Keyword:SENSITIVITY

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SENSITIVITY xsens xnsen1 insen3 insen4
parent(i) daughter(i) i=1,insen3
nuclide(j) j=1,insen4


This keyword allows sensitivity calculations to be performed. The sensitivity Monte-Carlo calculation is undertaken over all the irradiation steps and is initiated by the ZERO keyword. Time dependent flux amplitude, flux spectra and cross-sections are permitted in sensitivity runs.

If xsens = LAMBDA then the sensitivity coefficients with respect to decay constant are calculated. If xsens = SIGMA then the sensitivity coefficients with respect to cross section are calculated. However, only one of these options can be specified for a case, the keyword must not be input twice. In the Release 3.00 version the LAMBDA option is not available.

The cut-off value xnsen1 is the magnitude of the correlation coefficient (≤ 1.0) value below which results are not printed. A typical value may be 0.8. The independent variables for the Monte-Carlo calculations are the reactions defined by insen3 parent-daughter pairs. To include fission use the name Fission or number 0 for the daughter nuclide name.

For each of the insen4 nuclides specified the sensitivity of that nuclide to each of the insen3 cross sections or decay constants is calculated.

If insens4 is set to 0, then the merged list of dominant nuclides (i.e., all nuclides that appear on any of the dominant lists) is used as the nuclide list.

Example usage:

< -- Control phase -- >
...
FISPACT
* Title of the simulation
< -- Initial phase -- >
...
SENSITIVITY SIGMA 0.8 2 1
Ti48 Sc48
Ti49 Sc48
Sc48
MCSAMPLE 2 100 -2.0 2.0
...
< -- Inventory phase -- > 
...

I this case, the sensitivity of the Sc48 inventory to the Ti48(n,p)Sc48 and Ti49(n,np+d)Sc48 reactions are used for Monte-Carlo sampling. 100 samples of each is used with a normal distribution between -2 and +2 standard deviations. Note that when insens4 = 0 is used, the number of nuclides displayed may be controlled by the SORTDOMINANT keyword.