Present status and prospects for Spin-Echo Small-Angle Neutron Scattering (SESANS) at PIK neutron source

Abstract

We discuss the present status and the prospects of Spin Echo Small Angle Neutron Scattering (SESANS) against the background of the available expertise and the neutron source PIK at PNPI (Gatchina). Two options for SESANS instruments are reviewed: (1) monochromatic with π flipping permalloy foils and (2) with adiabatic radio frequency spin flippers in a white beam, combined with time of flight data collec tion. A software tool for quantitative prediction of the technical properties of option (2) is developed. For both options, we show that a SESANS instrument which can compete with instruments elsewhere, is realistic. For option (2), we suggest a perspective of spin echo length range such that neutron interference experiments become feasible.

Algorithm of the Computer Modelling and a SESANS Setup with Adiabatic RF-Flippers

“…1b, c. We made MATLAB software [6] to simulate the Larmor precession in a NSE-arm made up of 2 such flippers and to calculate the coefficient Γ. We use the 4 identical electro-magnets existing at PNPI.…”