U.S. Department of EnergyOffice of Scientific and Technical Information
To dee or not to dee: costs and benefits of altering the triangularity of a steady-state DEMO-like reactor
Abstract
Shaping a tokamak plasma to have a negative triangularity may allow operation in an ELM-free L-mode regime and with a larger strike-point radius, ameliorating divertor power-handling requirements. However, the shaping has a potential drawback in the form of a lower no-wall ideal beta limit, found using the MHD codes CHEASE and DCON. Using the new fusion systems code FAROES, we construct a steady-state DEMO2 reactor model. This model is essentially zero-dimensional and neglects variations in physical mechanisms like turbulence, confinement, and radiative power limits, which could have a substantial impact on the conclusions deduced herein. Keeping its shape otherwise constant, we alter the triangularity and compute the effects on the levelized cost of energy (LCOE). If the tokamak is limited to a fixed B field, then unless other means to increase performance (such as reduced turbulence, improved current drive efficiency or higher density operation) can be leveraged, a negative-triangularity reactor is strongly disfavored in the model due to lower \beta_N limits at negative triangularity, which leads to tripling of the LCOE. However, if the reactor is constrained by divertor heat fluxes and not by magnet engineering, then a negative-triangularity reactor with higher B0 could be favorable: we find a classmore »
- Authors:
-
- Princeton Plasma Physics Laboratory
- Publication Date:
- DOE Contract Number:
- AC02-09CH11466
- Research Org.:
- Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- Subject:
- CHEASE; DCON; FAROES; cost of electricity; fusion reactor economics; plasma; systems code; tokamak
- OSTI Identifier:
- 1888268
- DOI:
- https://doi.org/10.11578/1888268
Citation Formats
Schwartz, Jacob A, Nelson, A O, and Kolemen, Egemen. To dee or not to dee: costs and benefits of altering the triangularity of a steady-state DEMO-like reactor. United States: N. p., 2022.
Web. doi:10.11578/1888268.
Schwartz, Jacob A, Nelson, A O, & Kolemen, Egemen. To dee or not to dee: costs and benefits of altering the triangularity of a steady-state DEMO-like reactor. United States. doi:https://doi.org/10.11578/1888268
Schwartz, Jacob A, Nelson, A O, and Kolemen, Egemen. 2022.
"To dee or not to dee: costs and benefits of altering the triangularity of a steady-state DEMO-like reactor". United States. doi:https://doi.org/10.11578/1888268. https://www.osti.gov/servlets/purl/1888268. Pub date:Fri Apr 08 04:00:00 UTC 2022
@article{osti_1888268,
title = {To dee or not to dee: costs and benefits of altering the triangularity of a steady-state DEMO-like reactor},
author = {Schwartz, Jacob A and Nelson, A O and Kolemen, Egemen},
abstractNote = {Shaping a tokamak plasma to have a negative triangularity may allow operation in an ELM-free L-mode regime and with a larger strike-point radius, ameliorating divertor power-handling requirements. However, the shaping has a potential drawback in the form of a lower no-wall ideal beta limit, found using the MHD codes CHEASE and DCON. Using the new fusion systems code FAROES, we construct a steady-state DEMO2 reactor model. This model is essentially zero-dimensional and neglects variations in physical mechanisms like turbulence, confinement, and radiative power limits, which could have a substantial impact on the conclusions deduced herein. Keeping its shape otherwise constant, we alter the triangularity and compute the effects on the levelized cost of energy (LCOE). If the tokamak is limited to a fixed B field, then unless other means to increase performance (such as reduced turbulence, improved current drive efficiency or higher density operation) can be leveraged, a negative-triangularity reactor is strongly disfavored in the model due to lower \beta_N limits at negative triangularity, which leads to tripling of the LCOE. However, if the reactor is constrained by divertor heat fluxes and not by magnet engineering, then a negative-triangularity reactor with higher B0 could be favorable: we find a class of solutions at negative triangularity with lower peak heat flux and lower LCOE than those of the equivalent positive triangularity reactors.},
doi = {10.11578/1888268},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Apr 08 04:00:00 UTC 2022},
month = {Fri Apr 08 04:00:00 UTC 2022}
}