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Observation of Lower Hybrid Current Drive Improved Confinement With a Graphite Probe at the Last Closed Flux Surface of the HT—7 Tokamak

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Chinese Physics Letters 2002年第9期19卷 1316-1318页

作者：徐国盛万宝年等 instituteofplasmaphysics ChineseAcademyofSciencesHefei230031

High time resolution measurements of the electrostatic fluctuations, radial electric field Er and turbulence-induced electron flux Γe have been performed across the transition of lower hybrid current drive improved confinement with a graphite Langmuir probe array at the last closed flux surface of the HT-7 tokamak. The decrease of Γe is dominated by the suppression of fluctuation levels, which follows the change of Er. A reversal of the poloidal propagation direction of turbulence demonstrates that the poloidal propagation is dominated by Er×Bφ drift. The enhancement of poloidal coherence accompanies the fluctuation suppression, which suggests the subtle variation of turbulence features.

关键词： Turbulent Flow MAGNETIC SURFACES graphene Graphite flux current drive Tokamak devices Hybrid electric vehicles HT-7 TOKAMAK Probes HYBRID Suppression propagation direction

Ohmic Radio-Frequency Synergy Current Drive and Transformer Recharging Experiments in the HT-7 Tokamak

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Chinese Physics Letters 2005年第7期22卷 1721-1724页

作者：陈忠勇万宝年石跃江胡立群徐(han)东 instituteofplasmaphysics ChineseAcademyofSciencesHefei230031

Lower hybrid current drive (LHCD) experiments for investigating the interaction between lower hybrid (LH) wave and residual dc electric field were performed in extensive plasma parameter ranges in the HT-7 superconducting tokamak. The experimental results are well fitted to the Karney–Fisch theory on the efficiency of LH waves energy converted to poloidal magnetic field energy. The fraction of absorbed LH power is about 0.75 for the HT-7 machine, and the upshift of the LH-wave parallel refraction index during LHCD experiments have been derived by the optimizing fitting parameters. The LH wave is also used for the transformer recharging when the plasma current is maintained unchanged. The highest efficiency about 7% has been achieved in HT-7 machine.

关键词： LH MHD LHCD

Naturally Occurring Velocity Shear Layer at the Plasma Edge of HT-7 Tokamak

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Chinese Physics Letters 2004年第1期21卷 137-139页

作者：徐国盛万宝年宋梅 instituteofplasmaphysics ChineseAcademyofSciencesHefei230031

A naturally occurring velocity shear layer was observed at the plasma edge of HT-7 tokamak in regular ohmic heated discharges. One fast reciprocating Langmuir probe was used to measure all quantities in the radial force balance equation for main ion, which enables us to present the first report about the radial force balance in the boundary region of the HT-7 tokamak. The sharp gradient of radial electric field and the reduced fluctuation correlation and turbulent particle flux characterized the edge velocity shear layer. It was found that the shear of turbulence poloidal velocity was dominated by the E x B flow shear and the poloidal rotation determined the structure of radial electric field profile and as a result the E x B flows.

关键词： Instrumentation and measurement Plasma physics

Lower Hybrid Wave Current Drive Efficiency on the HT-7 Tokamak

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Chinese Physics Letters 2005年第4期22卷 900-903页

作者：陈忠勇万宝年石跃江胡立群徐旵东李国超 instituteofplasmaphysics ChineseAcademyofSciencesHefei230031

Lower hybrid (LH) wave current drive efficiency on our HT-7 tokamak has been investigated based on the hot electrical conductivity theory. The interaction of the residual toroidal electric field with fast electrons has been included in the determination of current drive efficiency. The LH wave power scan was performed in the plasma parameter ranges of Ip = 50–156kA, e = 0.5×1019–1.6×1019m−3, PLH = 50–350kW. The current drive efficiency is derived to be about 0.1×1019–0.4×1019Am−2W−1 on the HT-7 tokamak, which depends on the electron density and the LH wave phase velocity. At the electron density of about 1.5×1019m−3, with the LH wave parallel refraction index peaked at 1.8, the highest current drive efficiency was obtained. A more generally normalized method is introduced to analyse the experimental data, which combines all the data in one curve. The normalized parameters are independent of the plasma parameters.

关键词： HT-7托卡马克热电导体混合波电流驱动效率相速度

Improved Edge Confinement due to Ion Cyclotron Radio Frequency boronization in the HT—7 Tokamak

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Chinese Physics Letters 2003年第6期20卷 881-884页

作者： XUGuo-Sheng WANBao-Nian SONGMei LINGBi-Li instituteofplasmaphysics ChineseAcademyofSciencesHefei230031

The phenomena of improved edge confinement due to ion cyclotron radio frequency boronization were observed with a fast reciprocating Langmuir probe in the HT-7 tokamak. A strong shear layer of radial electric field was produced in the plasma edge region, which resulted in the formation of an edge transport barrier. Consequently, the edge profiles of electron density were steepened, and both the absolute and relative fluctuation levels were suppressed by the shearing E×B flows. Concomitant reduction of the coherence between electron density and poloidal electric field fluctuations and the change of their cross-phase resulted in turbulent particle flux dropping by more than a half at the plasma edge. This demonstrates the de-correlation effect of turbulence and its contribution to edge transport. The results presented here suggest a link between wall conditions and boundary plasma physics, especially an interaction between atomic processes and turbulence through the formation of radial electric field shear at the plasma edge.

关键词： radiofrequency Confinement EDGE PLASMAS Electric fields Electron density HT-7 TOKAMAK PHENOMENON Cyclotrons Turbulent Flow Edge of a figure or solid Tokamak devices

Effect of N^+ beam exposure on the activities of Mn-SODand catalase in Deinococcus radiodurans

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Nuclear Science and Techniques 2000年第4期11卷 280-286页

作者： SONGDao-Jun CHENRuo-Lei 等 CenterofFengleIonBeamBioengineering InstituteofPlasmaPhysicstheChineseAcademyofSciencesHefei230031 CenterofFengleIonBeamBioengineering InstituteofPlasmaPhysicstheChineseAcademyofSciencesHefei23003

Though the radiation-resistant bacteria Deinococcus radiodurans (D. radiodurans) have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. In this report, the superoxide dismutase (SOD) and catalase (CAT) activities produced in bacteria (*** AS1.633) and their change caused by 20 keV N+ beam exposure were examined. Results showed that the activities of the enzymes were increased in the case of N+ beam exposure from 8×1014 ions/cm2 to 6×1015 ions/cm2. In addition, the treatment of H2O2 and [CHCl3+CH3CH2OH] and the measurement of absorption spectrum showed that the increase of whole SOD activity resulted from inducible activities of Mn-SOD in (a sub^type) *** AS1.633. These results suggested that these bacteria possess inducible defense mechanisms against the deleterious effects of oxidization.

关键词：氮离子束辐照 Mn-SOD 过氧化氢酶锰超氧化物歧化酶辐射效应

Preliminary Observation on Coordination of Pellet Injection and Ion Bernstein Wave on a HT—7 Tokamak

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Chinese Physics Letters 2002年第5期19卷 701-703页

作者：杨愚赵燕平等 instituteofplasmaphysics ChineseAcademyofSciencesHefei230031

A pellet injection (PI) experiment was performed during the application of the ion Bernstein wave on a HT-7 tokamak. A preliminary coordination effect was observed. With a lower wave power, shortly after PI, the coupling of the wave was enhanced, and the particle confinement was improved. With higher power, off-axis heating for 15% at about a/3 in the low field side was observed.

关键词： Wave power

Influence of Particle Coordination Number in Nanoporous TiO2 Films on the Performance of Dye-Sensitized Solar Cell Modules

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Chinese Physics Letters 2005年第2期22卷 493-495页

作者：胡林华戴松元王孔嘉 instituteofplasmaphysics ChineseAcademyofSciencesHefei230031

The average particle coordination number, one of the characters concerningthe pore size distribution in the films, was introduced in dye-sensitized solar cell (DSC) moduleswith the size of 15 cm x 20 cm and the active area of 187.2 cm(2) to estimate the performance of aTiO2 nanoporous film, which is critical to the future DSC production. The current-voltagemeasurement of the DSC modules indicates that the average particle coordination number in the rangeof 4-5 typically appears in nanocrystalline TiO2 films used in the DSC modules and that the averagecoordination number could provide a very valuable way to evaluate the performance of nanoporous TiO2films.

关键词： ELECTRON-TRANSPORT DIFFUSION SIZE

First Measurement of the Magnetic Turbulence Induced Reynolds Stress in a Tokamak

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Chinese Physics Letters 2003年第12期20卷 2210-2213页

作者：徐国盛万宝年宋梅 instituteofplasmaphysics ChineseAcademyofSciencesHefei230031

Reynolds stress component due to magnetic turbulence was first measured in the plasma edge region of the HT-7 superconducting tokamak using an insertable magnetic probe. A radial gradient of magnetic Reynolds stress was observed to be close to the velocity shear layer location; however, in this experiment its contribution to driving the poloidal flows is small compared to the electrostatic component. The electron heat transport driven by magnetic turbulence is quite small and cannot account for the total energy transport at the plasma edge.

关键词： First Measurement Magnetic Turbulence Induced Reynolds Stress Tokamak