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MCNP errors

  1. Sep 11, 2015 #1
    After running MCNP5, the output run terminated because 10 particles got lost
    how i can fix this problem ?
  2. jcsd
  3. Sep 11, 2015 #2


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    Education Advisor
    Gold Member

    The most likely thing is you have a problem in your geometry. Someplace you have a volume that is not part of a cell. Read your output file. Also, look in the user manual to see how to get it to output the track information for particles. What you want to find out is where a particle was when it got lost. That should give you a clue as to where there is a problem in your geometry. Every volume must be in a defined cell. You must not have any volume that is undefined. Also, every volume must be in exactly one cell. You can't have any volumes that are in two or more cells.

    A frequent place to get into trouble is in arrays. You may not have defined the unit cell the way you thought. So it may not fill the volume you thought.

    Another place to get in trouble is when you are doing a cell and the complement. You may have defined the outside of a cell differently from how you thought.

    Look for places where you have unusual or irregular shapes, especially where they bound other irregular shapes.

    Use the vised editor to help you figure out what cells are not properly defined. One of the tell-tales that vised shows is a dotted line at the boundary of a cell. That usually indicates a problem in the geometry.
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