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v3.2.9
In general:
- fix fwd spect design (incl. the profiler - see below) by next week and implement in G4
- in 2 weeks: launch the 2nd iteration of the G4 bkg production with all the changes and after some preliminary analysis
- Matthew and Sasha will coordinate directly about the plots for the simulation section (before the detectors)
Tony:
- some precision-related bugs fixed (all seems good now, also checked by Arka)
- need to add the 3x3 um2 (and possibly 5x5 um2) spot-size for phase-1
- add a line in the table for the \xi values for phase1 case
Sasha:
- 3xBCs done so far in DESY cluster, a lot was also produced on the grid by Louis and about ~100M were produced at WIS
- slides 2-3-4 are very helpful for fastsim —> exactly the point of the seeding before the clusters are given to the KF alg
- please add plots like in slide 7 but vs y for the area around the setups
- Noam will send a link to the KF alg and selection etc. —> https://indico.desy.de/indico/event/26057/
- Aluminium cage can serve as the shield for the backscattering (probably ~1 radiation length is enough) —> TBC.
- how do we centralise the data?
- can copy things to DESY, practically only Arka doesn’t have access but we can do it via e.g. EOS
- in parallel, Arka should get access to DESY (tbc with Sasha)
Kyle:
- do we know what is the apparatus of the C-shape magnet?
- need to add its parameters in the parameter book
- Louis will share that and the B-field map
- lyso rad-hardness: can be greater than 10^4 Gy —> at least 115 days of operation - is this enough?
- fix x-axis label to “x [cm]” in the crystals response plots
- weird hotspots in the crystals response plots —> need to clarify where these come from.
- FLUKA for full setup simulations, since it is just Kyle who does that so far,
- the 1st priority is the finalisation of the fwd spectrometer design for the next G4 iteration.
- then we can move on to the full setup simulation with FLUKA
- the first step to do is to understand the resources needed (CPU, time, space, etc.) and how we distributing them.
- what about the profiler?
- Gianluca is looking into different options (maybe with INFN people who are interested to work on that)
- flux is huge, so solution would be scintillation-based: cesium+iodide —> TBC.
- need to discuss with Maryna if this can be placed after the shields (potential interference with the backscattering calo?)
- if not, it should be before the shielding
- either way it has to go in the next G4 model for bkg studies at least as a passive material in face of the beam
- Cherenkov in the fwd system:
- current G4 model assumes 15 cm lysos so not 100% acceptance and therefore there are Cherenkov detector placed to extend this acceptance.
- with the lyso being rad-hard enough, we will increase the length to 30 cm (~full acceptance) and remove the Cherenkov detectors. If we want redundancy we can always put these back but for the CDR it can just be mentioned while the bkg generation will be done without these.
Louis:
- can reach 25 um (cubic) precision from the XFEL survey system
- we need to know the IP position (can be <20 um) also considering pulse instabilities etc. For now we assume this is a given but the chamber will have to have some target mounted for the surveying.
- Everyone: estimate if 25 um (cubic) is both feasible and small enough. For that need to shift the detectors by ~25 um in each direction and see how the energy spectrum shifts.
- need to discus the B-field needs (Louis suspects we won’t be able to use the ones we’ve been counting on so far)
Matthew:
- can have B-field simulation but, if we buy a new one we can have it from the manufacturer.
- add the laser intensity uncertainties (~1% per-shot from Matt?) and the beam-laser alignment uncertainties (from Tony’s simulation)
- will coordinate with Sasha about the plots.