@article{article,
  author = {A. Panera Alvarez and F. Kochl and J. Artaud and E. Geulin and B. Pegourie and E. Vergnaud and C. Bourdelle and S. Wiesen},
  title = {Integrated full pulse modeling for pellet injection in tokamaks: HPI2 model improvement and validation in WEST},
  abstract = {Reliable modeling and control of core density is essential for reactor-relevant magnetic confinement fusion operation, motivating cryogenic pellet injection as a primary fueling actuator and the need for predictive pellet source models in integrated modeling. Here we present an upgrade of the physics-based pellet code HPI2 in which the plasmoid release spatial step is determined self-consistently from ablation physics, dx var = v pel t exit (optionally rescaled to trade accuracy for computational cost), removing an ad-hoc discretization parameter and improving numerical robustness across injection conditions. The upgraded model is first validated in stand-alone against a high-field-side pellet-fueled, ohmic, WEST discharge ($\#$58656) by comparing synthetic and measured interferometry line-integrated density increments, obtaining a mean error of ∽10\%. We then perform full-radius, time-dependent integrated modeling validation by coupling the new HPI2 within the High Fidelity Pulse Simulator (HFPS) workflow (JINTRAC/IMAS), combining JETTO with SANCO for the impurity/radiation evolution and TGLF-SAT2 for the turbulent transport. The coupled simulations reproduce the main density rise and relaxation after pellet injection and the associated electron-temperature transient, while taking into account the strong influence of tungsten radiation in WEST, supporting the consistency of HPI2 as a predictive pellet particle source in integrated modeling frameworks. Ultimately, this validation study supports the use of pellet modeling tools in integrated modeling studies for larger devices such as ITER.},
  year = {2026},
  journal = {Nuclear Fusion},
  volume = {66},
  pages = {in press},
  publisher = {IOP Publishing},
  doi = {10.1088/1741-4326/ae89cd},
  language = {eng},
}