Two "collision biasing" schemes have been tested in a major production, Monte Carlo neutron and photon transport code MCNP. The intent is to reduce the variance that is inherent in all Monte Carlo calculations and increase the Monte Carlo efficiency in problems where the phase space is not sampled adequately. The first scheme, called collision biasing, already exists in the French code TRIPOLI. This method samples several post-collision coordinates and randomly selects one in proportion to an input importance function. The second scheme, called track biasing, is original and differs from collision biasing in that several particle tracks (trajectories) are sampled from one distance-to-collision calculation to the next distance-to-collision calculation, and one is chosen randomly in proportion to an input importance function. The effect of track biasing was found to be problem dependent. For transport along a long narrow cylinder the Monte Carlo efficiency increased, however for a deep penetration problem it decreased.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/277288 |
| Date | January 1990 |
| Creators | Brown, Robert Springer, 1958- |
| Contributors | Filippone, William L. |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Thesis-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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