A Design Study of a Compact Small-Angle Neutron Scattering Instrument

Abstract: Nanoscale structure determination belongs to one of the crucial tasks in materials science. Small-angle neutron scattering (SANS) is a highly valuable tool to investigate nanostructures. Here, we explore the possibility of a compact SANS instrument to be installed at an individual accelerator based pulsed low-flux source, and discuss applications in structural characterization, education, and training. Monte Carlo simulations of a realistic setup demonstrate the feasibility of such an instrument, with an ideal measurement taking about 7 hours. The anticipated length-scale measurement range is 0.5 nm to 50 nm. The minimalistic design results in an easy to operate, low maintenance instrument, independent of the schedules of large-scale facilities. Size, cost, and maintenance are comparable to laboratory small-angle X-ray scattering (SAXS) instruments, which makes SANS affordable for individual research teams at universities and provides unique chances for education and training. The proposed setup creates the opportunity to measure ultraslow structural changes, at a fraction of the cost of existing SANS instruments, hence enables weekly or monthly repetition rates. The concept can be expanded to an entire suite of instruments, including wide-angle neutron scattering (WANS) and diffraction, neutron reflectometry (NR), neutron radiography, grating interferometry (GI), and prompt gamma activation analysis (PGAA).