A model for the pedestal density prediction based on neutral penetration combined with pedestal transport is presented. The model is tested against a pedestal database of JET-ILW Type I ELMy H-modes showing good agreement over a wide range of parameters both in standalone modelling (using the experimental temperature profile) and in full Europed modelling that predicts both density and temperature pedestals simultaneously. The model is further tested for ASDEX Upgrade and MAST-U Type I ELMy H-modes and both are found to agree with the same model parameters as for JET-ILW. The JET-ILW experiment where the isotope of the main ion is varied in a D/T scan at constant gas rate and constant is successfully modelled as long as the separatrix density ( and pedestal transport coefficient ratio ( are varied in accordance with the experimentally observed variation of and the isotope dependence of found in gyrokinetic simulations. The predictions are found to be sensitive to which is why the model is combined with an model to predict the pedestal for the STEP fusion reactor.
Saarelma, S., Connor, J. W., Bílková, P., Bohm, P., Bowman, C., Field, A. R., Frassinetti, L., Friedström, R., Henderson, S., Imada, K., Kirk, A., Kwon, O. J., Luda, T., Sarwar, R., Scannell, R., & Smith, S. F. (2024). Density pedestal prediction model for tokamak plasmas. Nuclear Fusion, 64(7). https://doi.org/10.1088/1741-4326/ad4b3e
Saarelma, S., Connor, J. W., Bílková, P., et al., "Density pedestal prediction model for tokamak plasmas," Nuclear Fusion 64, no. 7 (2024), https://doi.org/10.1088/1741-4326/ad4b3e
@article{osti_2369756,
author = {Saarelma, S. and Connor, J. W. and Bílková, P. and Bohm, P. and Bowman, C. and Field, A. R. and Frassinetti, L. and Friedström, R. and Henderson, S. and Imada, K. and others},
title = {Density pedestal prediction model for tokamak plasmas},
annote = {Abstract A model for the pedestal density prediction based on neutral penetration combined with pedestal transport is presented. The model is tested against a pedestal database of JET-ILW Type I ELMy H-modes showing good agreement over a wide range of parameters both in standalone modelling (using the experimental temperature profile) and in full Europed modelling that predicts both density and temperature pedestals simultaneously. The model is further tested for ASDEX Upgrade and MAST-U Type I ELMy H-modes and both are found to agree with the same model parameters as for JET-ILW. The JET-ILW experiment where the isotope of the main ion is varied in a D/T scan at constant gas rate and constant β N is successfully modelled as long as the separatrix density ( n e,sep ) and pedestal transport coefficient ratio ( D / χ ) are varied in accordance with the experimentally observed variation of n e,sep and the isotope dependence of D / χ found in gyrokinetic simulations. The predictions are found to be sensitive to n e,sep which is why the model is combined with an n e,sep model to predict the pedestal for the STEP fusion reactor. },
doi = {10.1088/1741-4326/ad4b3e},
url = {https://www.osti.gov/biblio/2369756},
journal = {Nuclear Fusion},
issn = {ISSN 0029-5515},
number = {7},
volume = {64},
place = {IAEA},
publisher = {IOP Publishing},
year = {2024},
month = {06}}
Field, A. R.; Chapman-Oplopoiou, B.; Connor, J. W.
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 381, Issue 2242https://doi.org/10.1098/rsta.2021.0228