Prediction of Monte Carlo errors by a theory generalized to treat track-length estimators

Journal Article · Wed Feb 01 04:00:00 EST 1978 · Nucl. Sci. Eng.; (United States)

OSTI ID:5081822

Booth, T E ^[1]; Amster, H J

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1. Los Alamos Scientific Lab., NM

Present theories for predicting expected Monte Carlo errors in neutron transport calculations apply to estimates of flux-weighted integrals sampled directly by scoring individual collisions. To treat track-length estimators, the recent theory of Amster and Djomehri is generalized to allow the score distribution functions to depend on the coordinates of two successive collisions. It has long been known that the expected track length in a region of phase space equals the expected flux integrated over that region, but that the expected statistical error of the Monte Carlo estimate of the track length is different from that of the flux integral obtained by sampling the sum of the reciprocals of the cross sections for all collisions in the region. These conclusions are shown to be implied by the generalized theory, which provides explicit equations for the expected values and errors of both types of estimators. Sampling expected contributions to the track-length estimator is also treated. Other general properties of the errors for both estimators are derived from the equations and physically interpreted. The actual values of these errors are then obtained and interpreted for a simple specific example.

• OSTI ID: 5081822
• Journal Information: Nucl. Sci. Eng.; (United States), Journal Name: Nucl. Sci. Eng.; (United States) Vol. 65:2; ISSN NSENA
• Country of Publication: United States
• Language: English

Related Subjects

654003* -- Radiation & Shielding Physics-- Neutron Interactions with Matter
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ERRORS
MONTE CARLO METHOD
NEUTRON FLUX
NEUTRON TRANSPORT THEORY
RADIATION FLUX
TRANSPORT THEORY