Experimental set-up and process program for three-dimensional time-dependent neutron depolarization measurements

Abstract

The three-dimensional neutron depolarization technique makes use of the possibility to adjust the polarization direction of a thermal neutron beam in three orthogonal directions and to analyse the neutron beam in three orthogonal polarization directions after transmission through and depolarization by a specimen. The time dependence in the neutron depolarization technique is realized by applying a periodically changing magnetic field on the sample investigated and measuring the neutron intensity in time channels which are started synchronously with the external field. The experimental set-up for measurements with a time resolution of 8 μs, the details of the computer-controlled electronic system for the creation of the magnetic field and the time coding of the detected neutrons are discussed. The process program is presented by means of a current scheme and a functional description of the subroutines. Applications of the time dependent neutron depolarization technique are mentioned.