Polarization analysis with slow neutrons

The paper is the critical review of the present day status of polarization analysis with neutrons in the energy range from several tens neV (ultracold neutrons: UCN) to parts of eV (epithermal neutrons). A common description is given within the formalism of 2x2 Pauli matrices for the known schemes of polarization analysis, where the coherent effects may be neglected. The components of the schemes (so-called beam transformers-polarizer, spin-flipper and polarization analyser) are fully characterized with the four integral parameters. They are the beam yransformation coefficient, polarizing and analysing efficiencies and so-called S-factor describing the part of neutrons which conserved the direction of spin after interacting with the transformer. Experimental determination of the above parameters would have allowed one to restore 2x2 transformation matrix and thus to obtain information on the mechanism of neutron interaction with the transformer. Such a method has been proposed only for UCN up to now. It is based on the possibility of UCN storage and their pumping fromone storage volume into another. This allows one to use the transformer as s polarizer and analyser altogether. The method waits for its experimental test