DEVELOPMENT AND TESTING OF AN ADDITIVELY MANUFACTURED LATTICE FOR DEMO LIMITERS

DEVELOPMENT AND TESTING OF AN ADDITIVELY MANUFACTURED LATTICE FOR DEMO LIMITERS

DEVELOPMENT AND TESTING OF AN ADDITIVELY MANUFACTURED LATTICE FOR DEMO LIMITERS 150 150 UKAEA Opendata
UKAEA-CCFE-CP(22)02

DEVELOPMENT AND TESTING OF AN ADDITIVELY MANUFACTURED LATTICE FOR DEMO LIMITERS

In the conceptual design of EU-DEMO, damage to plasma facing components under disruption events is planned to be mitigated by specific sacrificial limiter components. A new limiter concept has been proposed using lattice structures fabricated with tungsten powder by additive manufacturing techniques. The major potential benefits of using a lattice structure for limiters are the possibility to customise the thermal conductivity and structural compliance of the structure in order to manage temperatures and stress within material limits and lower sensitivity to crack propagation. This paper presents the results of the first investigations into the production, characterisation and high heat flux testing of the lattices to assess their suitability for DEMO limiters. First stage prototypes have been manufactured from Tungsten and Tungsten Tantalum mixed powder with two distinct Laser Power Bed Fusion processes, namely pulsed laser and continuous laser with heated bed. The samples are characterised in term of mass, volume, density, extent of microcrack and voids, level of un-melted or partially melted particulate, texture and grain size, as well as Tantalum segregation when applicable. High transient (0.25ms) heat load testing, with plasma of energy density up to ~2 MJm-2 was carried out at QSPA. These tests have shown that the energy absorbed by latticed targets preheated at 500°C is close to that absorbed by solid tungsten (below the evaporation threshold). Mic. Performance of samples at steady state heat load environment has been assessed at the UKAEA HIVE facility with heat flux up to 3 MW/m2. Temperature distribution histories measured using infrared camera are presented.

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Conference:
28th IAEA Fusion Energy Conference, Nice, France, 10-15th May 2021
Published date:
26/01/2022