Do absorber fluctuations reduce interference in neutron interferometry?

A theory of joint nonideal measurement of incompatible observables is used to analyse absorber fluctuations in neutron interferometry. The theory is applied to two different fluctuation models. Also the influence of detector efficiency is discussed. Outcomes of the analysis are compared with conclusions based on the visibility of the interference pattern measured by one neutron detector only. It is demonstrated that the theory of joint measurement yields additional information on neutron interference experiments, thus making it a useful tool for analysing such experiments.