Weighting Potential Reader module

Issues
1

Dear Developers,

I installed the latest version of Allpix2 using the Docker file with this FROM:
FROM gitlab-registry.cern.ch/allpix-squared/allpix-squared/allpix-squared-deps:v2

Since some parameters have been changed wrt the old Allpix2 version that I was using (v. 1.6), I want to make sure that I obtain consistent results if I use exactly the same EF / WP maps extracted from TCAD.
I encountered a problem with the Weighting Potential Reader module, since this was the weighting potential map that I obtained with the old version (it’s a .init file computed for a 3x3 sub-matrix)

WP
WP961×843 8.19 KB

With the new Allpix2 version, I had to add the field_mapping parameter, for both the electric field and the weighting potential module. I already checked that the electric field plotted in the ElectricFieldReader module is consistent, but for the WP I obtained this strange plot:

wp_new
wp_new1015×843 9.96 KB

I would like to use a 3x3 weighting potential map and I’m using the field_mapping = SENSOR.

Could you help me to understand the problem?

Thanks a lot,
Chiara

2

Ciao @cferrero

could you post the full configuration section of the WeightingPotentialReader module by any chance? Thanks!

/Simon

3

…and one more idea: Does it work if you set the field_mapping = PIXEL_FULL?
You have an electrode-centered 3x3 matrix, so always starting from the pixel center should work…

4

Dear @simonspa,

thanks for your reply. This was my configuration for the module:

[WeightingPotentialReader]
model = “mesh”
field_mapping=“SENSOR”
file_name = “Name_file.init”
output_plots = true

but now I moved to “PIXEL_FULL” and it seems working well :slightly_smiling_face:

wp_new_PIXEL_FULL
wp_new_PIXEL_FULL959×843 9.1 KB

The only point that I don’t understand is the potenzial_z plot, which looks like this:

wp_new_PIXEL_FULL_potentialz
wp_new_PIXEL_FULL_potentialz959×843 9.25 KB

I don’t know which z-coordinate this plot is referring to, I saw the parameter
output_plots_position: which is the 2D Position in x and y, but I don’t see a parameter to fix the z coordinate for the plotting.

Thanks,
Chiara

5

Hi @cferrero

thanks for reporting back, indeed the SENSOR version should not even be possible for the weighting potential… I fixed this in WeightingPotentialReader: Exclude SENSOR mapping (!882) · Merge requests · Allpix Squared / Allpix Squared · GitLab

Also there, I added a new parameter (and updated the docuemntation to clarify) for your second issue - right now, the value is always taken at z = 0. so in the center of the sensor. Which admittedly doesn’t make a lot of sense in many cases. With the new parameter you can chose the depth (between +d/2 and -d/2 where d is the thickness).

Cheers,
Simon

6

Thanks a lot Simon for your support,

Cheers,
Chiara