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v3.2.9
Intro:
- should we go back to Tuesdays? —> doodle
- start filling up a backgrounds table
Tony:
- threshold for number of photons to absorb for being above the effective rest mass increases (with xi). This is why the rate goes down with xi when chi is approaching 1.
- try to take the average xi in the MC shapes in slide1 instead of the max
- try to zoom in on the y-axis range where we have data points
- show what we call effective xi and maximum xi ?
- could this mass shift threshold mentioned in s1 (bullet 5) also decrease the rates? (Maryna sees decrease of the Compton rates at higher xi there’s). —> it shouldn’t! could be that there is a cutoff introduced by Tony (will check).
- should we have this plot or similar in the CDR?
- for this, do the OPPP with 9 GeV photons (due to the inverse Compton)
- then, will do this also for BPPP
Beate:
- huge impact going from xi max to xi avg
- need to normalise by the spot size (measure of the luminosity)
- need to recreate the points on the left with the new mesh to see if the step goes away. If the new mesh do not match with the points on the left then all the previous points should be re-done.
- still cannot understand the factor of ~O(1) between the JETI40 and phase2 (could be with Sasha’s “lumi code" it can go away)
- ICS beam also diverges like 1/gamma (similar to the Bremss).
- need the full photon spectrum, not only the ones which are on-axis
Sasha:
- running in the other cluster is promising
- reweight the HICS to Bremss to exploit the large stat we have with the Bremss.
- the beamdump setup is under study
- we need to generate as many beam-only BXs as possible and then merge these with the ones from Tony, while removing the bam-particles from his input files (with a simple E<16.5 GeV cut…) before plugging these in the G4 simulation. This will remove the duplications. The G4 simulation of the signal files from Tony without the beam component should be fast.
Maryna:
- please split the 2D plots to the 3 species (e+.e-,y)
- particles produced in air (taken as signal here) can be driven by the flux existing the dump.
- other backgrounds are also proportional to the photon flux which we want to measure as well besides the measurement of the Compton edges. So, if these measurements can be done, then we can stop optimising the bkg studies.
- GLS: can operate the setup without the magnet. HA: can also scan the B-field.
Kyle:
- from FLUKA, it is possible to see the 1st Compton edge, although this sim doesn’t include the e-beam dump - this is consistent with what Maryna was showing.
- Sasha: photon spectrum is known - it can be taken as a constraint for the method in slide 8?
- John: are you sure the e-loss is proportional to the energy? John says it is proportional to beta.