MCNP6 Gets Correlated with CGM 3.4 - Paper 41
- Los Alamos National Laboratory, Bikini Atoll Rd. P.O. Box 1663, MS-C921, Los Alamos, NM 87545 (United States)
Version 3.4 of the Cascading Gamma-ray Multiplicity (CGM) code has been integrated into version 6 of the Monte Carlo radiation transport code MCNP. The current release is MCNP6 which is the merger of MCNPX 2.7.0 and MCNP5. MCNP6 is a general purpose Monte Carlo radiation transport code that can transport 34 different particles and heavy ions. CGM was originally integrated into MCNPX 2.7.0 as an undocumented feature, but was never released to the public. With the integration of CGM into MCNP6 the code now has the capability of producing correlated secondary particle/gamma emissions and should be available in future release of MCNP. Before the integration of CGM, MCNP only used libraries that contain the total multiplicity but not the multiplicity distribution or the correlations. Lacking this information requires the code to use integer sampling to determine the multiplicity. In the example of thermal neutron capture on Cl-35, presented in the results section, MCNP does integer sampling. This means MCNP would produce one gamma 17% of the time and two gammas 82% giving a mean multiplicity of 1.83. Using CGM, MCNP can now produce a spectrum of multiplicities. The use of CGM has several advantages over the use of ACE data libraries in MCNP6: 1) it has correlated gamma production, 2) it produces a distribution of gamma multiplicities per interaction, whereas ACE produces an average between two integer multiplicities, 3) it is a theoretical model that may predict experimentally unmeasured physical quantities that may not be in experimental based data libraries. CGM conserves energy and angular momentum internally to CGM; however, angular emission information is not currently sent back to MCNP6. Future work will include the integration of correlated neutrons from CGM. Also, the reaction type will be passed to CGM to set the spin and parity for a particular reaction when possible. (authors)
- Research Organization:
- American Nuclear Society - ANS, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
- OSTI ID:
- 23082883
- Resource Relation:
- Conference: RPSD 2014: 18. Topical Meeting of the Radiation Protection and Shielding Division of ANS, Knoxville, TN (United States), 14-18 Sep 2014; Other Information: Country of input: France; 5 refs.; available on CD Rom from American Nuclear Society - ANS, 555 North Kensington Avenue, La Grange Park, IL 60526 (US)
- Country of Publication:
- United States
- Language:
- English
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