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Polevoi, A. R.*; Loarte, A.*; 林 伸彦; Kim, H. S.*; Kim, S. H.*; Koechl, F.*; Kukushkin, A. S.*; Leonov, V. M.*; Medvedev, S. Yu.*; 村上 匡且*; et al.
Nuclear Fusion, 55(6), p.063019_1 - 063019_8, 2015/05
被引用回数：33 パーセンタイル：84.89(Physics, Fluids & Plasmas)The operational space (
-
) for long pulse scenarios of ITER was assessed by 1.5D core transport modelling with pedestal parameters predicted by the EPED1 code. The analyses include the majority of transport models presently used for interpretation of experiments and ITER predictions. The EPED1 code was modified to take into account boundary conditions predicted by SOLPS for ITER. In contrast with standard EPED1 assumptions, EPED1 with the SOLPS boundary conditions predicts no degradation of the pedestal pressure as density is reduced. Lowering the plasma density to 
5-6 
10
m
leads to an increased plasma temperature (similar pedestal pressure), which reduces the loop voltage and increases the duration of the burn phase to 
1000 s with Q 
5 for 
13 MA at moderate normalised pressure (
2). These ITER plasmas require the same level of additional heating power as the reference Q = 10 inductive scenario at 15 MA. However, unlike the "hybrid" scenarios considered previously, these H-mode plasmas do not require specially shaped q profiles nor improved confinement in the core for the transport models considered in this study. Thus, these medium density H-mode plasma scenarios with 13 MA present an attractive alternative to hybrid scenarios to achieve ITER's long pulse Q 5 and deserve further analysis and experimental demonstration in present tokamaks.
Polevoi, A. R.*; 林 伸彦; Kim, H. S.*; Kim, S. H.*; Koechl, F.*; Kukushkin, A. S.*; Leonov, V. M.*; Loarte, A.*; Medvedev, S. Yu.*; 村上 匡且*; et al.
Europhysics Conference Abstracts (Internet), 37D, p.P2.135_1 - P2.135_4, 2013/07
Long-pulse operation 
1000 s with 
5 is foreseen in ITER to demonstrate high neutron fluence scenarios which can be of use for the nuclear technology and for the TBM. In this study we address the viability of achieving ITER's long-pulse scenario in plasma regimes with H-mode confinement level by characterizing the current-density operational space and the achievable Q with long pulse burning phases. The EPED1 model with boundary conditions from SOLPS predicts no degradation of pedestal pressure with decreasing density in ITER. Modelling of core transport with 1.5D transport models carried out with pedestal parameters predicted by EPED1+SOLPS indicate that there is a large operational space for long pulse plasma operation with high fusion gain 5. Reducing the plasma density to 5-6 10m leads to an increased plasma temperature (similar pedestal pressure) which reduces the loop voltage and increases the duration of the burn phase to 1000 s with 5 for 13 MA at moderate normalised pressure, 2. Unlike the "hybrid" scenarios, these H-mode plasmas do not require specially shaped q profiles nor improved confinement in the core for the majority of the transport models considered in this study. Thus, these medium density H-mode plasma scenarios present an attractive alternative to hybrid scenarios to achieve ITER's long pulse.
林 伸彦; Parail, V.*; Koechl, F.*; 相羽 信行; 滝塚 知典; Wiesen, S.*; Lang, P. T.*; 大山 直幸; 小関 隆久
Nuclear Fusion, 51(10), p.103030_1 - 103030_8, 2011/10
被引用回数：6 パーセンタイル：27.22(Physics, Fluids & Plasmas)Two integrated core / scrape-off-layer / divertor transport codes TOPICS-IB and JINTRAC with links to MHD stability codes have been coupled with models of pellet injection to clarify effects of pellet on the behavior of edge localized modes (ELMs). Both codes predicted the following two triggering mechanisms. The energy absorption by the pellet and its further displacement due to the 
drift, as well as transport enhancement by the pellet, were found to be able to trigger the ELM. The ablated cloud of pellet absorbs the background plasma energy and causes a radial redistribution of pressure due to the subsequent drift. Further, the sharp increase in local density and temperature gradients in the vicinity of ablated cloud could cause the transient enhancement of heat and particle transport. Both mechanisms produce a region of increased pressure gradient in the background plasma profile within the pedestal, which triggers the ELM. The mechanisms have the potential to explain a wide range of experimental observations.
林 伸彦; Parail, V.*; Koechl, F.*; 相羽 信行; 滝塚 知典; Wiesen, S.*; Lang, P.*; 大山 直幸; 小関 隆久; JET-EFDA Contributors*
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Two integrated core / scrape-off-layer (SOL) / divertor transport codes TOPICS-IB and JINTRAC with links to MHD stability codes have been coupled with models of pellet injection to clarify effects of pellet on the behavior of edge localized modes (ELMs). The energy absorption by pellet and its further displacement due to EB drift as well as transport enhancement by the pellet were found to be able to trigger the ELM. The ablated cloud of pellet absorbs the background plasma energy and causes the radial redistribution of pressure due to the subsequent EB drift. On the other hand, the sharp increase in local density and temperature gradients in the vicinity of ablated cloud could cause transient enhancement of heat and particle transport. Both mechanisms produce a region of an increased pressure gradient in the background plasma profile within the pedestal, which triggers the ELM. The mechanisms have the potential to explain a wide range of experimental observations.
林 伸彦; Parail, V.*; Koechl, F.*; 相羽 信行; 滝塚 知典; Wiesen, S.*; Lang, P. T.*; 大山 直幸; 小関 隆久
no journal, ,
Two integrated core / scrape-off-layer / divertor transport codes TOPICS-IB and JINTRAC with links to MHD stability codes have been coupled with models of pellet injection to clarify effects of pellet on the behavior of edge localized modes (ELMs). Both codes predicted the following two triggering mechanisms. The energy absorption by the pellet and its further displacement due to the EB drift, as well as transport enhancement by the pellet, were found to be able to trigger the ELM. The ablated cloud of pellet absorbs the background plasma energy and causes a radial redistribution of pressure due to the subsequent EB drift. Further, the sharp increase in local density and temperature gradients in the vicinity of ablated cloud could cause the transient enhancement of heat and particle transport. Both mechanisms produce a region of increased pressure gradient in the background plasma profile within the pedestal, which triggers the ELM. The mechanisms have the potential to explain a wide range of experimental observations.
