Speaker
Dr
Stuart Ansell
(European Spallation Source ERIC)
Description
MCNP(X) Monte Carlo neutronic modeling has now reached the level that
large simulations of spallation sources from proton beam to instrument
detectors and shielding, or reactor core to detectors, in which the
majority of the engineering aspect (e.g. pipework) are described in
detail. Directly building an MCNP(X)'s input for a large geometry, is
highly time consuming and almost all the features of MCNP(X) that
allow that process to be made simpler for the user (e.g. universes,
lattices etc) reduce the simulation runtime performance
by orders of magnitude.
CombLayer is a toolbox designed to facilitate the rapid production of
complex MCNP(X) models that depend on a long list of ranged variables
and a number of module flags. However, to further develop this, we
report in this paper on the development of automated activation
calculation for highly complex models. We have combined this with
Cinder and MCNP to produce a rapid gamma emission flux for a desired
volume, without requiring the user to consider the volumes contents.
There are two elements for such a program: first a significant part of
bookkeeping to manage several thousand individual material cells
separate, and second the overlay of a mesh flux to create a flux
density gradient within cells that have large variation of flux within
an individual cell. This mesh is then used in combination of the cell
based cinder output to populate the gamma emission volume, passed back to
MCNP(X) to produce a gamma dose map at the correct time step after irradiation
A few examples from the ESS and ISIS beamlines will be shown to
show highlight features that would be easily overlooked in a more traditional
cell by cell approach.
The code is publicly available at https://github.com/SAnsell/CombLayer.
Primary author
Dr
Stuart Ansell
(European Spallation Source ERIC)
Co-authors
Dr
Günter Muhrer
(European Spallation Source ERIC)
Dr
Phil Bentley
(ESS)
