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Defining and separating a medium around the model to be studied

Posted Jul 20, 2023, 7:59 a.m. EDT Electromagnetics, Geometry, Materials Version 6.0 4 Replies

Hershini Gadaria
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I am modeling a semiconductor detector which is supposed to be immersed in a Liquid Argon medium. I want to study how the electric fields change when the detector is in vacuum vs in the medium. However, I don't see any changes in the results when i swap out vacuum for argon. I also tested the scenario with copper (conductor) and quartz(insulator). I still did not see any changes in the fields. Any blogs I read, say that the second material (in this case, semiconductor) overwrites the medium around it. But I don't think this is happening. How do I fix this issue?

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4 Replies Last Post Jul 22, 2023, 1:57 p.m. EDT
Dave Greve Certified Consultant
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Posted: 9 months ago Jul 20, 2023, 1:02 p.m. EDT
Updated: 9 months ago Jul 20, 2023, 1:02 p.m. EDT
  1. You can see which domains are assigned to a material by clicking on the material name.
  2. Is the relative permittivity of liquid argon different from one??
1. You can see which domains are assigned to a material by clicking on the material name. 2. Is the relative permittivity of liquid argon different from one??
Hershini Gadaria
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Posted: 9 months ago Jul 21, 2023, 4:49 a.m. EDT
  1. You can see which domains are assigned to a material by clicking on the material name. The domains seem to be correctly defined. The overriding of the materials also seem to be correct. I have attached the file with this reply. If you can take a look at it and help me figure out the mistake, I'd greatly appreciate the help
  2. Is the relative permittivity of liquid argon different from one?? Yes, it is 1.505. I changed it to 100 too, to see if it makes any difference. It didn't
>1. You can see which domains are assigned to a material by clicking on the material name. > The domains seem to be correctly defined. The overriding of the materials also seem to be correct. I have attached the file with this reply. If you can take a look at it and help me figure out the mistake, I'd greatly appreciate the help >2. Is the relative permittivity of liquid argon different from one?? Yes, it is 1.505. I changed it to 100 too, to see if it makes any difference. It didn't

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Dave Greve Certified Consultant
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Posted: 9 months ago Jul 21, 2023, 4:46 p.m. EDT

I don't have the semicondutor module but in any case your posted file only has the electrostatic module active.

Under the Charge Conservation node you have selected User Defined for the permittivity and have assigned the same value to all regions. This overrides the material properties so any change to those will have no effect.

Further thoughts:

The argon domain has way more mesh elements than make sense.

This is a symmetric problem and can be reduced in size by a factor of 8.

I don't have the semicondutor module but in any case your posted file only has the electrostatic module active. Under the Charge Conservation node you have selected User Defined for the permittivity and have assigned the same value to all regions. This overrides the material properties so any change to those will have no effect. Further thoughts: The argon domain has way more mesh elements than make sense. This is a symmetric problem and can be reduced in size by a factor of 8.
Edgar J. Kaiser Certified Consultant
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Posted: 9 months ago Jul 22, 2023, 1:57 p.m. EDT

Even if you change the permittivity, the field in the electrostatic model will not change with fixed potential boundaries.

-------------------
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Even if you change the permittivity, the field in the electrostatic model will not change with fixed potential boundaries.

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