Studies of structure and dynamics of toroidal plasma using twin heavy ion beam probes

使用双重离子束探针研究环形等离子体的结构和动力学

• 批准号: 15360497
• 负责人: FUJISAWA Akihide
• 金额: $ 7.94万
• 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 (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15360497/
• 关键词: zonal flows; turbulence; heavy ion beam probe; electric field; nonlinear coupling; toroidal plasma; bifurcation; CHS; 内部電場; 長距離相関; 乱流輸送; 自励振動; アルベン固有モード; 揺動スペクトル; プラズマ閉じ込め

Since 1982 when H-mode was discovered, a number of structures caused by bifurcation in turbulence transport have been found in toroidal plasma The researchover twenty years has shown that electric field shear can reduce the turbulence and resultant transport to form the local transport barrier and cause the bifurcated structures.Recent simulation and theories expect that the plasma turbulence can generate macroscopic flow through Reynolds stress, and the interaction between macro-scale flow and micro-scale turbulence can affect the saturation level of turbulence and the resultant transport. This is ascribed to the following reasons ; (1)a quasi-energy conservation law is valid for the relation between zonal flow to cause no cross-field transport and turbulence, (2)the time-dependent shear structure of zonal flow also reduces the turbulence. In CHS, using twin heavy ion beam probes constructed with help of this grant-in-aid, the existence of zonal flow was proven in 2004. This is the first achievement in the world. Further more, in 2005 the experiment to prove the nonlinear linkage between zonal flow and turbulence was performed. The experiment successfully verified the existence of such nonlinear interaction between zonal flow and turbulence. In other words, the quasi-energy conservation law was proven using the efficient use of the twin heavy ion beam probes.The phenomena of zonal flow are ubiquitous in nature. The example includes Jovian belt and zones, terrestrial jet stream, solar tacocline and so on. The achievement of this project should give deep insight to the turbulence phenomena widely observed in the universe.

自1982年发现H模式以来，在环形等离子体中发现了多种由湍流输运分岔引起的结构。二十多年来的研究表明，电场剪切可以减少湍流和由此产生的输运，形成局域输运势垒，导致最近的模拟和理论预计等离子体湍流可以通过雷诺应力产生宏观流动，宏观尺度流动和微观尺度湍流之间的相互作用可以影响湍流的饱和水平和由此产生的传输。这是由于以下原因； (1)准能量守恒定律对于不引起跨场传输和湍流的纬向流之间的关系是有效的，(2)纬向流的时间相关剪切结构也减少了湍流。在CHS中，利用该资助构建的双重离子束探针，于2004年证明了层流的存在，这是世界上的首次成就。此外，2005年进行了证明纬向流与湍流之间非线性联系的实验。实验成功验证了纬向流与湍流之间这种非线性相互作用的存在。换句话说，准能量守恒定律是通过有效利用双重离子束探针而得到证明的。层流现象在自然界中是普遍存在的。例子包括木星带和地带、陆地急流、太阳塔科斜层等。该项目的成就应该能够深入了解宇宙中广泛观察到的湍流现象。

项目成果

Spectrograph of electric field fluctuation in toroidal helical plasma

• DOI: 10.1088/0741-3335/48/4/s03
• 发表时间: 2005-09
• 期刊: Plasma Physics and Controlled Fusion
• 影响因子: 2.2
• 作者: A. Fujisawa;K. Itoh;A. Shimizu;H. Nakano;S. Ohsima;H. Iguchi;K. Matsuoka;S. Okamura;S. Itoh;P. Diamond

Turbulence and transport characteristics of a barrier in a toroidal plasma

• DOI: 10.1088/0741-3335/48/4/s15
• 发表时间: 2006-04-01
• 期刊: PLASMA PHYSICS AND CONTROLLED FUSION
• 影响因子: 2.2
• 作者: Fujisawa, A.;Shimizu, A.;Diamond, P. H.
• 通讯作者: Diamond, P. H.

藤澤 彰英: "Prescription for density profile reconstruction using a heavy ion beam probe"Review of Scientific Instruments. 74. 3335-3340 (2003)

Akihide Fujisawa：“使用重离子束探针重建密度剖面的处方”科学仪器评论 74. 3335-3340 (2003)。

藤澤 彰英: "Experimental studies of structural bifurcation in stellarator plasmas"Plasma Physics and Controlled fusion. 45. R1-R88 (2003)

Akihide Fujisawa：“仿星器等离子体中结构分岔的实验研究”等离子体物理和受控聚变。R1-R88 (2003)。

Internal transport barrier and bifurcation phenomena in stellarators

仿星器中的内部传输势垒和分叉现象

• 发表时间: 2004
• 期刊: Fusion Science and Technology 46
• 作者: A.Fujisawa;K.Itoh;H.Iguchi;K.Matsuoka;et al.(共著);A.Fujisawa
• 通讯作者: A.Fujisawa