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| author | stainer_t <thomas.stainer@oecd-nea.org> | 2025-09-08 13:48:49 +0200 |
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| committer | stainer_t <thomas.stainer@oecd-nea.org> | 2025-09-08 13:48:49 +0200 |
| commit | 7dfcc480ba1e19bd3232349fc733caef94034292 (patch) | |
| tree | 03ee104eb8846d5cc1a981d267687a729185d3f3 /doc/IGE335/Section3.06_asm.tex | |
Initial commit from Polytechnique Montreal
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diff --git a/doc/IGE335/Section3.06_asm.tex b/doc/IGE335/Section3.06_asm.tex new file mode 100644 index 0000000..fe7d5e7 --- /dev/null +++ b/doc/IGE335/Section3.06_asm.tex @@ -0,0 +1,144 @@ +\subsection{The {\tt ASM:} module}\label{sect:ASMData} + +We will now describe the assembly modules which can be used to prepare the +group-dependent complete collision probability or the assembly matrices required +by the flux solution module of DRAGON. The assembly module {\tt ASM:} is +generally called after a tracking module; it recovers tracking lengths and +material numbers from the sequential tracking file and then computes the +collision probability or group--dependent system matrices under various +normalizations. The calling specifications are: + +\begin{DataStructure}{Structure \dstr{ASM:}} +\dusa{PIJNAM} \moc{:=} \moc{ASM:} $[$ \dusa{PIJNAM} $]$ \dusa{LIBNAM} +\dusa{TRKNAM} $[$ \dusa{TRKFIL} $]$ \moc{::} \dstr{descasm} +\end{DataStructure} + +\noindent where +\begin{ListeDeDescription}{mmmmmmmm} + +\item[\dusa{PIJNAM}] {\tt character*12} name of \dds{asmpij} data +structure containing the system matrices. If \dusa{PIJNAM} appears on the RHS, +the \dstr{descasm} information previously stored in \dusa{PIJNAM} is kept. + +\item[\dusa{LIBNAM}] {\tt character*12} name of the \dds{macrolib} or +\dds{microlib} data structure that contains the +macroscopic cross sections (see \Sectand{MACData}{LIBData}). + +\item[\dusa{TRKNAM}] {\tt character*12} name of the \dds{tracking} data +structure containing the tracking (see \Sect{TRKData}). + +\item[\dusa{TRKFIL}] {\tt character*12} name of the sequential binary tracking +file used to store the tracks lengths. This file is given if and only if it was +required in the previous tracking module call (see \Sect{TRKData}). + +\item[\dstr{descasm}] structure containing the input data to this module (see +\Sect{descasm}). + +\end{ListeDeDescription} + +\subsubsection{Data input for module {\tt ASM:}}\label{sect:descasm} + +\begin{DataStructure}{Structure \dstr{descasm}} +$[$ \moc{EDIT} \dusa{iprint} $]$ \\ +$[$ $\{$ \moc{ARM} $|$ \\ +~~~~$\{$ \moc{PIJ} $|$ \moc{PIJK} $\}$ $[$ \moc{SKIP} $]$ \\ +~~~~$[$ $\{$ \moc{NORM} $|$ \moc{ALBS} $\}$ $]$ \\ +~~~~$[$ \moc{PNOR} $\{$ \moc{NONE} $|$ \moc{DIAG} $|$ \moc{GELB} $|$ \moc{HELI} $|$ \moc{NONL} $\}$ $]$ \\ +$\}$ $]$ \\ +$[~\{$ \moc{ECCO} $|$ \moc{HETE} $\}~]$ \\ +{\tt ;} +\end{DataStructure} + +\noindent +where + +\begin{ListeDeDescription}{mmmmmmmm} + +\item[\moc{EDIT}] keyword used to modify the print level \dusa{iprint}. + +\item[\dusa{iprint}] index used to control the printing of this module. The +amount of output produced by this tracking module will vary substantially +depending on the print level specified. + +\item[\moc{ARM}] keyword to specify that an assembly calculation is carried out without +building the full collision probability matrices. This option can only be used for a geometry +tracked using the interface current method (with EURYDICE-2 option within \moc{SYBILT:} or +with the multicell surfacic approximation within \moc{SALT:}), \moc{MCCGT:} or \moc{SNT:} module. +By default, the \moc{PIJ} option is used. + +\item[\moc{PIJ}] keyword to specify that the standard scattering-reduced collision +probabilities must be computed. This option cannot be used with the \moc{MCCGT:} and \moc{SNT:} +modules. This is the default option. + +\item[\moc{PIJK}] keyword to specify that both the directional and standard +scattering-reduced collision probabilities must be computed. Moreover, the additional directional +collision probability matrix can only be used if \moc{HETE} is activated in +\Sect{FLUData}. Finally, the \moc{PIJK} +option is only available for 2--D geometries analyzed with the operator +\moc{EXCELT:} with collision probability option. By default, the \moc{PIJ} +option is used. + +\item[\moc{SKIP}] keyword to specify that only the reduced collision +probability matrix $p^{g}_{ij}$ is to be computed. In general, the scattering +modified collision probability matrix $p^{g}_{s,ij}$ is also computed using: + $$ +p^{g}_{s,ij}=\left[ I-p^{g}_{ij} \Sigma^{g\to g}_{s0} \right] ^{-1} +p^{g}_{ij} + $$ +where $\Sigma^{g\to g}_{s0}$ is the within group isotropic scattering cross +section. When available, $p^{g}_{s,ij}$ is used in the flux solution module in +such a way that for the groups where there is no up-scattering, the thermal +iteration is automatically deactivated. In the case where the \moc{SKIP} option +is activated, the $p^{g}_{ij}$ matrix is used and thermal iterations are +required in every energy group. Consequently, the total number of inner +iterations is greatly increased. + +\item[\moc{NORM}] keyword to specify that the scattering-reduced collision probability matrix is +to be normalized in such a way as to eliminate all neutron loss (even if the +region under consideration has external albedo boundary conditions which should +result in neutron loss). When used with a void boundary condition (zero reentrant +current), this option is equivalent to imposing {\it a posteriori} a uniform +reentrant current. + +\item[\moc{ALBS}] keyword to specify that a consistent Selengut normalization +of the scattering-reduced collision probability matrix is to be used both for the flux solution +module (see \Sect{FLUData}) and in the equivalence calculation (see +\Sect{EDIData}). This keyword results in storing the scattering-reduced escape probabilities +$W_{iS}$ in the record named {\tt 'DRAGON-WIS'}. For all the cases where this option is used, it is necessary to +define a geometry with \moc{VOID} external boundary conditions (see +\Sect{GEOData}). + +\item[\moc{PNOR}] keyword to specify that the collision, leakage and escape +probability matrices are to be normalized in such a way as to satisfy explicitly +the neutron conservation laws. This option compensates for the errors which will +arise in the numerical evaluation of these probabilities and may result in +non-conservative collision probability matrices. The default option is now \moc{HELI} while it was +formerly \moc{GELB} ({\bf Revision 3.03}). + +\item[\moc{NONE}] keyword to specify that the probability matrices are not to +be renormalized. + +\item[\moc{DIAG}] keyword to specify that only the diagonal element of the +probability matrices will be modified in order to insure the validity of the +conservation laws. + +\item[\moc{GELB}] keyword to specify that the Gelbard algorithm will be used +to normalize the collision probability matrices.\cite{RENOR} + +\item[\moc{HELI}] keyword to specify that the Helios algorithm will be used +to normalize the collision probability matrices.\cite{Helios} + +\item[\moc{NONL}] keyword to specify that a non-linear multiplicative +algorithm will be used to normalize the collision probability +matrices.\cite{RENOR} + +\item[\moc{ECCO}] keyword used to compute the $P_1$--scattering reduced +collision probability or system matrices required by the ECCO isotropic +streaming model. By default, this information is not calculated. + +\item[\moc{HETE}] keyword used to compute the information required by a +method of characteristics (MOC) solution of the TIBERE anisotropic +streaming model. By default, this information is not calculated. + +\end{ListeDeDescription} +\eject |
