Validation and testing of high heat flux in-vessel components of the Material Plasma Exposure eXperiment (MPEX)

The Material Plasma Exposure eXperiment (MPEX) is a new linear plasma facility under construction at Oak Ridge National Laboratory to study reactor relevant plasma material interactions, novel plasma facing materials and neutron-irradiated samples under steady-state conditions. MPEX will be capable of operating steady-state (~ 2 weeks) with ~1 MW input power, thus in-vessel components require active cooling and monitoring. These in-vessel components include the microwave absorbers (MWA) used to absorber stray microwaves; tungsten limiters to form the outer boundary of the plasma column; an upstream dump (UD) that intercepts helicon plasma; and the target assembly located downstream from the helicon and RF heating regions of MPEX where plasma-material interaction (PMI) science will be performed with multiple plasma diagnostics such as spectroscopy and Thomson Scattering. Test articles of each of these in-vessel components have been designed and fabricated to closely match the MPEX design. The test articles are subject to MPEX relevant heat fluxes using an electron-beam to provide high heat fluxes (HHF) to the test article to validate the performance of thermal interfaces in each component. In the case of brazed thermal interfaces, ultrasonic testing (UT) has been used pre and post HHF testing to quantify the quality of the interface. HHF testing of the test articles is underway and results will be presented.