Design and performance analyses of the new time-of-flight smaller-angle neutron scattering instrument at J-PARC

The new time-of-flight smaller-angle neutron scattering (TOF-SANS) instrument HI-SANS is projected to be built in the Materials and Life Science Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). The target of the HI-SANS is to study microstructures and hierarchical structures of nano-meter sized materials and their complexes. For the simultaneous collection of scattering data in the wide q range (∼3×10−3<q<∼50 Å−1) with good q-resolution and high efficiency, this instrument is designed to use large area detectors and broad wavelength bandwidth within the first frame. For the high-quality beam transport and the efficacious utilization of pulsed neutrons, the state of the art neutron optics is installed. Moreover, a focusing device based on sextupole magnets is adopted in the TOF-SANS for the first time to make accessible minimum q value (qmin) lower with high q resolution. The design optimization and performance analyses of the HI-SANS have been performed by Monte Carlo simulations.