Phase space effects on fast ion distribution function modeling in tokamaks
Here, integrated simulations of tokamak discharges typically rely on classical physics to model energetic particle (EP) dynamics. However, there are numerous cases in which energetic particles can suffer additional transport that is not classical in nature. Examples include transport by applied 3D magnetic perturbations and, more notably, by plasma instabilities. Focusing on the effects of instabilities,adhocmodels can empirically reproduce increased transport, but the choice of transport coefficients is usually somehow arbitrary. New approaches based on physicsbased reduced models are being developed to address those issues in a simplified way, while retaining a more correct treatment of resonant waveparticle interactions. The kick model implemented in the tokamaktransport code TRANSP is an example of such reduced models. It includes modifications of the EP distribution by instabilities in real and velocity space, retaining correlations between transport in energy and space typical of resonant EP transport. The relevance of EP phase space modifications by instabilities is first discussed in terms of predicted fast ion distribution. Results are compared with those from a simple, adhoc diffusive model. It is then shown that the phasespace resolved model can also provide additional insight into important issues such as internal consistency of the simulations and mode stability throughmore »
 Authors:

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 Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
 Publication Date:
 Report Number(s):
 PPPL5218
Journal ID: ISSN 1070664X; PHPAEN
 Grant/Contract Number:
 AC0209CH11466
 Type:
 Accepted Manuscript
 Journal Name:
 Physics of Plasmas
 Additional Journal Information:
 Journal Volume: 23; Journal Issue: 5; Related Information: The digital data for this paper can be found in http://arks.princeton.edu.ezproxy.princeton.edu/ark:/88435/dsp018p58pg29; Journal ID: ISSN 1070664X
 Publisher:
 American Institute of Physics (AIP)
 Research Org:
 Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
 Sponsoring Org:
 USDOE
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; magnetohydrodynamics; tokamaks, NSTX; transport phenomena; wave interaction; particles; phase space methods; particle distribution functions; neutrons; instability analysis; plasma transport properties
 OSTI Identifier:
 1254686
Podesta, M., Gorelenkova, M., Fredrickson, E. D., Gorelenkov, N. N., and White, R. B.. Phase space effects on fast ion distribution function modeling in tokamaks. United States: N. p.,
Web. doi:10.1063/1.4946027.
Podesta, M., Gorelenkova, M., Fredrickson, E. D., Gorelenkov, N. N., & White, R. B.. Phase space effects on fast ion distribution function modeling in tokamaks. United States. doi:10.1063/1.4946027.
Podesta, M., Gorelenkova, M., Fredrickson, E. D., Gorelenkov, N. N., and White, R. B.. 2016.
"Phase space effects on fast ion distribution function modeling in tokamaks". United States.
doi:10.1063/1.4946027. https://www.osti.gov/servlets/purl/1254686.
@article{osti_1254686,
title = {Phase space effects on fast ion distribution function modeling in tokamaks},
author = {Podesta, M. and Gorelenkova, M. and Fredrickson, E. D. and Gorelenkov, N. N. and White, R. B.},
abstractNote = {Here, integrated simulations of tokamak discharges typically rely on classical physics to model energetic particle (EP) dynamics. However, there are numerous cases in which energetic particles can suffer additional transport that is not classical in nature. Examples include transport by applied 3D magnetic perturbations and, more notably, by plasma instabilities. Focusing on the effects of instabilities,adhocmodels can empirically reproduce increased transport, but the choice of transport coefficients is usually somehow arbitrary. New approaches based on physicsbased reduced models are being developed to address those issues in a simplified way, while retaining a more correct treatment of resonant waveparticle interactions. The kick model implemented in the tokamaktransport code TRANSP is an example of such reduced models. It includes modifications of the EP distribution by instabilities in real and velocity space, retaining correlations between transport in energy and space typical of resonant EP transport. The relevance of EP phase space modifications by instabilities is first discussed in terms of predicted fast ion distribution. Results are compared with those from a simple, adhoc diffusive model. It is then shown that the phasespace resolved model can also provide additional insight into important issues such as internal consistency of the simulations and mode stability through the analysis of the power exchanged between energetic particles and the instabilities.},
doi = {10.1063/1.4946027},
journal = {Physics of Plasmas},
number = 5,
volume = 23,
place = {United States},
year = {2016},
month = {4}
}