About MC event data standard format and using SSD.jL for charge clouds

[Yangjzh0419]

Hello, thank you very much for developing such a user-friendly and convenient project, also thanks to your previous patient answers.
At present, I want to simulate the charge cloud of multiple events, but do not know how to achieve.

According to the tutorial, I use NBodyChargeCloud function to simulate a charge cloud for an event, like this:
center = CartesianPoint{T}([0,0,0]) energy = 1460u"keV" nbcc = NBodyChargeCloud(center, energy, 100) evt = Event(nbcc) simulate!(evt, sim, diffusion = true, self_repulsion = true)

According to the tutorial, I use this function to simulate waveforms for multiple events like this:

mc_events = open(read, mctruth_filename_csv, Geant4CSVInput)
mc_events_clustered = @time SolidStateDetectors.cluster_detector_hits(mc_events, 0.1u"mm")
hits = ungroup_by_evtno(mc_events_clustered)
mc_events_per_det = group_by_evtno_and_detno(hits)
mc_events_by_det = Table(consgroupedview(mc_events_per_det.detno, Tables.columns(mc_events_per_det)))
mc_events_det1 = Table(mc_events_by_det[1])
contact_charge_signals = simulate_waveforms(      
        mc_events_det1,
        sim,
        Δt = 4u"ns", 
        verbose = false,
        diffusion = false, 
        self_repulsion = false,
)

But I don't know how to simulate the waveform of charge cloud for multiple events like from MC data ?
Thanks and best wishes!

[fhagemann]

Thanks for the question.

Maybe first as a general remark: there should be documentation for all exported functions that you can access in the REPL using a question mark and then the function name. For example, to get more information about the MC data function simulate_waveforms, you can use

?simulate_waveforms

which gives

search: simulate_waveforms

  simulate_waveforms( mcevents::TypedTables.Table, sim::Simulation{T}; kwargs...)
  simulate_waveforms( mcevents::TypedTables.Table, sim::Simulation{T}, output_dir::AbstractString, output_base_name::AbstractString; kwargs...)

  Simulates the waveforms for all events defined in mcevents for a given
  Simulation by

    1. calculating the drift paths of all energy hits defined in
       mcevents,

    2. determining the signal (waveforms) for each Contact, for which a
       WeightingPotential is specified in sim.weighting_potentials.

  Arguments
  ===========

    •  mcevents::TypedTables.Table: Table with information about events
       in the simulated setup.

    •  sim::Simulation{T}: Simulation which defines the setup in which
       the charges in mcevents should drift.

  If HDF5.jl (https://github.com/JuliaIO/HDF5.jl) is loaded, this function has
  additional arguments.

  Additional Arguments (HDF5)
  =============================

    •  output_dir::AbstractString: Directory where the HDF5 output file
       is saved.

    •  output_base_name::AbstractString: Basename of the HDF5 output
       file, default is "generated_waveforms".

  Keywords
  ==========

    •  max_nsteps::Int = 1000: Maximum number of steps in the drift of
       each hit.

    •  Δt::RealQuantity = 4u"ns": Time step used for the drift.

    •  diffusion::Bool = false: Activate or deactive diffusion of charge
       carriers via random walk.

    •  self_repulsion::Bool = false: Activate or deactive self-repulsion
       of charge carriers of the same type.

    •  number_of_carriers::Int = 1: Number of charge carriers to be used
       in the N-Body simulation of an energy deposition.

    •  number_of_shells::Int = 1: Number of shells around the center
       point of the energy deposition.

    •  verbose = false: Activate or deactivate additional info output.

    •  chunk_n_physics_events::Int = 1000 (HDF5 only): Number of events
       that should be saved in a single HDF5 output file.

  Examples
  ==========

  simulate_waveforms(mcevents, sim, Δt = 1u"ns", verbose = false)
  # => returns the input table `mcevents` with an additional column `waveform` in which the generated waveforms are stored

  import HDF5
  simulate_waveforms(mcevents, sim, "output_dir", "my_basename", Δt = 1u"ns", verbose = false)
  # => simulates the charge drift and saves the output to "output_dir/my_basename_evts_xx.h5"

  │ Note
  │
  │  The drift paths are just calculated temporarily and not returned.

  │ Note
  │
  │  Using values with units for Δt requires the package Unitful.jl
  │  (https://github.com/PainterQubits/Unitful.jl).

You can see, that simulate_waveforms takes similar keyword arguments like NBodyChargeCloud.

If you want to simulate each charge cloud with 100 charges, you could do the following:

contact_charge_signals = simulate_waveforms(      
        mc_events_det1,
        sim,
        Δt = 4u"ns", 
        verbose = false,
        number_of_carriers = 100, # new
        diffusion = true, # new
        self_repulsion = true, # new
)

Is this what you were asking for or is the question how to save the MC data in the format that SolidStateDetectors.jl can interpret it correctly?
For the latter, I might refer to #272.

[Yangjzh0419]

Hello, according to your suggestion, I understand how to solve this problem.
Thank you for your suggestions, which are very helpful to me.

Thanks again for your help, best wishes!