Invariant embedding and related methods

Journal Article · Sat Dec 31 04:00:00 EST 1994 · Transactions of the American Nuclear Society

OSTI ID:89112

Nelson, P

The term {open_quotes}invariant embedding{close_quotes} derives from the fact that if a physical system is linear, in the sense that certain identified {open_quotes}output{close_quotes} properties (e.g., exiting fluxes) depend linearly in the mathematical sense on other {open_quotes}input{close_quotes} properties (e.g., entering fluxes), then that property is invariant to the system being embedded into a larger system (i.e., being a subsystem of such larger system). The basic idea of such {open_quotes}principles of invariance{close_quotes} go back at least to early work of Stokes, who applied them to radiative transfer (of light). The first application to nuclear radiation seems to have occurred in a 1907 paper of Schmidt. Although invariant embedding is often viewed as inherently limited to one-dimensional settings, at the level of generality described here, the well-known response matrix method (e.g., Weiss), which has been used for multidimensional radiation transport computations and recently even has been shown to be well suited to such computations on massively parallel systems, is an instance of invariant embedding. Ribarit has described an elaborate and fairly abstract calculus for (among other things) computing the input - output structures of any given (neutronic) system from those of a set of constituent subsystems.

• OSTI ID: 89112
• Report Number(s): CONF-941102--
• Journal Information: Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 71; ISSN 0003-018X; ISSN TANSAO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
INVARIANT IMBEDDING
NEUTRON TRANSPORT
NEUTRON TRANSPORT THEORY