Plasma Confinement Improvement with a Local Island Divertor

使用本地岛偏滤器改善等离子体限制

• 批准号: 16206092
• 负责人: KOMORI Akio
• 金额: $ 31.53万
• 依托单位: National Institute for Fusion Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16206092/
• 关键词: divertor; magnetic island; edge plasma control; edge plasma; ergodic layer; heliotron configuration; LID

During the research for four years, we discovered a high density operational regime by the central fuelling with the pellet injection and the strong pumping with the Local Island Divertor (LID). In this discharge, the superdense core region with the density more than 5×10^<20> m_<-3> and the temperature of〜0.8 keV is maintained by an Internal Diffusion Barrier (IDB) formed in the confinement region. These high parameters in the core plasma consequently provided the highest plasma performance (fusion triple product, n_0T_0τe=2.8×10^<19>m_<-3>keVs) obtained so far in the Large Helical Device (LHD). The LID is a kind of island divertor which utilizes an m/n=1/1 magnetic island artificially induced by the perturbation coils. The LID has the efficient pumping capability with its closed configuration and strong pumping system despite its compactness, which therefore brings about low particle recycling, i.e. low edge density.In the recent experiments, however, it was found that such a high de … More nsity discharge with peaked electron density profile could be obtained not only in the LID configuration but in the Helical Divertor (HD) configuration, if only the reduced recycling could be achieved by the exhaustive wall conditioning. In the HD configuration with large flexibility of the magnetic field configuration, experiments were performed shifting the magnetic axis from standard position to outward shifted one. After the optimization of operational conditions, it was often observed that the central density collapse (CDC) took place with the increase of the central plasma pressure. In the CDC, the abrupt density decay at the center and the increase at the edge region were observed, suggesting the particle flush from the core region. In order to avoid the CDC, an attempt to suppress the Shafranov shift (outward shift of the plasma column) was made by changing the plasma shape. An effective result was obtained in the experiment with the expansion of the plasma parameters. The impurity behavior during the high density discharge was also investigated. In spite of the peaked density profile with IDB, no serious impurity accumulation was observed, although a certain quantity of carbon was sputtered on the surface of the divertor plates. This experimental result was also demonstrated by the numerical calculation with the EMC3-EIRENE code which suggests the strong parallel flow in the ergodic region to play an important role in impurity screening with its strong frictional force. Less

在四年的研究中，我们发现了通过注射颗粒的中央加油和与当地岛分流（LID）的强力泵送的高密度运营状态。在此放电中，密度大于5×10^<20> m _ <-3>的超密集核区域和〜0.8 keV的温度通过在约束区域形成的内部扩散屏障（IDB）维持。因此，核心等离子体中的这些高参数提供了最高的等离子性能（Fusion Triple产品，N_0T_0τE= 2.8×10^<19> M _ <-3> KEVS到目前为止在大型螺旋设备（LHD）中获得。盖子是一种岛分流器，它利用M/N = 1/1磁岛通过扰动线圈人为诱导。 The LID has the efficient pumping capability with its closed configuration and strong pumping system destination its compactness, which therefore brings about low particle recycling, i.e. l​​ow edge density.In the recent experiments, however, it was found that such a high de … More nsity discharge with peaked electron density profile could be obtained not only in the LID configuration but in the Helical Divertor (HD) configuration, if only the reduced recycling could可以通过详尽的壁条件来实现。在具有磁场构型灵活性的高清配置中，进行了实验，将磁轴从标准位置转移到向外移动。在优化操作条件之后，经常观察到中央密度塌陷（CDC）随着中央血浆压力的增加而发生。在CDC中，观察到中心的突然衰变和边缘区域的增加，表明粒子从核心区域冲洗。为了避免CDC，通过更改等离子体形状进行抑制Shafranov偏移（等离子体柱的向外移动）。在血浆参数扩展的实验中，获得了有效的结果。还研究了高密度放电期间的杂质行为。尽管具有IDB的峰值密度谱，但仍未观察到严重的杂质积累，尽管在分离板的表面上溅射了一定数量的碳。通过使用EMC3-欧元代码进行数值计算，这表明了这一实验结果，这表明厄基德区域中强的平行流具有强大的摩擦力筛查中的杂质筛查中发挥重要作用。较少的

项目成果

Formation and healing of n=1 magnetic island in LHD equilibrium

LHD 平衡中 n=1 磁岛的形成和愈合

• 发表时间: 2005
• 期刊: Nuclear Fusion 45
• 作者: H.Kurishita;S.Matsuo;H.Arakawa;S.Kobayashi;K.Nakai;T.Takida;K.Takebe;M.Kawai;R.Kanno
• 通讯作者: R.Kanno

Edge plasma control by helical and local island divertors in LHD

LHD 中通过螺旋和局部岛偏滤器进行边缘等离子体控制

• 发表时间: 2007
• 作者: J. Miyazawa;et al.;森崎友宏;森崎 友宏;H. Yamada;森崎友宏;増崎貴;宮澤順一;坂本隆一;小林政弘;宮澤 順一;森崎 友宏;坂本 隆一;増崎 貴;S. Masuzaki;S. Masuzaki;S. Masuzaki;M. Kobayashi;J. Miyazawa;R. Sakamoto;K. Tanaka;J. Miyazawa;R. Sakamoto;田中 謙治;宮澤 順一;坂本 隆一;R. Sakamoto;K. Tanaka;R. Sakamoto;田中 謙治;坂本 隆一;森崎友宏;森崎 友宏;K. Tanaka;田中 謙治;H. Yamada;山田 弘司;J. Miyazawa;宮澤 順一;増崎 貴;S. Masuzaki;T. Morisaki
• 通讯作者: T. Morisaki

Three-dimensional proton trajectory analyses and simulation of neutral particle transport in an ICRF heated long pulse discharge on the large helical device

大型螺旋装置上 ICRF 加热长脉冲放电中的三维质子轨迹分析和中性粒子输运模拟

• 发表时间: 2005
• 期刊: Journal of Nuclear Materials 337-339
• 作者: A. Ushida;T. Sugiyama;Y. Enokida;I. Yamamoto;Kuniyuki Omagari et al.;M.Shoji
• 通讯作者: M.Shoji

IDB-SDC放電における周辺プラズマの役割

外周等离子体在 IDB-SDC 放电中的作用

• 发表时间: 2007
• 作者: 長山好夫;成嶋吉朗(3番目);大藪修義(4番目);森崎友宏(11番目);他14名;長山好夫;森崎友宏;森崎友宏;森崎友宏;森崎 友宏;鈴木康浩;小林政弘;増崎貴;森崎友宏;森崎友宏;森崎友宏;小林政弘;増崎貴;小林政弘;小林 政弘;森崎 友宏
• 通讯作者: 森崎 友宏

Flux Surface Mapping in LHD

LHD 中的通量表面映射

• 发表时间: 2007
• 作者: T.Morisaki;et. al.
• 通讯作者: et. al.