A major challenge facing the steady-state operation of tokamak fusion reactors is to develop a viable divertor solution with order-of-magnitude increase in power handling capability as compared with present experience...A major challenge facing the steady-state operation of tokamak fusion reactors is to develop a viable divertor solution with order-of-magnitude increase in power handling capability as compared with present experience.A recently developed divertor concept for this end has been tested recently on EAST tokamak through combining the effects of a closed divertor corner and E×B drifts.The E×B drifts in the divertor move particles towards the outer divertor corner area in the scrape-off layer for B×▽B directed away from the divertor,which can significantly enhance the particle concentration there,facilitating divertor detachment.In recent EAST experiments,the effects have been demonstrated where the lowest electron temperature at the divertor plate is obtained with strike point located close to the corner in the horizontal target and with B×▽B away from the divertor.These experimental results are in reasonable agreement with SOLPS-ITER simulations including drift effects,suggesting that the new divertor concept potentially provides a promising divertor solution for long-pulse operations of future tokamak fusion reactors with much higher power fluxes.展开更多
A series of L-mode discharges have been conducted in the new‘corner slot’divertor on the Experimental Advanced Superconducting Tokamak(EAST)to study the divertor plasma behavior through sweeping strike point.The pla...A series of L-mode discharges have been conducted in the new‘corner slot’divertor on the Experimental Advanced Superconducting Tokamak(EAST)to study the divertor plasma behavior through sweeping strike point.The plasma control system controls the strike point sweeping from the horizontal target to the vertical target through poloidal field coils,with keeping the main plasma stability.The surface temperature of the divertor target cools down as the strike point moves away,indicating that sweeping strike point mitigates the heat load.To avoid the negative effect of probe tip damage,a method based on sweeping strike point is used to get the normalized profile and study the decay length of particle and heat flux on the divertor target λ_(js),_λ(q).In the discharges with high radio-frequency(RF)heating power,electron temperature T_(e) is lower and λ_(js)is larger when the strike point locates on the horizontal target compared to the vertical target,probably due to the corner effect.In the Ohmic discharges,λ_(js),λ_(q) are much larger compared to the discharges with high RF heating power,which may be attributed to lower edge T_(e).展开更多
基金funded by the National Magnetic Confinement Fusion Program of China(Nos.2019YFE03030000,2019YFE03080500 and 2022YFE03060004)National Natural Science Foundation of China(No.U19A20113)。
文摘A major challenge facing the steady-state operation of tokamak fusion reactors is to develop a viable divertor solution with order-of-magnitude increase in power handling capability as compared with present experience.A recently developed divertor concept for this end has been tested recently on EAST tokamak through combining the effects of a closed divertor corner and E×B drifts.The E×B drifts in the divertor move particles towards the outer divertor corner area in the scrape-off layer for B×▽B directed away from the divertor,which can significantly enhance the particle concentration there,facilitating divertor detachment.In recent EAST experiments,the effects have been demonstrated where the lowest electron temperature at the divertor plate is obtained with strike point located close to the corner in the horizontal target and with B×▽B away from the divertor.These experimental results are in reasonable agreement with SOLPS-ITER simulations including drift effects,suggesting that the new divertor concept potentially provides a promising divertor solution for long-pulse operations of future tokamak fusion reactors with much higher power fluxes.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFE0301300)the National Natural Science Foundation of China(Grant Nos.12005257,12005004,11905143,and 11922513)+3 种基金the Fund from the Institute of Energy,Hefei Comprehensive National Science Center(Grant No.GXXT-2020-004)the CASHIPS Director’s Fund(Grant Nos.BJPY2019A01 and YZJJ2020QN13)the Special Research Assistant Funding of CAS and China Postdoctoral Science Foundation(Grant No.2020M671913)Anhui Provincial Natural Science Foundation(Grant No.2008085QA38)。
文摘A series of L-mode discharges have been conducted in the new‘corner slot’divertor on the Experimental Advanced Superconducting Tokamak(EAST)to study the divertor plasma behavior through sweeping strike point.The plasma control system controls the strike point sweeping from the horizontal target to the vertical target through poloidal field coils,with keeping the main plasma stability.The surface temperature of the divertor target cools down as the strike point moves away,indicating that sweeping strike point mitigates the heat load.To avoid the negative effect of probe tip damage,a method based on sweeping strike point is used to get the normalized profile and study the decay length of particle and heat flux on the divertor target λ_(js),_λ(q).In the discharges with high radio-frequency(RF)heating power,electron temperature T_(e) is lower and λ_(js)is larger when the strike point locates on the horizontal target compared to the vertical target,probably due to the corner effect.In the Ohmic discharges,λ_(js),λ_(q) are much larger compared to the discharges with high RF heating power,which may be attributed to lower edge T_(e).
