# Run simulation for a given time **URL:** \ **Category:** User Support\ **Created:** [October 27, 2022, 2:30pm UTC](https://openmc.discourse.group/t/run-simulation-for-a-given-time/2395 "2022-10-27T14:30:08Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Daniel\_Lopez](https://avatars.discourse-cdn.com/v4/letter/d/8491ac/32.png) [@Daniel\_Lopez](https://openmc.discourse.group/u/Daniel_Lopez)\ **Post date:** [October 27, 2022, 2:30pm UTC](https://openmc.discourse.group/t/run-simulation-for-a-given-time/2395/1 "2022-10-27T14:30:08Z")
Hi all, I’m a little new using the software and I have a general question about simulating a neutron distribution for a given time. I have noticed that one can see the tracks, energy and time for a number of particles in the simulation output.h5. But, ¿there is a way to run the simulation for a given time in seconds?.I would like to save the state of the particles i.e, the neutron distribution, tracks, energies at that given time and then reuse them to resume the simulation after adjust some parameters of the volume and density distribution. Thank you in advance. ---
**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 27, 2022, 8:30pm UTC](https://openmc.discourse.group/t/run-simulation-for-a-given-time/2395/2 "2022-10-27T20:30:00Z")
@Daniel_Lopez Interesting question. Right now I don’t believe we have any way to stop particles at a given time to collect them, although that would be an interesting feature for transient applications. Are you aware of other MC codes that have a similar feature? I would be interested to see what the use of such a feature would look like from a user’s perspective. ---
**Author:** ![yrrepy](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/yrrepy/32/2365_2.png) [@yrrepy](https://openmc.discourse.group/u/yrrepy)\ **Post date:** [October 28, 2022, 6:20pm UTC](https://openmc.discourse.group/t/run-simulation-for-a-given-time/2395/3 "2022-10-28T18:20:20Z")
CTME Computer Time Cutoff Card in MCNP, no? ---
**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 28, 2022, 6:38pm UTC](https://openmc.discourse.group/t/run-simulation-for-a-given-time/2395/4 "2022-10-28T18:38:40Z")
Ah yes, I guess we need clarification. @Daniel_Lopez are you talking about physical time (from the particle’s perspective)? or a runtime cutoff (i.e., run the simulation for 10 minutes before stopping)? I assumed the former, but perhaps that was an incorrect assumption. ---
**Author:** ![Daniel\_Lopez](https://avatars.discourse-cdn.com/v4/letter/d/8491ac/32.png) [@Daniel\_Lopez](https://openmc.discourse.group/u/Daniel_Lopez)\ **Post date:** [October 28, 2022, 7:55pm UTC](https://openmc.discourse.group/t/run-simulation-for-a-given-time/2395/5 "2022-10-28T19:55:04Z")
@paulromano and @yrrepy thank you for answering so fast. Yes, I was talking about physical time from the particle’s perspective. I mean, I would like to update the neutron distribution for, say, 1e-6 seconds, save the state and then run again with some parameters adjusted. Thank you again. ---
**Author:** ![Daniel\_Lopez](https://avatars.discourse-cdn.com/v4/letter/d/8491ac/32.png) [@Daniel\_Lopez](https://openmc.discourse.group/u/Daniel_Lopez)\ **Post date:** [February 9, 2023, 11:58pm UTC](https://openmc.discourse.group/t/run-simulation-for-a-given-time/2395/6 "2023-02-09T23:58:04Z")
> [@Daniel\_Lopez](#): > > conds, save the state and then run again with some parameters adjusted. > Thank you again. Hello! Thank you again for your answers. I was thinking about a way to do this and I read the docs section about tracking particles. I saw the time parameter and that one can also apply a probability distribution of times. I wanted to ask you if maybe this could be used to obtain parameters that depends of time like in this paper. [https://arxiv.org/pdf/2107.11197.pdf](https://arxiv.org/pdf/2107.11197.pdf) Thank you a lot for your help! Daniel