To Simulate charged-particle tracks using Heed, after avalanche of the ionized electrons will be simulated in single layer GEM detector, but i getting error

Garfield++
1

Create the TrackHeed object for primary ionization
track = ROOT.Garfield.TrackHeed()
track.SetParticle(‘muon’) # Define the particle type (muon)
track.SetEnergy(180.e9) # Set particle energy (180 GeV for muon)
track.SetSensor(sensor)
track.Initialise(gas, True)# Attach the sensor to TrackHeed
track.EnableElectricField()

aval = ROOT.Garfield.AvalancheMicroscopic()
aval.SetSensor(sensor)
#aval.SetCollisionSteps(100)

zi = 0.5 * lem_th + lem_cpth + 0.1 # Starting z position
ri = (lem_pitch / 2) * np.random.uniform() # Random radius within the LEM pitch
thetai = np.random.uniform() * 2 * np.pi # Random angle
xi = ri * np.cos(thetai)
yi = ri * np.sin(thetai)

Launch the charged particle through Heed.

track.NewTrack(xi, yi, zi, 0., 0., 0., 0.)

Retrieve the clusters of ionization produced by Heed

clusters = track.GetClusters()
print(“Number of ionization clusters:”, len(clusters))

Iterate over each cluster

for cluster in clusters:
# Instead of getting number of electrons, directly process the cluster
n_electrons = cluster.GetElectrons() # Assuming this method exists to get electron details
if n_electrons is not None:
print(f"Cluster contains {len(n_electrons)} electrons.")

    # Loop over each electron in this cluster
    for electron in n_electrons:
        # Retrieve the position of the electron
        x_e, y_e, z_e, t_e = electron.GetPositionX(), electron.GetPositionY(), electron.GetPositionZ(), electron.GetTime()
        
        # Optionally, you can print the position and time of the electron
        print(f"Electron: Position: ({x_e}, {y_e}, {z_e}), Time: {t_e}")
        
        # Simulate the avalanche for each electron
        aval.AvalancheElectron(x_e, y_e, z_e, t_e, 0., 0., 0., 0.)

print(“… avalanche complete with”, aval.GetNumberOfElectronEndpoints(), “electron tracks.\n”) when i running this code i’m encountering with error

AttributeError Traceback (most recent call last)
Cell In[22], line 4
1 # Iterate over each cluster
2 for cluster in clusters:
3 # Instead of getting number of electrons, directly process the cluster
----> 4 n_electrons = cluster.GetElectrons() # Assuming this method exists to get electron details
5 if n_electrons is not None:
6 print(f"Cluster contains {len(n_electrons)} electrons.")

AttributeError: ‘Cluster’ object has no attribute ‘GetElectrons’

please someone help me my code is correct or incorrect? give some suggestions. I’m totally beginner in Garfield++

2

Hi,
as you can see from the error message by the interpreter, a Cluster object does not have a function GetElectrons. To loop over the electrons in a cluster you can do something like this:

for cluster in clusters:
  for electron in cluster.electrons:
    # ...

As suggested in the other thread, please have a look at one of the examples:

3

Dear @Dk_ntm

We are very happy you are new to garfield and you find the software valuable to perform your research. We are als happy on the forum to provide help, guidance and discussion. Could you please write clearly what exactly you want to do, and what problem you encounter / what concept you do not understand? You can put snippets of code in your message, or even attach a file with code, but please do not throw in code like this, we are not AI that scans through your code and highlight mistakes and search for the questions or your intentions.

This said, if you are new to garfield, you are very well invited to have a look at the documentation, especially take your time (just one evening) to read through the manual, that is pretty well written, and use the doxygen that shows you which are the methods available in each class and what they return. Third, please have a look at the examples.

In your specific case I would believe this is way to optimistic programming and is a recipe for running into troubles:

as you can se here cluster is a struct and you can access its vector of electrons through cluster.electrons. This you could have found out going through this example

Kind regards
Piet