Article

Computational Investigation of Beryllium and Lithium Performance in Future Fusion Tokamaks

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Elbasha, N. M., Bourham, M. A., & Mohamed, B. F. (2022). Computational Investigation of Beryllium and Lithium Performance in Future Fusion Tokamaks. New Energy Exploitation and Application, 1(1), 17–24. https://doi.org/10.54963/neea.v1i1.17

Authors

  • N. M. Elbasha
    Physics Department, Faculty of Science, Ain Shams University, Cairo, Egypt
  • M. A. Bourham North Carolina State University, Department of Nuclear Engineering, Raleigh, NC 27695, USA
  • B. F. Mohamed Plasma Physics Department, Nuclear Research Centre, Atomic Energy Authority, Cairo, Egypt

Low-z materials are exemplary candidates in tiling critical plasma-facing components in future fusion reactors due to their low ablation rates under intense high heat fluxes especially during abnormal and hard disruption events. Beryllium and Lithium as low-z materials show good performance as plasma-facing materials in current tokamak. Future tokamaks will exhibit long duration hard disruptions, which in turn requires further investigation of plasma-facing materials, as Li and Be, to judge their performance and evaluate their erosion rates. Electrothermal plasma capillary discharges are used to simulate the high-heat flux deposition on materials to assess their erosion rates. The electrothermal plasma code ETFLOW, which is written for capillary discharges to predict the plasma parameters and erosion rates is used to simulate the high-heat flux conditions similar to expected disruption events for simulated heat fluxes from as low as ~50 to as high as ~290 GW/m2 with a reconnoitering of generating the Be and Li plasmas up to the third ionization (Br+++, Li+++). Performance of Be and Li under the lowest capillary discharge currents (50 kA and 100 kA) is almost identical, however, Li shows sharper increase in the plasma pressure, heat flux, total ablated mass and the exit velocities than Be for higher discharge currents (150, 200 and 250 kA). This huge difference between the performance of Li and Be under low and high heat fluxes can be an important issue for the future magnetic fusion reactors.

Keywords:

Plasma facing materials Tokamak Hard disruptions The next fusion reactors The low-z materials

References

  1. Robert, W.C., Russell, P. Doerner, Jongik Won, 1997. Beryllium as the plasma-facing material in fusion energysystems—experiments, evaluation, and comparison with alternative materials, Fusion Engineering and Design. 37, 481-513.
  2. Asif, M., 2014. The HT-7 Team, Theoretical Calculation of Effective Ionic Charge with Lithium Limiter on HT-7 Tokamak, J Fusion Energ. 33, 444-448.
  3. Hassanein, A., Ehst., D.A., 1994. Beryllium and graphite performance in ITER during a disruption , Journal of Nuclear Materials. 212-215, 1272-1277.
  4. Federici, G., Skinner, C.H., Brooks, J.N., Coad, J.P., Grisolia, C., Haasz, A.A., Hassanein, A., Philipps, V.,Pitcher, C.S., Roth, J., et al., 2001. Plasma-material interactions in current tokamaks and their implications for next step fusion, reactors Nuclear Fusion. Vol. 41, No. 12R.
  5. Echols, J.R., Winfrey, A.L., 2014. Ablation of Fusion Materials Exposed to High Heat Flux in an Electrothermal Plasma Discharge as a Simulation for Hard Disruption, J Fusion Energ. 33, 60-67. DOI: https://doi.org/10.1007/s10894-013-9639-4.
  6. Barabash, V., Eaton, R., Hirai, T., Kupriyanov, I., Nikolaev, G., Wang, Zh.H., Liu, X., Roedig, M., Linke, J., 2011. Summary of beryllium qualification activity for ITER first-wall applications, Phys. Scr. T145, 014007.
  7. Snipes, J.A., 1992. Wall conditioning with impurity pellet injection on TFTR, Journa of nuclear materials. 196-198, 686-691.
  8. Majeski, R., Jardin, S., Kaita, R., Gray, T., Marfuta, P., Spaleta, J., Timberlake, J., Zakharov, L.E., Ghassan Antar, R., Doerner et al., 2005. Nucl. Fusion. 45, 519-523.
  9. Mirnov, S.V., Azizov, E.A., Evtikhin, V.A., Lazarev, V.B., Lyublinski, I.E., Vertkov, A.V., Yu Prokhorov,D., 2006. Plasma Phys. Control. Fusion 48, 821.
  10. Apicella, M.L., Lazarev, V., Lyublinski, I., Mazzitelli, G., Mirnov, S., Vertkov, A., 2009. Lithium capillary porous system behavior as PFM in FTU tokamak experiments. Journal of Nuclear Materials. 386-388, 821-823.
  11. Evtikhin, V.A., Lyublinski, I.E., Vertkov, A.V., Azizov, E.A., Mirnov, S.V., Lazarev, V.B., Sotnikov, S.M., Safronov, V.M., Prokhorov, A.S., Korzhavin, V.M., June 2004. Main Directions and Recent Test Modeling Results of Lithium Capillary-Pore Systems as Plasma Facing Components, Plasma Science & Technology. vo1.6, No.3.
  12. Hu, J.S., Zuo, G.Z., Li, J.G., Luo, N.C., Zakharov, L.E., Zhang, L., Zhang, W., Xu, P., 2010. Investigation of lithium as plasma facing materials on HT-7, J.S. Hu et al. / Fusion Engineering and Design. 85, 930-934.
  13. Ruzic, D.N., Shaheen, M., 1992. Wall conditioning with impurity pellet on TFTR, Journal of nuclear materials. 196-198, 686-691.
  14. Spitzer, L., Härm, R., Mar. 1953. Transport phenomena in a completely ionized gas. Phys. Rev. 89(5),971-981.
  15. Zaghloul, M.R., Bourham, M.A., Doster, J.M., Powell, J.D., October 1999. On the Average Electron-Ion Momentum Transport Cross-Section in Ideal and Nonideal Plasmas. Physics Letters A. Vol. 262/1, pp. 86-89.
  16. Zaghloul, M.R., Bourham, M.A., Doster, J.M., April 2000. Energy-Averaged Electron-Ion Momentum Transport Cross-Section in the Born Approximation and Debye-Huckel Potential: Comparison with the Cut-Off Theory. Physics Letters A. Vol. 268/4-6, pp.375-381.
  17. Vergara, P.P., Gilligan, J., Winfrey, L., Bourham, M., 2015. Generalized Scaling Laws of Plasma Parameters in Electrothermal Plasma Sources for Fusion Disruption Erosion and Hypervelocity Launch Applications, IEEE Trans Plasma Sc. 43(10), 3645-3652 .
  18. Terry, J.L., Marmar, E.S., Howell, R.B., 1990. Measurement of internal magnetic field pitch using Li pellet injection on TFTR (invited), Review of Scientific Instruments. 61, 2908. DOI: https://doi.org/10.1063/1.1141775.