Comparison of Direct and Adjoint k and α-Eigenfunctions
| Autor: | Patrick Blaise, Andrea Zoia, Alexis Jinaphanh, Florent Chevallier, Vito Vitali |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Physics
Work (thermodynamics) α Fission 020209 energy Mathematical analysis Monte Carlo method TK9001-9401 eigenvalues G-IFP eigenfunctions 02 engineering and technology Eigenfunction 01 natural sciences IFP 010305 fluids & plasmas Criticality Power iteration Iterated function 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Nuclear engineering. Atomic power k Monte Carlo Eigenvalues and eigenvectors |
| Zdroj: | Journal of Nuclear Engineering, Vol 2, Iss 14, Pp 132-151 (2021) Journal of Nuclear Engineering Volume 2 Issue 2 Pages 14-151 |
| ISSN: | 2673-4362 |
| Popis: | Modal expansions based on k-eigenvalues and α-eigenvalues are commonly used in order to investigate the reactor behaviour, each with a distinct point of view: the former is related to fission generations, whereas the latter is related to time. Well-known Monte Carlo methods exist to compute the direct k or α fundamental eigenmodes, based on variants of the power iteration. The possibility of computing adjoint eigenfunctions in continuous-energy transport has been recently implemented and tested in the development version of TRIPOLI-4®, using a modified version of the Iterated Fission Probability (IFP) method for the adjoint α calculation. In this work we present a preliminary comparison of direct and adjoint k and α eigenmodes by Monte Carlo methods, for small deviations from criticality. When the reactor is exactly critical, i.e., for k0 = 1 or equivalently α0 = 0, the fundamental modes of both eigenfunction bases coincide, as expected on physical grounds. However, for non-critical systems the fundamental k and α eigenmodes show significant discrepancies. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|