Difference between revisions of "Doppler-broadening preprocessor routine"
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* The preprocessor does ''NOT'' adjust the energy grid of the cross section in the temperature adjustment process. Consequently, the resulting energy grid is suboptimal such that | * The preprocessor does ''NOT'' adjust the energy grid of the cross section in the temperature adjustment process. Consequently, the resulting energy grid is suboptimal such that | ||
** the resulting cross section requires slightly more memory than what a cross section processed with NJOY would require at the same temperature and | ** the resulting cross section requires slightly more memory than what a cross section processed with NJOY would require at the same temperature and | ||
| − | ** the reconstruction tolerance of the resulting cross section is unknown. Experience has shown that the errors remain small at least if the nearest library temperature is used as the basis for broadening. | + | ** the reconstruction tolerance of the resulting cross section is unknown. Experience has shown that the errors remain small in practice, at least if the nearest library temperature is used as the basis for broadening. |
Revision as of 12:12, 22 February 2016
Contents
Introduction
Use
Theory
Pitfalls
- The preprocessor does NOT adjust the temperature of thermal scattering data. For moderator materials, the temperature of thermal scattering data must be changed separately by either
- changing the library defined in the therm card or
- interpolating the thermal scattering data between two temperatures using the therm card
- The preprocessor does NOT adjust the temperature of the unresolved region probability tables. When modeling fast systems, the temperature dependence of reaction rates can be modeled (accurately) only by using ACE libraries corresponding to the exact temperature of each material. These ACE libraries can be processed using NJOY.
- The preprocessor does NOT adjust the energy grid of the cross section in the temperature adjustment process. Consequently, the resulting energy grid is suboptimal such that
- the resulting cross section requires slightly more memory than what a cross section processed with NJOY would require at the same temperature and
- the reconstruction tolerance of the resulting cross section is unknown. Experience has shown that the errors remain small in practice, at least if the nearest library temperature is used as the basis for broadening.
