RestG4 ion simulation: step size cannot be modified

RestG4
1

System : Linux,
REST version : v2.2.10
Hi:

electron_track
electron_track809×780 6.35 KB
F19_track
F19_track732×383 1.37 KB

We want to simulate a F19- ion going through low-pressure CF4 gas with restG4, but the step seems too large. For instance, I attached a picture including a 25kev original track(the white line), but there are only 8 hits. Then I decrease the MaxStepSize and cut parameters in the restG4 config file(F19-.rml), which doesn’t change the simulation results. At the same time, the simulation of an electron track will effect by changing such parameters.
Thanks a lot!

2

Hi Bofang, thanks for reporting this.

In which geometry volume those hits are taking place? Could you share your GDML file?

Actually maxTargetStepSize will only affect the sensitive volume (usually the detector active medium). However, right now it is hard-coded inside DetectorConstruction to be using the volume named gasVolume (see image later on). We probably need to change that, but I want to check the source of your problem is coming from there.

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371758×650 260 KB

3

Setup_WIMP_CuVessel.gdml.rml (19.1 KB)
materials.xml.rml (11.8 KB)
Setup_WIMP_CuVessel.gdml.rml (19.1 KB)
Hi javier,

Thanks for your reply. Please find attached my gdml files. Since gdml is not authorized name, I added .rml on the end. Here I used PandaX-III Cu vessel geometry, with CF4 mixture gas inside.
So does it means that the mistake may come from the gas itself? Because the electron performance seems correct while the ion track is strange.

4

Ok, now gdml is also authorised. The geometry file where you define the volumes seems missing.

What is the typical distance between 2 hits? Could you also attach the result from PrintEvent for electron and ion? I believe the ion track is much much shorter than the electron and that’s why visually seems strange?

5

Ok, there is somewhere else where the particles that are affected by this is taken into account. Inside restG4/src/PhysicsList.cc

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42792×437 56.4 KB

It seems only electrons and muons are considered for limiting the integration step.

I have added a patch at branch v2.2.11_dev, adding the following lines to PhysicsList.

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081049×156 25 KB

Could you update your local copy to branch v2.2.11_dev, and check the results with the ion?

6

Thanks for your information. Sorry, I’ve no idea on how to update Rest from master branch to v2.2.11_dev, but I updated restG4/src/PhysicsList.cc to your newest version.

It seems there’s still some problem when simulating ion movement. I attach the log as follows. I guess it’s an error defined by G4SetppingManager.cc but I use /store/bl2/opt/geant4/10.02p01/ which has no source files. Could you please point me out where’s the error probably from?

error_steppingmanager
error_steppingmanager1815×1044 41.6 KB

Thanks again!
Bofang

7

Hi Bofang,

It is important that we work on the same version of the code, so that I could reproduce your error. I will not be able to help you if you don’t change to v2.2.11_dev.

if you are in the master branch, you may proceed in two different ways.

Option 1. If you do not mind to discard the changes you have locally.

git reset --hard
git fetch
git checkout v2.2.11_dev

Option 2. You want to save your local changes.

git stash
git fetch
git checkout v2.2.11_dev

You should be in a clean v2.2.11_dev branch, check that having a look to the output of git status.

You may recover back later on using git stash pop, but make sure you test the problem with a clean version of the code, without local modifications.

8

Hi Javier,
Thanks for your advice, I’ve switched to v2.2.11_dev branch. However, the error was the same. I attach the screenshot as follows.

error_steppingmanager
error_steppingmanager1960×949 38.4 KB

Thanks for your help!
Bofang

9

Could you provide also your RML containing TRestG4Metadata, TRestPhysicsList, etc definitions, and all the geometry files you used so that I can reproduce the error?

10

F19-.rml (3.7 KB)
materials.xml.rml (11.8 KB)
Setup_WIMP_CuVessel.gdml.rml (19.1 KB)

Hi Javier,

I attached these files. Thanks for your help!

Bofang

11

a.txt (52.2 KB)

image
image1226×220 12.4 KB

Sorry, I missed one file, “Geometry_CuVessel.gdml”. By the way, it took me some times to upload it successfully, it seems there’s some bug like that in the image

12

I didn’t have time yet to look at this. I have created an issue to track this problem.

13

Hi Javier,
Sorry I cannot log in the website you mentioned, which needs an account of unizar…

14

Hi Bofang, you just need to create an account, registration is open to everyone.