ИСТИНА

A new neutron spin-echo method based on the use of time-gradient magnetic field has recently been proposed. This method is one of the variants of neutron spin-echo technique that is applied to pulsed neutron source such as being built now at ESS in Lund. SESANS instrument that applicate such technique is being developed in Dubna at the IBR-2 at the present time. This study presents the operational modes of a virtual SESANS instrument built by using the simulation package VITESS with parameters of developing machine. In addition, the issue of resolution improving applying scattered beam collimation was considered. The sectoral and rectangular collimators in the SESANS method with time-gradient magnetic fields are considered by means of Monte-Carlo simulations in VITESS package. It is shown, that the use of a sectoral collimator improves resolution and time of measurement in spite of the excluded part of scattered neutrons.