The bandwidth chopper system design of the energy-resolved neutron imaging instrument at CSNS

Abstract An imaging beam line, Energy-Resolved Neutron Imaging instrument (ERNI) is under construction at China Spallation Neutron Source (CSNS). Here we describe the design of its bandwidth chopper system, such as the operation modes and the determination of the chopper parameters by theoretical calculations. The Monte Carlo simulations using McStas are performed to check the design of the bandwidth choppers system. The results of the theoretical calculations and the Monte Carlo simulations agree well in this work.