Upgrade of the small-angle neutron scattering diffractometer SANS-J at JRR-3

The small-angle neutron scattering diffractometer SANS-J at the research reactor JRR-3, Tokai, Japan has been upgraded. A ³He front detector was installed adjacent to the direct beam just behind the sample position to cover scattering in the range 1.3–6 nm⁻¹ for the magnitude of the scattering vector Q. Additionally, the maximum Q covered by the existing main ³He detector was extended to 1.8 nm⁻¹ by decreasing the minimum sample-to-detector distance. These modifications enabled gapless measurements of the scattering curve in the Q range 0.002–6 nm⁻¹ with three standard device layouts that can be changed within 10 min. A new graphical user interface simplifies the operation of the device layouts and data acquisition.