Commissioning and First Results of the OLMAT facility

Abstract

The OLMAT (Optimization of Liquid Metal Advanced Targets) facility has recently

undergone the commissioning and start-up phases. Solid Titanium-Zirconium- Molybdenum

(TZM) alloy and liquid tin (Sn) metallic targets were exposed to a hydrogen neutral beam

injector (NBI) particle flux with power densities up to 58 ±14 MW/m2, pulse duration up to

150 ms, and repetition rates up to 2 pulses/minute. These beam parameters are well above the

estimates based on the typical performance of this NBI system when used for heating plasmas

in the TJ-II stellarator. The parameters of the plasma generated through the interaction of the

fast (32.5 keV) neutrals and ions and the solid were characterized by spectroscopic methods

while surface temperature and total absorbed power were followed using pyrometry, infrared

(IR) thermography, and calorimetry, respectively. Targets were visually monitored during the

exposure and microscopically analyzed ex-situ. Electrical isolation of the target permitted

recording the floating voltage during irradiation as well as for active biasing tests. In this

work, a description of the facility, its operating parameters, and firsts results are provided and

assessed as a new High Heat Flux (HHF) Facility for testing solid and liquid metal divertor

targets under reactor-relevant heat load condition