Add RMC as a muon stop pileup product option #1375
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Hi @michaelmackenzie,
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☀️ The build tests passed at e944805.
N.B. These results were obtained from a build of this Pull Request at e944805 after being merged into the base branch at f5aa30e. For more information, please check the job page here. |
| @@ -125,6 +125,7 @@ double physicsParams.Al.capture.protonRate = 0.05; | |||
| double physicsParams.Al.capture.deuteronRate = 0.025; | |||
| double physicsParams.Al.capture.neutronRate = 1.2; | |||
| double physicsParams.Al.capture.photonRate = 2.0; | |||
| double physicsParams.Al.capture.RMCRate = 9.460e-5; | |||
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Is there provenance for this number? Does it implicitly assume a cutoff energy? Can that be documente?
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This is from the TRIUMF measurement of 1.4e-5 for E > 57 MeV, divided by the closure fraction above 57 MeV. Should I add this as a comment here or document it somewhere else?
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Please add it as a comment after this line. We need to document the provenance of every physics number in this table, which is beyond the scope of this PR. I will open an issue once the PR is merged
| @@ -45,14 +45,16 @@ namespace mu2e { | |||
| _czmin(conf().spectrum.get<fhicl::ParameterSet>().get<double>("czmin", -1.)), | |||
| _czmax(conf().spectrum.get<fhicl::ParameterSet>().get<double>("czmax", 1.)), | |||
| _spectrum(BinnedSpectrum(conf().spectrum.get<fhicl::ParameterSet>())), | |||
| _useRate(conf().spectrum.get<fhicl::ParameterSet>().get<bool>("useRate", false)), | |||
| _internalRate((_external) ? 0. : 1.), | |||
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I’m struggling to follow the settings needed to get the following configurations
- external (photons) only
- internal conversions only
- physical admixture of internal and external
Some combination of the ‘external’ and ‘userate’ bools seems to provide these, but I can’t quite follow.
It would be clearer if the valid configuration options were explicitly enumerated (enum) and set in the config.
I also find the term ‘external’ for producing RMC photons unintuitive, as those photons might be detected directly in the calorimeter, in which case there’s nothing ‘external’ about them.
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Only one of the external or useRate flags are necessary. I updated the configuration to use validated fhicl and in the update I set the external flag to only be required if useRate is false. I could update this to use strings or enums to check for something like "natural", "external", or "internal" if this is a preferred logic. I also don't prefer external as I term (I typically write real photons or virtual photons/internal conversions in talks), but it better matches the process IDs used and alternate generators.
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I prefer the conceptually more clear config to choose between the 3 sensible options. The names you give above are clear. If the process names are unclear we can change them, but lets do that in a separate PR.
Add logic for RMC to be included as a muon stop pileup product. This mostly entailed adding a flag to the RMC tool to use the RMC rate per muon to generate a random number of photons (usually 0), and add the corresponding global constant. The global constant RMC rate for aluminum is 1.4e-5 for E > 57 MeV over the closure approximation spectrum fraction for E > 57 MeV (~1/10,000 muon captures). I will make a corresponding PR in Production adding this product to the MuStopPileup configuration.