Troubleshooting MCNP6.2 Error: l_list Too Small

[angweieng]

TL;DR Summary

MCNP error code: bad trouble in subroutine mars_xs_init of imcn

Hi everyone,

I have used MCNP6.2 for few years. This is the first time that I encountered the error such as below:

bad trouble in subroutine mars_xs_init of imcn
l_list too small.

I tried to run an input deck and track a bunch of decay isotopes. Is anyone has similar error before? If you do, do you know what's the problem of this error? Thank you so much!

 

[Alex A]

I am out of my depth and posting only because no-one better has replied yet.

'mars' is a method used for ray tracing charged particles through a magnetic field. Do you have bfld and bflcl input cards?

If that doesn't help I can only suggest you post a minimal input file that produces the error and maybe someone will see the problem.

 

[raining Pete]

Hi there,

I'm sorry to hear that you're encountering this error in MCNP6.2. I haven't personally encountered this error before, but I did some research and found that this error usually occurs when there are too many isotopes in your input deck. One solution that I found is to increase the size of the l_list parameter in the input deck. You can also try reducing the number of isotopes in your input deck to see if that helps.

I hope this helps and that you're able to resolve the issue. Let me know if you have any other questions or if this solution works for you. Good luck!