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

Garfield++
1

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.

2

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.

3

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

4

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

5

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

image
image1642×827 110 KB

I still can’t get the result

6

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";
7

Hi,
Thanks a lot for your reply and kindly help.
I have got the results like this:
image
But the other plot shows the collecting time is nearly about 450ns to the balance

image
image1560×787 10.2 KB

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

8

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

9

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

10

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?