Embodiments that are directed to a target for producing a high epithermal neutron yield for boron-neutron capture therapy (BNCT) treatments are disclosed. The target includes a thin flat film of solid lithium mounted onto a heat-removal support structure that is cooled with a liquid coolant and configured to maintain the turbulent flow regime for a liquid coolant and distribute the flow of coolant directed at the center of the support structure toward a periphery of the support structure via a plurality of channels formed in the support structure. The support structure includes a nozzle located at its center to direct coolant flow outwardly from the center to avoid stagnant water flow at the center of the support structure. Systems, device, and methods utilizing the approaches are also described.