# Question on Fixed source

**URL:** <https://openmc.discourse.group/t/question-on-fixed-source/813>\
**Category:** User Support\
**Created:** [October 14, 2020, 10:08am UTC](https://openmc.discourse.group/t/question-on-fixed-source/813 "2020-10-14T10:08:31Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Pattarapol](https://avatars.discourse-cdn.com/v4/letter/p/5daacb/32.png) [@Pattarapol](https://openmc.discourse.group/u/Pattarapol)\
**Post date:** [October 14, 2020, 10:08am UTC](https://openmc.discourse.group/t/question-on-fixed-source/813/1 "2020-10-14T10:08:31Z")

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Hi, all  
I’ve got some questions on OpenMC. Can OpenMC run fixed source calculations using an external source file? Is there any example of a fixed source calculations using an external source file?

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**Author:** ![paulromano](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/paulromano/32/486_2.png) [@paulromano](https://openmc.discourse.group/u/paulromano)\
**Post date:** [October 15, 2020, 11:37am UTC](https://openmc.discourse.group/t/question-on-fixed-source/813/2 "2020-10-15T11:37:47Z")

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@Pattarapol It appears that fixed source calculations using an external source file is not currently possible. That being said, it doesn’t look like it would be terribly difficult to enable this. I’ve created an [ssue](https://github.com/openmc-dev/openmc/issues/1692) to keep track of this.