandable.
- Ed is asking what algorithm we used for PID. We know it's based on two simple cuts, but can it be better?
- For radiaton dose plot, make sure people understand the points are "from photon entering the EC", not "photon" (since photons themselves don't do much damage). (Everyone)
- Also, for radiation plot, I copied from earlier slides a yellow box/arrow "Low E photon dominant". Why is low E photon dominant while the curves clearly show electrons are higher than photons?
- Answer from Zhiwen: THe electron include both DIS electron and background low E electron. We should separate the two and see what we get.
- Note from Jin: Zhiwen should include more realistic target material (glass, collimator, etc), and use refined physics list;
- If we can only reach 50:1 pion rejection we should work with other talks and make the physics requirement on PID more consistent. (Everyone)
- Zein-Eddine's Cherenkov talk indicates 100:1. Eric claims overall we can get <1% contamination using the latest EC rejection from Jin and pi/e from Seamus ()
- Winstone cones don't help much (Ed). They work for parallel light and fibers have ~26 degrees outgoing light angles;
- Zhiwen: addtional note, single clad fiber have about 26 degree light angle, double clad has more like 30 - 35 degree. So how good winestone cone is a question. I don't think we overlook it, it's just we need more information or even test about it. Hope Paul can help us and get some feedback from FNAL.
- Jin: We should not give up Winstone cone. Losing some light might be just okay.
- Ed: Bending preshower fiber and let them go back for readout may suffer from too much light loss. another way to readout preshower could be use some thin scintillator pad painted with WLS material and has clear fiber embedded in it. He said Russia had use something like that before, I will ask him more info.
- Clear fibers are difficult and will be a lot of work. Can we run silicon-based sensors or APDs just next to the module? With neutron shielding? (Ed)
- On top of that, can we use the same for forward angle ECs?
- Zhiwen: think if no cost issue, we should use same readout for both to simply the situation. but have to think about if we want the advantage of having readout stick outside of yoke and easy access for service.
- Price quote must be exact: Must have quote fro IHEP for the current (segmented) design, and the latest quote on the fibers. Same for clear fiber cost. Do not say "using $1.5 instead of $1.15 for safety". Contingencies should be estimated and added separated.
- Can we make the modules in China? (Ed) - No, China is more interested in funding their own projects. They funded GEM because it's a new technology that they can learn from CERN (Haiyan).
- My own question (or D. Mack's): When we say the light loss of the Kuraray fiber is 13% at 0.1Mrad, is that 13% per meter or independent of the fiber length?