Creating FMESH Tally Over Region - Troubleshooting

  • Thread starter nrat320
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In summary, the conversation discusses the creation of a FMESH tally for energy deposition over a region with specific boundaries. The input code is provided, but the meshtal file only shows three significant figures and the user is wondering if this is due to the boundary resolution or incorrect writing of boundaries. There is no information in the manual about boundary resolution.
  • #1
nrat320
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TL;DR Summary
My FMESH bounds are not right
I am trying to create a FMESH tally over a region that's (x: -15um to 15um, y:-15um to 15um, z:10um to 60um). My input code is below:

FC4 FMESH tally energy deposition
FMESH4:E GEOM=xyz ORIGIN= -0.0015 -0.0015 0.0010 &
IMESH=0.0015 IINTS=10 &
JMESH=0.0015 JINTS=1 &
KMESH=0.0060 KINTS=10 &
OUT=ik

However the meshtal file does not show more than 3 sigfigs (the meshtal output is shown below):

Tally bin boundaries:
X direction: -0.00 -0.00 -0.00 -0.00 -0.00 0.00 0.00 0.00 0.00 0.00 0.00
Y direction: -0.00 0.00
Z direction: 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01
Energy bin boundaries: 1.00E-05 1.00E+01

I couldn't anything about boundary resolution in the manual. Is FMESH incapable of calculating for small area or am I writing the boundaries incorrectly?
 
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  • #2

It seems like you are having trouble with the boundary resolution in your FMESH tally. The output only shows 3 significant figures, which could be an indication that the program is not capable of calculating for such a small area. I would recommend checking the manual or reaching out to the program's technical support team for more information on boundary resolution and if there are any limitations for small areas in FMESH. It is also possible that you are writing the boundaries incorrectly, so double-checking your input code and making sure it matches the program's requirements could also be helpful.
 

FAQ: Creating FMESH Tally Over Region - Troubleshooting

How do I define the region for an FMESH tally in my simulation?

To define the region for an FMESH tally, you need to specify the boundaries of the mesh in your input file. This typically involves setting the x, y, and z coordinates that define the corners of the mesh. Ensure that your region encompasses the area of interest and that the mesh resolution is appropriate for the level of detail you require.

Why is my FMESH tally not producing any data?

If your FMESH tally is not producing data, check the following: ensure that the tally is correctly defined in your input file, verify that the region of the mesh overlaps with the source or the area where particles are expected, and make sure that the simulation has run for enough time to collect meaningful data. Additionally, check for any errors or warnings in the output file that might indicate issues with the tally setup.

How can I improve the resolution of my FMESH tally results?

To improve the resolution of your FMESH tally results, you can increase the number of divisions in the mesh. This means specifying a finer grid by increasing the number of bins along the x, y, and z axes. Be cautious, as increasing the resolution will also increase the computational load and may require more memory and processing time.

What do I do if my FMESH tally results are unexpectedly high or low?

If your FMESH tally results are unexpectedly high or low, first verify that the tally region is correctly defined and that the mesh accurately represents the physical geometry of the problem. Check for any possible errors in the input file, such as incorrect material properties or source definitions. It might also be helpful to perform a simpler test case to ensure the tallying system is working correctly before applying it to more complex scenarios.

Can I use FMESH tallies for multiple regions in a single simulation?

Yes, you can use FMESH tallies for multiple regions in a single simulation. You need to define separate FMESH tally entries for each region in your input file, ensuring that each has a unique identifier and specified boundaries. This allows you to collect detailed data from different areas of interest within the same simulation run.

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