iFunc_Sqw2D and iData_Sqw2D: multi-scattering method #190
Description
iFunc_Sqw2D / iData_Sqw2D multiple scattering evaluation
- get a Sqw2D model
- feval and create an iData_Sqw2D
- write it as .sqw file
- build an McCode model from McStas Sqw monitor https://github.com/McStasMcXtrace/McCode/blob/master/mcstas-comps/examples/Test_Monitor_Sqw.instr
- use .sqw, geometry and XS "sigma" parameters
- compute and return multi-scattering over total scattering