Sensitivity calculations

Serpent relies on the collision history based first order GPT equivalent implementation to calculate sensitivities of various responses to various perturbations. As a simple example, the sensitivity of the effective multiplication factor to the different nuclear cross sections can be calculated.

Input

Adding a response

set sensresp NAME FLAG

Where the different response names and flags are as follows

Adding a perturbation

set senspert NAME FLAG

Where the different perturbation names and flags are as follows

NAME	explanation of NAME	FLAG	explanation of FLAG
xs	perturbation of basic cross sections	0/1	OFF/ON
chi	perturbation of fission spectrum	0/1	OFF/ON
nubar	perturbation of fission nubar	0/1	OFF/ON
eleg	perturbation of Legendre moments of elastic scattering angular distribution	0/1/2/3/4/5/6/7	Number of Legendre moments to perturb.

Choosing nuclides to perturb

The perturbed nuclides can be specified by giving a list of the ZAI-numbers to include

set senspert zailist N_ZAI ZAI1 ZAI2 ...  ZAIN_ZAI

for example

set senspert zailist 2 922350 922380

for perturbations affecting ²³⁵U and ²³⁸U. All nuclides present in the calculation can be included with

set senspert zailist all

Additional options

Number of latent generations.

IFP chain length.

Response based tallying or event based tallying.

Event bank.