Impact of wall conditions on impurity sourcing and core pollution during high fluence experiment and standard ohmic pulses in WEST

W erosion/redeposition of the Plasma-Facing Components (PFCs) and the resulting pollution of the plasma will be a major challenge for next step devices, such as ITER and SPARC. WEST’s unique characteristics with tungsten (W) PFCs offer an ideal platform to study plasma operations and plasma scenario development for long-pulsed, actively cooled, full W-PFC tokamaks [1]. Both impurity sources and resulting pollution are strongly dependent on the wall conditions as shown in previous WEST studies on 6 identical pulses reproduced across multiple campaigns from 2024 to 2025 [2]. The study has been carried out on a wider database set, during the high fluence campaign (2023) and for the standard ohmic pulses performed daily in the 2025 campaign. The cumulative energy from last glow discharge boronization (E_cum) is used as a metric to assess the wall conditions impact on impurity sourcing and core pollution parameters: impurity sources (i.e., B, C, N, O, W fluxes), radiated power, central electron temperature (T_ECE) and the W concentration estimation in the confined plasma (n_W). First results show that C fluxes at the divertor targets becomes equivalent to B fluxes around E_cum = 8 GJ_, while O remains minority during the whole study. T_ECE and n_W do not demonstrate a clear correlation to the upper and lower divertor impurity sources evolution with E_cum.