Transfer matrix treatments for multigroup Monte Carlo calculations: the elimination of ray effects

Journal Article · Thu Jan 01 04:00:00 EST 1976 · Nucl. Sci. Eng., v. 59, no. 1, pp. 27-45

OSTI ID:4097318

Carter, L L; Forest, C A

The coefficients of a truncated Legendre series are usually used in multigroup cross-section sets to describe the angular distribution for a group-to- group scattering event. Discrete ordinates codes use the truncated Legendre series because this representation of the scattering angle can be used with the addition theorem to conveniently treat the scattering source term. However, the truncated Legendre series has inherent disadvantages for Monte Carlo calculations. Discussions are presented of the truncated Legendre series representation, a discrete angle representation, a step function representation, and an exact representation that is applicable for isotropic scattering in the center-of-mass system. The three approximate representations use the coefficients of a truncated Legendre series as a working base. A sample problem shows that the step function representation has advantages for multigroup Monte Carlo calculations, and its inclusion as an option in multigroup codes is recommended. (auth)

• Research Organization: Los Alamos Scintific Lab., NM
• NSA Number: NSA-33-019587
• OSTI ID: 4097318
• Journal Information: Nucl. Sci. Eng., v. 59, no. 1, pp. 27-45, Journal Name: Nucl. Sci. Eng., v. 59, no. 1, pp. 27-45; ISSN NSENA
• Country of Publication: United States
• Language: English

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