Prototype Spallation Neutron Source Rotating Target Assembly Final Test Report

A full-scale prototype of an extended vertical shaft, rotating target assembly based on a conceptual target design for a 1 to 3-MW spallation facility was built and tested. Key elements of the drive/coupling assembly implemented in the prototype include high integrity dynamic face seals, commercially available bearings, realistic manufacturing tolerances, effective monitoring and controls, and fail-safe shutdown features. A representative target disk suspended on a 3.5 meter prototypical shaft was coupled with the drive to complete the mechanical tests. Successful operation for 5400 hours confirmed the overall mechanical feasibility of the extended vertical shaft rotating target concept. The prototype system showed no indications of performance deterioration and the equipment did not require maintenance or relubrication.