Commissioning phase of high heat flux test facility HELCZA

The high heat flux test facility HELCZA (High Energy Load CZech Assembly) is in the commissioning phase in which the full range of operational parameters of the facility are being validated. HELCZA is designed for cyclic heat loading for testing ITER plasma-facing components with heat flux densities in the range of several MW/m2. The heat flux is ensured by an 800 kW electron beam gun emitting electrons at 55 kV acceleration voltage. The main parameters to be validated concern not only the maximum power of the electron beam but also the entire cooling system which enables to vary the inlet cooling water temperature in a range from room temperature up to 320 °C and water pressure up to 15 MPa. The design flow rate is adjustable up to 40 m3/h over the entire temperature and pressure range. The sample movement is ensured by three types of sample holders for: a) First Wall panels, b) divertor inner vertical target and c) antenna faraday screens as well as other test mock-ups and small-scale samples. All the above mentioned system parameters are currently being tested with the objective of a full validation of HELCZA facility during its commissioning phase, which is currently proceeding. The first part of the commissioning phase results are shown and described in detail.