# How to make a cylindrical neutron source with a spallation neutron spectrum?

**URL:** <https://openmc.discourse.group/t/how-to-make-a-cylindrical-neutron-source-with-a-spallation-neutron-spectrum/5049>\
**Category:** New Ideas\
**Created:** [December 9, 2024, 1:35pm UTC](https://openmc.discourse.group/t/how-to-make-a-cylindrical-neutron-source-with-a-spallation-neutron-spectrum/5049 "2024-12-09T13:35:18Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![chentiqi](https://avatars.discourse-cdn.com/v4/letter/c/ce7236/32.png) [@chentiqi](https://openmc.discourse.group/u/chentiqi)\
**Post date:** [December 9, 2024, 1:35pm UTC](https://openmc.discourse.group/t/how-to-make-a-cylindrical-neutron-source-with-a-spallation-neutron-spectrum/5049/1 "2024-12-09T13:35:18Z")

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Hi, every. I am doing a simulation about ADS with openmc now. But I have a problem about how to make a cylindrical neutron source with a known spallation neutron spectrum?  
I want a cylindrical neutron source, the neutrons given by this source have different energy, and for each group of neutron has different possibility.  
Thank you everyone!