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Divertor detachment is a critical technique for managing the thermal load on the divertor of the HL-3 tokamak, a key device in magnetic confinement fusion research. However, existing studies on detachment have largely overlooked the complex multi-species particle dynamics in the scrape-off layer (SOL) and divertor regions, particularly the interactions involving hydrogen isotopes (e.g., deuterium), externally injected impurities (e.g., neon), and intrinsic impurities (e.g., carbon). This study aims to address this gap by employing the newly developed multi-species particle transport code SD1D to investigate the effects of carbon impurities and neutral particles on two detachment scenarios in HL-3: plasma density ramp-up and neon injection into the divertor.
The SD1D code models the transport, collision, and radiation processes of various particles, including deuterium ions, atoms, and molecules, as well as carbon and neon impurities, along the magnetic field lines from the SOL upstream to the divertor target. The study focuses on understanding how carbon impurities and neutral particles influence the detachment mechanisms under different conditions.
The results reveal that carbon impurities generated in the divertor significantly enhance detachment in the density ramp-up scenario by increasing the density of deuterium atoms, molecules, and ions near the target plate, thereby boosting the total radiation power. This effect lowers the density threshold required for detachment and reduces the peak current on the target plate. However, carbon impurities have a minimal impact on detachment achieved through neon injection, as they do not significantly alter the density of deuterium species or the total radiation power in this scenario.
Furthermore, the study highlights the distinct roles of neutral particles in the two detachment mechanisms. In the density ramp-up scenario, the increased plasma density promotes the recycling process in the divertor, generating a substantial population of neutral particles. The energy and momentum losses resulting from plasma-neutral interactions are crucial for achieving detachment. In contrast, neon injection directly reduces the saturation current on the target plate, suppressing the recycling process and diminishing the importance of neutral particles.
In conclusion, this work demonstrates that carbon impurities play a significant role in facilitating detachment during plasma density ramp-up but have limited influence on detachment via neon injection. The findings underscore the importance of considering multi-species particle dynamics, including neutral particles and impurities, in understanding and optimizing divertor detachment strategies. Future work will involve validating the SD1D model against experimental data from HL-3 to further refine its predictive capabilities.-
Keywords:
- Divertor detachment /
- HL-3 tokamak /
- neutral particles /
- carbon impurities
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[1] Stangeby, Peter C. The plasma boundary of magnetic fusion devices. CRC Press, 2000.
[2] Kallenbach, A., Bernert, M., Dux, R., Reimold, F., Wischmeier, M., & ASDEX Upgrade Team. 2016. Plasma Physics and Controlled Fusion, 58(4), 045013.
[3] Stangeby P C 2018. Plasma Physics and Controlled Fusion, 60(4):044022
[4] Verhaegh, K., Lipschultz, B., Bowman, C., Duval, B.P., Fantz, U., Fil, A., Harrison, J.R., Moulton, D., Myatra, O., Wünderlich, D. and Federici, F., 2021. Plasma Physics and Controlled Fusion, 63(3), p.035018.
[5] Kunze, H.J., 2009. 56, Springer Science & Business Media.
[6] Bernert, M., Wischmeier, M., Huber, A., Reimold, F., Lipschultz, B., Lowry, C., Brezinsek, S., Dux, R., Eich, T., Kallenbach, A. and Lebschy, A., 2017.Nuclear Materials and Energy, 12, pp.111-118.
[7] Ting, W.U., Lin, N.I.E., Yi, Y.U., Jinming, G.A.O., Junyan, L.I., Huicong, M.A., Jie, W.E.N., Rui, K.E., Na, W.U., Huang, Z. and Liang, L.I.U., 2022. Plasma Science and Technology, 25(1), p.015102.
[8] Zhou, Y., Dudson, B., Militello, F., Verhaegh, K. and Myatra, O., 2022. Plasma Physics and Controlled Fusion, 64(6), p.065006.
[9] Boedo, J., Gray, D., Chousal, L., Conn, R., Hiller, B. and Finken, K.H., 1998. Review of scientific instruments, 69(7), pp.2663-2670.
[10] Boedo J A, Crocker N, Chousal L, Hernandez R, Chalfant J, Kugel H, Roney P, Wertenbaker J and NSTX Team 2009. Review of Scientific Instruments, 80(12):123506
[11] Clark, J.G., Bowden, M.D. and Scannell, R., 2021. Low temperature. Review of Scientific Instruments, 92(4).
[12] Makarov, S.O., Coster, D.P., Kaveeva, E.G., Rozhansky, V.A., Senichenkov, I.Y., Veselova, I.Y., Voskoboynikov, S.P., Stepanenko, A.A., Bonnin, X. and Pitts, R.A., 2023. Nuclear Fusion, 63(2), p.026014.
[13] Mailloux, J., Abid, N., Abraham, K., Abreu, P., Adabonyan, O., Adrich, P., Afanasev, V., Afzal, M., Ahlgren, T., Aho-Mantila, L. and Aiba, N., 2022. Nuclear Fusion, 62(4), p.042026.
[14] Fil, A., Lipschultz, B., Moulton, D., Thornton, A., Dudson, B.D., Myatra, O., Verhaegh, K. and EUROfusion MST1 Team, 2022. Nuclear Fusion, 62(9), p.096026.
[15] Myatra, O., Moulton, D., Dudson, B., Lipschultz, B., Newton, S., Verhaegh, K. and Fil, A., 2023. Nuclear Fusion, 63(7), p.076030.
[16] Verhaegh, K., Lipschultz, B., Duval, B.P., Harrison, J.R., Reimerdes, H., Theiler, C., Labit, B., Maurizio, R., Marini, C., Nespoli, F. and Sheikh, U., 2017. Nuclear Materials and Energy, 12, pp.1112-1117.
[17] Gao, J.M., Cai, L.Z., Cao, C.Z., Ma, H.C., Ke, R., Wu, N., Hu, Y., Gao, X.Y., Cui, C.H., Huang, Z.H. and Nie, L., 2023. Nuclear Fusion, 63(3), p.036006.
[18] Long T, Ke R, Wu T, Gao J M, Cai L Z, Wang Z H, Xu M, 2024. Acta Phys. Sin., 73(8): 088901 [龙婷, 柯锐, 吴婷, 高金明, 才来中, 王占辉, 许敏, 2024. 73(8): 088901]
[19] Wu, N., Cheng, J., Yi, K.Y., Wang, R., Han, M.K., Huang, Z.H., Wang, W.C., He, Y., Yan, L.W., Du, H.L. and Gao, J.M., 2024. Nuclear Fusion, 64(9), p.096007.
[20] Liu, J.B., Wang, L., Guo, H.Y., Wang, H.Q., Xu, G.S., Ding, F., Xu, J.C., Liu, X.J., Yuan, Q.P., Wu, K. and Liu, S.C., 2019. Nuclear Fusion, 59(12), p.126046.
[21] Dudson, B.D., Allen, J., Body, T., Chapman, B., Lau, C., Townley, L., Moulton, D., Harrison, J. and Lipschultz, B., 2019. Plasma Physics and Controlled Fusion, 61(6), p.065008.
[22] Kallenbach, A., Bernert, M., Dux, R., Eich, T., Henderson, S.S., Pütterich, T., Reimold, F., Rohde, V., Sun, H.J. and ASDEX Upgrade Team, 2019.Nuclear Materials and Energy, 18, pp.166-174.
[23] Zhou, Y., Dudson, B., Wu, T., Wang, Z., Xia, T., Zhong, C., Gao, J., Du, H. and Fan, D., 2024. Plasma Physics and Controlled Fusion, 66(5), p.055005.
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