AbstractThe flowing liquid surface retention experiment (FLIRE) has been designed to provide fundamental data on the retention and pumping of He, H and other species in flowing liquid surfaces. The FLIRE concept uses an ion source with current densities near 0.5 mA/cm2 and a working distance of 30–40 mm. The ion source injects 300–5000 eV ions into a flowing stream of liquid lithium at nearly normal incidence. FLIRE is a dual chamber unit. The liquid lithium flows into one vacuum chamber isolating it from a bottom vacuum chamber. Two residual gas analyzers with a quadrupole mass spectrometer, monitor the partial pressure of the implanted species in each vacuum chamber measuring retention and diffusion coefficients. A liquid–metal (LM) injection system experiment has been carried out to verify the capability of transporting liquid lithium. Results show that liquid metal velocities of the order of 1 m/s can be achieved. Safety tests conclude that exposing 300 °C lithium to atmosphere result in benign chemical reactions. A test of the external and internal heating systems conclude that LM transfer lines can be heated to temperatures near 270 °C and ramp temperatures near 400 °C.