How to get the time of the electrons drifting to collecting plate

[XiCheng]

I want to calculate the time of the electrons drifting to the collecting plate when proton passing through the gas ionization chamber, which function I should use and how to confirm the coordinates of the collecting plate because the model is imported from the ansys.

[hschindl]

It depends on the class that you are using for simulating the electron drift.
With AvalancheMicroscopic and AvalancheMC you can do something like this:

for (const auto& electron : aval.GetElectrons()) {
  const auto& endPoint = electron.path.back();
  const double driftTime = endPoint.t;
}

See also Examples/Gem/gem.C · master · garfield / garfieldpp · GitLab

With DriftLineRKF you can use the function GetDriftTime.

[XiCheng]

Hi,
Thanks for your help. I have used the DriftLineRKF in my code, so I choose to use the GetDriftTime, however there must be something wrong like the code used below

 DriftLineRKF drift;
  drift.SetSensor(&sensor);
  drift.SetMaximumStepSize(0.01);
  drift.GetDriftTime();

I can’t get the result of the drifttime

[hschindl]

You first need to simulate a drift line (drift.DriftElectron(...)).

[XiCheng]

Thanks for your help
I add the code like thisDriftLineRKF drift; drift.SetSensor(&sensor); drift.SetMaximumStepSize(0.01); drift.DriftElectron(-11.7, 20.42, -7.53, 0.); drift.GetDriftTime();
and the result is like this

I still can’t get the result

[hschindl]

GetDriftTime returns a double; if you want to print out the drift time you need to do something like

std::cout <<  "Drift  time: " << drift.GetDriftTime(); << " ns\n";

[XiCheng]

Hi,
Thanks a lot for your reply and kindly help.
I have got the results like this:

But the other plot shows the collecting time is nearly about 450ns to the balance

So would you please explain the different results for me ? Thanks a lot.

[hschindl]

What exactly does the plot show? The signal from a single electron? Or from all electrons on a charged-particle track?

[XiCheng]

it’s the IntegrateSignals, looks like all lectrons on a charged-particle track and then normalized.

[hschindl]

Ok. So to what starting point does the drift time (239 ns) correspond to? If it’s for an electron that has to drift all the way through the chamber then I would indeed expect it to be identical to the duration of the signal; but maybe it’s an electron released somewhere in the middle of the gap?