Neutron polarization

BornAgain takes neutron polarization into account if there is magnetism in the sample model or if a polarizer is set in the instrument model.

Sample magnetization is explained in Sample model > Materials > Magnetization.

Beam polarization is set through

polarizer_dir = R3(x, y, z)
beam.setPolarization(polarizer_dir) # for scattering
scan.setPolarization(polarizer_dir) # for specular and offspec

The polarizer_dir is a Bloch vector, created by the constructor

If it is a unit vector, then the beam polarization is perfect. A shorter vector indicates imperfect polarization.

The analyzer properties are through

analyzer_dir = R3(x, y, z)
detector.setAnalyzer(analyzer_dir, efficiency, transmission)  # for scattering
scan.setAnalyzer(analyzer_dir, efficiency, transmission)  # for specular and offspec

The first argument is a unit vector that specifies the direction of the analyzer. The second argument is a number between 0 and 1 that specifies the analyzer efficiency. The third argument is a number between 0 and 0.5 that specifies the transmission of the analyzer for an unpolarized beam. The maximum value of $0.5$ corresponds to a perfect analyzer as half of an unpolarized incoming beam is not transmitted.

Examples are under Examples > Instrument > Polarization.

Examples to be moved: