Warning: Internal error for charge starting xxx

[zql2021]

Hello Felix,

I recently encountered a warning while simulating gap events for a double-sided strip HPGe detector. Below is my code :

T = Float32  
position = (0.0, 1.5, 2.8)  # mm  
pos = CartesianPoint{T}(position[1]/1000.0, position[2]/1000.0, position[3]/1000.0)  # convert mm to m  
Edep = T(100) * u"keV"  
nbcc = NBodyChargeCloud(pos, Edep, 50, number_of_shells=2)  
evt = Event(nbcc)  
simulate!(evt, sim, max_nsteps=10000, Δt=0.1u"ns", diffusion=true, self_repulsion=true, verbose=true)  

The initial position (0.0, 1.5, 2.8) means the center of the gap for the top strip contact

The warning message is:
Warning: Internal error for charge starting Float32[-1.3050303f-6, 0.0014977396, 0.0028097408]

println("cd_point_type = ", cd_point_type) returns cd_point_type = 1, indicating CD_OUTSIDE. However, even consider charge cloud expansion, the position should not be outside the detector.

I suspected a floating-point precision issue (e.g., Float32 limitations). Switching to T = Float64 caused a method error:

ERROR: MethodError: no method matching simulate!(::Event{…}, ::Simulation{…}; max_nsteps=10000, Δt=0.1u"ns", diffusion=true, self_repulsion=true, verbose=true)  
Closest candidates:  
  simulate!(::Event{T}, ::Simulation{T}; max_nsteps, Δt, diffusion, self_repulsion, verbose) where T<:Union{Float16, Float32, Float64}

Could you give me some advice for this issue? Looking forward to your insights.

[fhagemann]

Both, the Simulation and the Event would need to be in Float64.
The error you see results if e.g. the Event is Float64, but the Simulation is still Float32.

[zql2021]

I see, I will set both the simulation and event Float64.
Thank you so much!