The program probably gets killed because the avalanche becomes very large. You could set a limit to the avalanche size by adding a line like fAvalanche->EnableAvalancheSizeLimit(10000); (which will cut the avalanche growth at 10 000 electrons), as I suggested in earlier reply.
In general, I don’t think the gas mixture you are using is particularly suitable for a wire geometry, as I tried to say before.
thanks dear i’ll see that to.
also how to calculate the Bethe-born cross-section?
Not sure I understand the context of the question. It doesn’t have to do anything with the discussion in this thread so far, does it?
The Bethe-Born formula for the ionisation cross-section is
where
The parameters lnc and M2 are given by the dipole oscillator strength density.
For more details see
dear i have entered the line here is it correct? but it still killed the process after some hundred events.
Yes, that’s the right place. Not sure why your program gets killed. It could be that there is a memory leak, I’d have to look into it (I’ve only run this example for a few events so far).
As a workaround/simple solution, can you perhaps just simulate 100 events at a time?
ok dear.
i have ran it again for 200 events all gone well but gain avalanch size is still zero. and in the graphs in the root files showing 200 entries in the legends but nothing is in front.
have you checked why it is contineously killing the simulation?
Aren’t there two different issues?
For low voltages on the wire, you get zero gain. I don’t think this is a bug in the program but a consequence of the fact that the electron has to cross a region with low electric field before it reaches the wire. At low field, you have significant attachment so there is a high probability that the electron is lost before it has a chance to start an avalanche. As I’ve tried to tell you before, that’s why I’m not sure if the gas mixture you are using is suitable for a wire geometry.
If you set a too high voltage on the wire, then the gas gain becomes very large (at least for the electrons that actually reach the wire) and the simulation will take a long time because AvalancheMicroscopic follows every single electron trajectory in the avalanche. If you are not interested in gas gain fluctuations, you could use DriftLineRKF instead of AvalancheMicroscopic which simply integrates the Townsend and attachment coefficients along the average drift path.
ok dear i’ll check that too.
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