By ECH under a steady By field, a closed field equilibrium of a low aspect ratio as low as R/a = 1.4 is spontaneously formed in the LATE device. After the spontaneous formation, the plasma current has increased furthe...By ECH under a steady By field, a closed field equilibrium of a low aspect ratio as low as R/a = 1.4 is spontaneously formed in the LATE device. After the spontaneous formation, the plasma current has increased further up to Ip = 7.2 kA by 2.45 GHz, 30 kW and Ip = 11 kA by 5 GHz, 120 kW, by increasing the microwave power with a slow ramp of By for the equilibrium of the plasma loop at larger currents. Both amount to 12% of the total toroidai coil current. ECH/ECCD at 2nd harmonic resonance of EBW supports the plasma. An outline of the theoretical considerations for the formation process is presented.展开更多
在低方面比率花托试验(迟了)设备，血浆电流被开始并且 ramped 直到完全由在电子回旋加速器( EC )的微波功率的 20 kA 有外部垂直领域 B <SUB 的一个斜面的频率的范围>为更全体的血浆花托的光线的平衡的 v </SUB>电流。...在低方面比率花托试验(迟了)设备，血浆电流被开始并且 ramped 直到完全由在电子回旋加速器( EC )的微波功率的 20 kA 有外部垂直领域 B <SUB 的一个斜面的频率的范围>为更全体的血浆花托的光线的平衡的 v </SUB>电流。大小建议在大约 200 keV 的精力范围的一条精力充沛的电子尾巴带电流。线平均电子密度，建议那条尾巴是高，比血浆截止密度，电子可能被从发射电磁波变换模式的电子伯恩斯坦波浪驾驶。展开更多
Investigation of experimental configuration for the electron Bernstein wave （EBW） heating by using the existing electron cyclotron heating （ECH） antennas on LHD was performed. By using an antenna installed in the ...Investigation of experimental configuration for the electron Bernstein wave （EBW） heating by using the existing electron cyclotron heating （ECH） antennas on LHD was performed. By using an antenna installed in the lower port, direct oblique launching of the extraordinary （X-） mode from the high magnetic field side （HFS） is available. Since the parallel component of the refractive index （NIF） varies during propagation because of the inhomogeneity of the magnetic field, NH can be zero when the launched X-mode crosses the fundamental electron cyclotron resonance （ECR） layer even NⅡ is noonzero initially. In such a condition, if the electron density is above a certain level the obliquely launched X-mode can pass the fundamental ECR layer without being damped out and can be mode-converted to EBW that is absorbed at the Doppler shifted ECR layer. By using an antenna installed in the horizontal port, oblique launching from the lower magnetic field side （LFS） toward the over-dense plasma is available. Excitation of EBW via the mode conversion process of ordinary mode（O）-extraordinary mode（X）-electron Bernstein wave （B） is expected with the O-mode launching toward an appropriate direction. The O-X-B mode conversion rate and the region of power deposition were surveyed by varying the magnetic field strength and the launching direction. The results of the survey suggest that efficient heating in the core region is difficult by using the existing antenna. Rearrangement of the final mirror of the launching antenna may be needed.展开更多
Electron orbits under the external vertical field （Bv） and the self poloidal field of the toroidal plasma current in a toroidal geometry are investigated by using analytic model fields in order to search for the con...Electron orbits under the external vertical field （Bv） and the self poloidal field of the toroidal plasma current in a toroidal geometry are investigated by using analytic model fields in order to search for the conditions of occurence of appropriate confinement asymmetry of fast electrons along the field lines. This asymmetry efficiently and quickly generates a toroidal current, which may close the field lines in ECH-started plasmas. It is analytically shown that the characteristics of confinement asymmetry depend on the product of the major radius and the strength of the external vertical field. The results suggest that in large devices By should be lowered and also some artificial means to speed up the pitch angle scattering for the fast electrons at a higher energy range are beneficial to generate the toroidal current in order to close the filed展开更多
In the present paper we obtain and extend the boundedness property of the Adams type for multilinear fractional integral operators. Also, we deal with the Olsen type inequality.
Let K<delta>, 0 < <delta>±1, be the Kakeya maximal operator defined as the supremum of averages over tubes of the eccentricity <delta>. The (so-called) Fefferman-Stein-type inequality: $|| {K...Let K<delta>, 0 < <delta>±1, be the Kakeya maximal operator defined as the supremum of averages over tubes of the eccentricity <delta>. The (so-called) Fefferman-Stein-type inequality: $|| {K_\delta f} ||_{L^d({{\rm R}^d,w})} \le C_d ({1 \over \delta})^{(d - 2)/2d}(\log ({1 \over \delta } ))^{\alpha_d} || f ||_{L^d ({\rm R}^d,K_{\delta}w})}$is shown, where Cd and <alpha>d are constants depending only on the dimension d and w is a weight. The result contains the exponent (d-2)/2d which is smaller than the exponent (d-2)(d-1)/d(2d-3) obtained in [7].展开更多
Two experimental tests of three-storied reinforced concrete structural walls having large openings were performed.Based on an original macro model,a multiple modified macro-model was proposed to develop a simple metho...Two experimental tests of three-storied reinforced concrete structural walls having large openings were performed.Based on an original macro model,a multiple modified macro-model was proposed to develop a simple method to design a reinforced concrete structural wall with large openings and various opening locations.The interaction between reinforcement ties and concrete struts formed along the perimeter of openings was neglected in the original model.However,the strut-and-tie node was proposed to take account of such interaction in the proposed model.The predicted behavior of two specimens using such a proposed model was compared with the experimental results.It is shown that the behavior of structural walls with large openings could be modeled well using the proposed model.Moreover,the study indicates that the proposed model is applicable even in cases of multi-story structural walls having large openings and various opening locations.展开更多
基金supported in part by the JSPS-CAS Core University Program in the field of Plasma and Nuclear Fusion
文摘By ECH under a steady By field, a closed field equilibrium of a low aspect ratio as low as R/a = 1.4 is spontaneously formed in the LATE device. After the spontaneous formation, the plasma current has increased further up to Ip = 7.2 kA by 2.45 GHz, 30 kW and Ip = 11 kA by 5 GHz, 120 kW, by increasing the microwave power with a slow ramp of By for the equilibrium of the plasma loop at larger currents. Both amount to 12% of the total toroidai coil current. ECH/ECCD at 2nd harmonic resonance of EBW supports the plasma. An outline of the theoretical considerations for the formation process is presented.
基金the budget codes NIFS07ULRR501-3,518,NIFS07KLRR303a grant-in-aid for scientific research of MEXT JAPAN,2008 19740347the JSPS-CAS Core-University program in the field of Plasma and Nuclear Fusion
文摘Investigation of experimental configuration for the electron Bernstein wave （EBW） heating by using the existing electron cyclotron heating （ECH） antennas on LHD was performed. By using an antenna installed in the lower port, direct oblique launching of the extraordinary （X-） mode from the high magnetic field side （HFS） is available. Since the parallel component of the refractive index （NIF） varies during propagation because of the inhomogeneity of the magnetic field, NH can be zero when the launched X-mode crosses the fundamental electron cyclotron resonance （ECR） layer even NⅡ is noonzero initially. In such a condition, if the electron density is above a certain level the obliquely launched X-mode can pass the fundamental ECR layer without being damped out and can be mode-converted to EBW that is absorbed at the Doppler shifted ECR layer. By using an antenna installed in the horizontal port, oblique launching from the lower magnetic field side （LFS） toward the over-dense plasma is available. Excitation of EBW via the mode conversion process of ordinary mode（O）-extraordinary mode（X）-electron Bernstein wave （B） is expected with the O-mode launching toward an appropriate direction. The O-X-B mode conversion rate and the region of power deposition were surveyed by varying the magnetic field strength and the launching direction. The results of the survey suggest that efficient heating in the core region is difficult by using the existing antenna. Rearrangement of the final mirror of the launching antenna may be needed.
文摘Electron orbits under the external vertical field （Bv） and the self poloidal field of the toroidal plasma current in a toroidal geometry are investigated by using analytic model fields in order to search for the conditions of occurence of appropriate confinement asymmetry of fast electrons along the field lines. This asymmetry efficiently and quickly generates a toroidal current, which may close the field lines in ECH-started plasmas. It is analytically shown that the characteristics of confinement asymmetry depend on the product of the major radius and the strength of the external vertical field. The results suggest that in large devices By should be lowered and also some artificial means to speed up the pitch angle scattering for the fast electrons at a higher energy range are beneficial to generate the toroidal current in order to close the filed
基金supported financially by Grant-in-Aid for Young Scientists (B) (Grant No. 21740104), Japan Society for the Promotion of Science
文摘In the present paper we obtain and extend the boundedness property of the Adams type for multilinear fractional integral operators. Also, we deal with the Olsen type inequality.
基金Supported by Japan Society for the Promotion of Sciences and Fujukai Foundation.
文摘Let K<delta>, 0 < <delta>±1, be the Kakeya maximal operator defined as the supremum of averages over tubes of the eccentricity <delta>. The (so-called) Fefferman-Stein-type inequality: $|| {K_\delta f} ||_{L^d({{\rm R}^d,w})} \le C_d ({1 \over \delta})^{(d - 2)/2d}(\log ({1 \over \delta } ))^{\alpha_d} || f ||_{L^d ({\rm R}^d,K_{\delta}w})}$is shown, where Cd and <alpha>d are constants depending only on the dimension d and w is a weight. The result contains the exponent (d-2)/2d which is smaller than the exponent (d-2)(d-1)/d(2d-3) obtained in [7].
基金Project supported by the Grants-in-Aid for Scientific Research of Japan (No. 16206056)the Scientific Research Foundation for Talent Introduction (No. 113201-811132)
文摘Two experimental tests of three-storied reinforced concrete structural walls having large openings were performed.Based on an original macro model,a multiple modified macro-model was proposed to develop a simple method to design a reinforced concrete structural wall with large openings and various opening locations.The interaction between reinforcement ties and concrete struts formed along the perimeter of openings was neglected in the original model.However,the strut-and-tie node was proposed to take account of such interaction in the proposed model.The predicted behavior of two specimens using such a proposed model was compared with the experimental results.It is shown that the behavior of structural walls with large openings could be modeled well using the proposed model.Moreover,the study indicates that the proposed model is applicable even in cases of multi-story structural walls having large openings and various opening locations.
