# User Support **URL:** https://festim.discourse.group/c/general/4.md?page=2 [Latest](https://festim.discourse.group/latest.md) · [Categories](https://festim.discourse.group/categories.md) · [Tags](https://festim.discourse.group/tags.md) **Page:** 3 --- ## [Chemical reactions](https://festim.discourse.group/t/chemical-reactions/92)
**Author:** [@HelenS](https://festim.discourse.group/u/HelenS)\ **Replies:** 8\ **Last updated:** [January 15, 2025, 5:31pm UTC](https://festim.discourse.group/t/chemical-reactions/92 "2025-01-15T17:31:47Z")
Hi again -still a very new user, gradually building up my model! I’m wondering if there is any functionality within FESTIM to do chemical reactions or phase changes - specifically from hydride to mobile solute (as a fun… --- ## [.xdmf from 2D .msh](https://festim.discourse.group/t/xdmf-from-2d-msh/93)
**Author:** [@miklavrent](https://festim.discourse.group/u/miklavrent)\ **Replies:** 3\ **Last updated:** [January 8, 2025, 3:05pm UTC](https://festim.discourse.group/t/xdmf-from-2d-msh/93 "2025-01-08T15:05:56Z")
Happy New Year everyone! I just tried to create .xdmf files from a 2D .msh file using Python script from https://festim.readthedocs.io/en/latest/userguide/mesh.html#converting-meshes-using-meshio And obtained: Traceb… --- ## [Double exports in TXTExport](https://festim.discourse.group/t/double-exports-in-txtexport/58)
**Author:** [@jairrs](https://festim.discourse.group/u/jairrs)\ **Replies:** 8\ **Last updated:** [December 21, 2024, 3:23pm UTC](https://festim.discourse.group/t/double-exports-in-txtexport/58 "2024-12-21T15:23:51Z")
Running this code import festim as F import numpy as np import sympy as sp from matplotlib import pyplot as plt C\_0 = 1 # atom m^-3 D = 1 # 1 m^2 s^-1 profile\_time = 25 # s exact\_solution = C\_0 \* (1 - sp.erf(F.x / sp.s… --- ## [Changing temperature settings at a certain time in the simulation](https://festim.discourse.group/t/changing-temperature-settings-at-a-certain-time-in-the-simulation/73)
**Author:** [@iamryo](https://festim.discourse.group/u/iamryo)\ **Replies:** 11\ **Last updated:** [December 21, 2024, 6:53am UTC](https://festim.discourse.group/t/changing-temperature-settings-at-a-certain-time-in-the-simulation/73 "2024-12-21T06:53:56Z")
Hi! :slightly\_smiling\_face: I am trying to reproduct a series of simulations from plasma irradiation to TDS. But, I faced one problem. During plasma irradiation, sample temperature is transient settings. model.T = F.… --- ## [Outputting data at t = 0](https://festim.discourse.group/t/outputting-data-at-t-0/91)
**Author:** [@HelenS](https://festim.discourse.group/u/HelenS)\ **Replies:** 2\ **Last updated:** [December 18, 2024, 2:21pm UTC](https://festim.discourse.group/t/outputting-data-at-t-0/91 "2024-12-18T14:21:15Z")
How do I output results at time zero, please? adding 0 to this line does not seem to work: F.TXTExport( field=“solute”, times=\[0,1,2,3,1000\], filename=results\_folder + “/mobile\_concentration.txt”, --- ## [Different BCs at different times](https://festim.discourse.group/t/different-bcs-at-different-times/82)
**Author:** [@cruiseraurora](https://festim.discourse.group/u/cruiseraurora)\ **Replies:** 9\ **Last updated:** [December 18, 2024, 2:08pm UTC](https://festim.discourse.group/t/different-bcs-at-different-times/82 "2024-12-18T14:08:35Z")
Hello! I want to simulate D2-gas loading phase, open-air phase and TDS phase. During gas loading and open-air phase, the Sievert’s law should be used, but in the TDS phase I want to apply RecombinationFlux bc. Is it pos… --- ## [The initial flux isn't zero in TDS simulation](https://festim.discourse.group/t/the-initial-flux-isnt-zero-in-tds-simulation/88)
**Author:** [@Jellycarrot](https://festim.discourse.group/u/Jellycarrot)\ **Replies:** 4\ **Last updated:** [December 17, 2024, 5:31pm UTC](https://festim.discourse.group/t/the-initial-flux-isnt-zero-in-tds-simulation/88 "2024-12-17T17:31:15Z")
Hi,I’m doing 1D TDS simulation.The gas is deuterium,and the material is tungsten. I found when I set E\_p near to E\_D(such as E\_p = 0.6 and E\_D = 0 .39),there will be a situation that the initial value of flux is not ze… --- ## [Setting initial H concentration](https://festim.discourse.group/t/setting-initial-h-concentration/90)
**Author:** [@HelenS](https://festim.discourse.group/u/HelenS)\ **Replies:** 2\ **Last updated:** [December 13, 2024, 2:33am UTC](https://festim.discourse.group/t/setting-initial-h-concentration/90 "2024-12-13T02:33:59Z")
I’m afraid I’m a little confused again about sources and initial conditions. I can now use ‘sources’, that introduce some H/m3/s (so the total H continually increases throughout the simulation). I now want to put in just… --- ## [Ratio between concentrations in different materials](https://festim.discourse.group/t/ratio-between-concentrations-in-different-materials/86)
**Author:** [@cruiseraurora](https://festim.discourse.group/u/cruiseraurora)\ **Replies:** 7\ **Last updated:** [November 26, 2024, 1:23pm UTC](https://festim.discourse.group/t/ratio-between-concentrations-in-different-materials/86 "2024-11-26T13:23:29Z")
Hello! Could you please tell me how the concentration jump between different materials is calculated in festim? I expected something like Ca = Sa/Sb \* Cb, where a, b - different materials, C - concentration at the mate… --- ## [The peak of the two-dimensional TDS spectrum can't be reduced to zero](https://festim.discourse.group/t/the-peak-of-the-two-dimensional-tds-spectrum-cant-be-reduced-to-zero/84)
**Author:** [@Jellycarrot](https://festim.discourse.group/u/Jellycarrot)\ **Replies:** 2\ **Last updated:** [November 8, 2024, 12:17pm UTC](https://festim.discourse.group/t/the-peak-of-the-two-dimensional-tds-spectrum-cant-be-reduced-to-zero/84 "2024-11-08T12:17:05Z")
Hi,I’m trying to draw a 2D TDS spectrum of tungsten containing one trap. But I found the total flux need very long time to reach the peak and it won’t reduce to zero while the flux out of the trap drop to 0 very quickly… --- ## [Several volumetric sources of heat](https://festim.discourse.group/t/several-volumetric-sources-of-heat/80)
**Author:** [@miklavrent](https://festim.discourse.group/u/miklavrent)\ **Replies:** 5\ **Last updated:** [November 1, 2024, 1:46pm UTC](https://festim.discourse.group/t/several-volumetric-sources-of-heat/80 "2024-11-01T13:46:24Z")
Hi, Is it possible to have different volumetric sources of heat in different parts of a system? Imagine a two layered first wall with neutrons generating different amount of heat in tungsten and steel. I was only able t… --- ## [Multi-material problem: initial trap distribution and diffusion barrier](https://festim.discourse.group/t/multi-material-problem-initial-trap-distribution-and-diffusion-barrier/71)
**Author:** [@VVKulagin](https://festim.discourse.group/u/VVKulagin)\ **Replies:** 3\ **Last updated:** [August 9, 2024, 2:41pm UTC](https://festim.discourse.group/t/multi-material-problem-initial-trap-distribution-and-diffusion-barrier/71 "2024-08-09T14:41:22Z")
Hi, all! Assume a multi-material problem (for example, W-Cu) with traps defined within one material only. There are two points that I’d like to discuss. 1.If the initial condition for traps is provided with a float, th… --- ## [Multi-material hydrogen permeation 3D model transient solution not converging](https://festim.discourse.group/t/multi-material-hydrogen-permeation-3d-model-transient-solution-not-converging/70)
**Author:** [@jaronfcota](https://festim.discourse.group/u/jaronfcota)\ **Replies:** 5\ **Last updated:** [August 9, 2024, 10:23am UTC](https://festim.discourse.group/t/multi-material-hydrogen-permeation-3d-model-transient-solution-not-converging/70 "2024-08-09T10:23:53Z")
Hello, I am having a bit of trouble with a model converging. I’m trying to model hydrogen permeation through a nickel membrane through molten FLiBe in a cylindrical geometry, and when I try and calculate the transient s… --- ## [Simulation stopping on simple permeation experiment](https://festim.discourse.group/t/simulation-stopping-on-simple-permeation-experiment/69)
**Author:** [@Ignacio-Marcos](https://festim.discourse.group/u/Ignacio-Marcos)\ **Replies:** 8\ **Last updated:** [August 1, 2024, 1:46pm UTC](https://festim.discourse.group/t/simulation-stopping-on-simple-permeation-experiment/69 "2024-08-01T13:46:41Z")
Hi everyone, I’m doing a simple series of permeation experiments with a set of different values for each parameter (diffusivity, Temperature and such), specifically, a full factorial DOE. I’m having trouble with the sim… --- ## [A series of simulations from plasma irradiation experiments to TDS](https://festim.discourse.group/t/a-series-of-simulations-from-plasma-irradiation-experiments-to-tds/65)
**Author:** [@iamryo](https://festim.discourse.group/u/iamryo)\ **Replies:** 9\ **Last updated:** [July 30, 2024, 7:01am UTC](https://festim.discourse.group/t/a-series-of-simulations-from-plasma-irradiation-experiments-to-tds/65 "2024-07-30T07:01:24Z")
Hi everyone, I am trying to reproduce a series of plasma irradiation experiments on tungsten and TDS.(The goal is to reproduce the TDS spectrum.) I am trying to reproduce a series of plasma irradiation and TDS with refe… --- ## [Two Layered Monoblock](https://festim.discourse.group/t/two-layered-monoblock/64)
**Author:** [@celyn](https://festim.discourse.group/u/celyn)\ **Replies:** 8\ **Last updated:** [July 24, 2024, 2:31pm UTC](https://festim.discourse.group/t/two-layered-monoblock/64 "2024-07-24T14:31:05Z")
Hi, I’m trying to run a simulation for a two-layer monoblock in 2D, but I think there are issues when applying the mesh that I have created to FESTIM when it comes to applying surface boundary conditions. When plotting … --- ## [Inhomogeneous Dirichlet BC from csv file](https://festim.discourse.group/t/inhomogeneous-dirichlet-bc-from-csv-file/60)
**Author:** [@ehodille](https://festim.discourse.group/u/ehodille)\ **Replies:** 5\ **Last updated:** [July 23, 2024, 7:19am UTC](https://festim.discourse.group/t/inhomogeneous-dirichlet-bc-from-csv-file/60 "2024-07-23T07:19:13Z")
I have a y\[m\],cm\[m-3\] csv file and I would like to apply these values as an inhomogeneous Dirichlet boundary condition along one of the 1D boundary of my domain (here is a small sketch, if understandable). I created a… --- ## [Export point value](https://festim.discourse.group/t/export-point-value/61)
**Author:** [@xinshen](https://festim.discourse.group/u/xinshen)\ **Replies:** 2\ **Last updated:** [July 22, 2024, 1:59pm UTC](https://festim.discourse.group/t/export-point-value/61 "2024-07-22T13:59:23Z")
Hi everyone, I have a few questions when I want to export some values at some specific points using class PointValue. https://festim.readthedocs.io/en/latest/userguide/export\_post\_processing.html Is the coordinate in c… --- ## [Set different temperature at different boundaries](https://festim.discourse.group/t/set-different-temperature-at-different-boundaries/52)
**Author:** [@xinshen](https://festim.discourse.group/u/xinshen)\ **Replies:** 2\ **Last updated:** [June 22, 2024, 1:04am UTC](https://festim.discourse.group/t/set-different-temperature-at-different-boundaries/52 "2024-06-22T01:04:25Z")
Hi all, I’m trying to set different temperature at different boundaries, the code is shown below. From the view by Paraview, it seems that DirichletBC of temperature will be overrided by my\_model.T = F.Temperature(873),… --- ## [Concentration is zero in some subdomains](https://festim.discourse.group/t/concentration-is-zero-in-some-subdomains/51)
**Author:** [@xinshen](https://festim.discourse.group/u/xinshen)\ **Replies:** 8\ **Last updated:** [June 11, 2024, 4:19am UTC](https://festim.discourse.group/t/concentration-is-zero-in-some-subdomains/51 "2024-06-11T04:19:42Z")
Hi everyone. I performed a simulation of hydrogen transport in W/Cu/CuCrZr in 2D. I used big mesh size to make the computation quick. The exported chemical\_pot\_conservation derived\_quantities file show the result. As is… --- ## [Unable to successfully call PETSc function 'KSPSolve'](https://festim.discourse.group/t/unable-to-successfully-call-petsc-function-kspsolve/48)
**Author:** [@xinshen](https://festim.discourse.group/u/xinshen)\ **Replies:** 3\ **Last updated:** [June 5, 2024, 1:04am UTC](https://festim.discourse.group/t/unable-to-successfully-call-petsc-function-kspsolve/48 "2024-06-05T01:04:35Z")
Hi everyone. The code run but the process finished with exit code 1 as below. Line 167 is the last line of the code which is my\_model.run(). I would like to present a MWE to reproduce this error but failed. What can I … --- ## [Problems when reproducing the results of the article](https://festim.discourse.group/t/problems-when-reproducing-the-results-of-the-article/43)
**Author:** [@xinshen](https://festim.discourse.group/u/xinshen)\ **Replies:** 20\ **Last updated:** [May 31, 2024, 1:40am UTC](https://festim.discourse.group/t/problems-when-reproducing-the-results-of-the-article/43 "2024-05-31T01:40:00Z")
Hi everyone, I’m trying to reproduce the results of the article “Influence of interface conditions on hydrogen transport studies” and I have some questions. First, what do “OK TMAP” and “OK MUYI” in the source code mean… --- ## [Second peak in TDS simulation for a single trap](https://festim.discourse.group/t/second-peak-in-tds-simulation-for-a-single-trap/47)
**Author:** [@Jellycarrot](https://festim.discourse.group/u/Jellycarrot)\ **Replies:** 5\ **Last updated:** [May 27, 2024, 9:53am UTC](https://festim.discourse.group/t/second-peak-in-tds-simulation-for-a-single-trap/47 "2024-05-27T09:53:35Z")
Hi， I’m working on thermo-desorption spectra of hydrogen in tungsten with FESTIM.However,there’s a question that troubles me: Why does FESTIM’s TDS simulation for a single trap have a second peak after the first main p… --- ## [Tag the geometry with Salome](https://festim.discourse.group/t/tag-the-geometry-with-salome/45)
**Author:** [@xinshen](https://festim.discourse.group/u/xinshen)\ **Replies:** 4\ **Last updated:** [May 24, 2024, 12:21pm UTC](https://festim.discourse.group/t/tag-the-geometry-with-salome/45 "2024-05-24T12:21:00Z")
Hi all, I have a few questions about tagging the geometry with Salome. I would appreciate it if someone could help me. FESTIM-workshop/tasks/task08.ipynb FESTIM-workshop/tasks/task08.ipynb at main · festim-dev/FESTIM-… --- ## [Add parameter on Advection-diffusion problem](https://festim.discourse.group/t/add-parameter-on-advection-diffusion-problem/41)
**Author:** [@RaphaelCSIR](https://festim.discourse.group/u/RaphaelCSIR)\ **Replies:** 5\ **Last updated:** [April 29, 2024, 11:15am UTC](https://festim.discourse.group/t/add-parameter-on-advection-diffusion-problem/41 "2024-04-29T11:15:40Z")
Hi, I’m working on geological problem and I try to solve a gas transport across a soil. To solve this problem, I want to modify the advection-diffusion equation and by the Fick law (diffusive transport) with porosity a… --- ## [Heat transfer problem: how to set up transient calcumations](https://festim.discourse.group/t/heat-transfer-problem-how-to-set-up-transient-calcumations/39)
**Author:** [@ialoveganicolas](https://festim.discourse.group/u/ialoveganicolas)\ **Replies:** 1\ **Last updated:** [April 19, 2024, 4:55pm UTC](https://festim.discourse.group/t/heat-transfer-problem-how-to-set-up-transient-calcumations/39 "2024-04-19T16:55:10Z")
Hey everyone, I’m trying to set up heat transfer problem in FESTIM for the transient case. There is a good example on the stationary case in the workshop (FESTIM-workshop/tasks/task07.ipynb at main · festim-dev/FESTIM-wo… --- ## [Simulation does not converge when material properties inversely proportional to temperature](https://festim.discourse.group/t/simulation-does-not-converge-when-material-properties-inversely-proportional-to-temperature/36)
**Author:** [@VVKulagin](https://festim.discourse.group/u/VVKulagin)\ **Replies:** 1\ **Last updated:** [April 18, 2024, 6:11pm UTC](https://festim.discourse.group/t/simulation-does-not-converge-when-material-properties-inversely-proportional-to-temperature/36 "2024-04-18T18:11:25Z")
Hello all. I tried setting the temperature-dependent material properties for HeatTransferProblem using the polynomial expressions from this paper. Unfortunately, the simulation model instantly diverges with these expre… --- ## [Parallel computation](https://festim.discourse.group/t/parallel-computation/33)
**Author:** [@VVKulagin](https://festim.discourse.group/u/VVKulagin)\ **Replies:** 4\ **Last updated:** [April 3, 2024, 7:27am UTC](https://festim.discourse.group/t/parallel-computation/33 "2024-04-03T07:27:55Z")
Hi, all! How to properly run a FESTIM simulation in parallel? --- ## [Modeling co-deposited samples](https://festim.discourse.group/t/modeling-co-deposited-samples/28)
**Author:** [@m2patino](https://festim.discourse.group/u/m2patino)\ **Replies:** 1\ **Last updated:** [January 25, 2024, 8:54pm UTC](https://festim.discourse.group/t/modeling-co-deposited-samples/28 "2024-01-25T20:54:38Z")
I’m trying to reproduce the experimental results from Baldwin et al. \[NME 23 (2020) 100743\], where the trap energies and concentrations were used as input for FESTIM. For codeposited samples, is it possible to set the D… --- ## [Concentration depth profiles as input/output](https://festim.discourse.group/t/concentration-depth-profiles-as-input-output/29)
**Author:** [@m2patino](https://festim.discourse.group/u/m2patino)\ **Replies:** 1\ **Last updated:** [January 25, 2024, 8:52pm UTC](https://festim.discourse.group/t/concentration-depth-profiles-as-input-output/29 "2024-01-25T20:52:48Z")
Is it possible to input a D concentration depth profile? Is it possible to output the D concentration depth profile? [Previous page](https://festim.discourse.group/c/general/4.md?page=1) [Next page](https://festim.discourse.group/c/general/4.md?page=3)