The Extended Q-range Small-angle Neutron Scattering Diffractometer (EQ-SANS) instrument
at the spallation neutron source (SNS), Oak Ridge, Tennessee, incorporates a 69 m3 detector vessel with a vacuum system which required an upgrade with respect to performance,
ease of operation, and maintenance. The upgrade focused on improving pumping performance
as well as optimizing system design to minimize opportunity for operational error.
This upgrade provided the following practical contributions:•Reduced time required to evacuate from atmospheric pressure to 2 mTorr from 500 to
1000 min to 60–70 min•Provided turn-key automated control with a multi-faceted interlock for personnel and