Nuclear Fusion and Plasma Physics

Relativistic effects of electromagnetic waves in moving unmagnetized plasma

HUANG Ye

2009, 29(3): 193-198.

Asbtract ( )

PDF (1922KB) ( )

References | Related Articles | Metrics

The dispersion relations of superluminal waves for the longitudinal collective modes in unmagnetized, collisionless and homogeneous relativistic electron-positron plasmas are derived. Using the standard technique of successive approximations, an analytic study of longitudinal dispersion equations in two limiting cases is presented. The full dispersion equations are transformed so that they are well suited for numerical evaluation in the temperature range where a fully relativistic treatment is needed. Using the numerical simulation method, we obtain the full dispersion curve which can’t get from the analytic method.

Linear dispersion relation for longitudinal modes of two temperature electron-positron plasma in relativistic regime

WANG Hao, LIU San-qiu, DU Jian-qiang

2009, 29(3): 199-202.

Asbtract ( )

PDF (365KB) ( )

References | Related Articles | Metrics

The dispersion relations of superluminal waves for the longitudinal collective modes in unmagnetized, collisionless and homogeneous relativistic electron-positron plasmas are derived. Using the standard technique of successive approximations, an analytic study of longitudinal dispersion equations in two limiting cases is presented. The full dispersion equations are transformed so that they are well suited for numerical evaluation in the temperature range where a fully relativistic treatment is needed. Using the numerical simulation method, we obtain the full dispersion curve which can’t get from the analytic method.

Application of the concentric diamagnetic coils on HL-2A tokamak magnetic measurements

XIE Wei-min, JI Xiao-quan, FENG Bei-bin, DONG Chun-feng, YANG Qing-wei

2009, 29(3): 203-207.

Asbtract ( )

PDF (1359KB) ( )

References | Related Articles | Metrics

The principle of magnetic measurements on the concentric coils of HL-2A tokamak, and the design of concentric circles system are introduced, including identification of the area difference for the coils and integral circuit design. Through an effective compensation for stray magnetic field, concentric circles diamagnetic measurement system can get a higher signal-to-noise ratio, and therefore reliable plasma diamagnetic signal in complex discharge conditions can be obtained.

Analysis on electromagnetic force of toroidal field coils for HL-2M tokamak

SHANG Sheng-feng, LIU De-quan, LI Qiang, LI Guang-sheng, QIAO Tao, ZHOU Hui, RAN Hong, CAI Li-jun

2009, 29(3): 208-213.

Asbtract ( )

PDF (2344KB) ( )

References | Related Articles | Metrics

To provide the stress information for the design of the turn-over structure (TOS) and other support components, the stress on the toroidal tield coils (TFC) has been calculated by the electromagnetic-structural, finite-element module in ANSYS code. The results show that the maximum shear stress value about 7.2MPa on the TFC is less than the allowable value, at the normal routine.

Simulation of HALO current in EAST superconducting tokamak

PENG Yu-hua, SONG Yun-tao, WU Song-tao

2009, 29(3): 214-218.

Asbtract ( )

PDF (1072KB) ( )

References | Related Articles | Metrics

Based on the EAST superconducting tokamak, the calculation method and process of HALO current are given. The time evolutions of the plasma current and HALO current during the course of plasma disrupting are simulated by the free energy method.

Study on HTS modules of HTS current leads for ITER

YANG Chang-chun, WU Song-tao, BI Yan-fang

2009, 29(3): 219-223.

Asbtract ( )

PDF (2204KB) ( )

References | Related Articles | Metrics

According to the demand of HTS current leads for ITER, 1/90 trials of three kinds of shunts made of Beryllium bronze (Be2%Cu), stainless steel (SS) and the binary metal (BeCu/SS) for the 68kA lead have been designed and tested. Performances of components of HTS module were studied, and the results of loss of flow accident were discussed in detail. Comparing to the Beryllium bronze shunt and stainless steel shunt, the HTS module made of the binary shunt can satisfy ITER requirements and increase safety and decrease the heat leak to the cold end.

Grill design and spectrum calculation of LHW antenna on HL-2M tokamak

BAI Xin-yu, ZENG Jian-er, RAO Jun

2009, 29(3): 224-228.

Asbtract ( )

PDF (1274KB) ( )

References | Related Articles | Metrics

The antenna for lower hybrid current driving on HL-2M tokamak is designed as 4?32 waveguide arrays. The width of grill is 9.9mm, the wall thickness is 3mm and the phase difference between two adjacent grills is 90?. The calculation shows that the reflectance R is 0.026 and the N|| corresponding the peak value is 2.375. The gradient of edge electron density has nothing to do with the N|| corresponding the peak value. But the larger electron density gradient of the plasma edge is, the smaller peak width is. When the phase difference between two adjacent grills is 81?and , is optimum, 0.2010, R is minimum, 0.0223 and the N|| corresponding the peak value is 2.125.

Preliminary analysis for gravity support and vacuum vessel of different cross-sections on HL-2M tokamak

LI Yong, LIU De-quan, RAN Hong, CAI Li-jun, CAO Zeng, LI Qiang

2009, 29(3): 229-233.

Asbtract ( )

PDF (1709KB) ( )

References | Related Articles | Metrics

The preliminary analysis of vacuum vessel of different cross-section has been carried out with the ANSYS code. The results show that the strength of vacuum vessel of round arc cross-section is better than that of polygonal cross-section. The vacuum vessel with 8 and 16 sets of gravity support component is respectively analyzed. The distributing of gravity support components is optimized according to analysis results, thereby the thermal stress decreases during baking.

Safety and efficiency of the resistive heat exchanger for HTS high-rated current leads

BI Yan-fang, DING Kai-zhong

2009, 29(3): 234-238.

Asbtract ( )

PDF (861KB) ( )

References | Related Articles | Metrics

The relative theory of the safety and efficiency as well as experiment are presented for the high-rated current lead design. The experiment results indicate the safety property is associated to current density of the resistive heat exchanger (HEX) and temperature margin of the HTS module. The HEX cooling mass flow rate depends on the HEX efficiency, which relates to heat transfer area and coefficient etc.

Development of anode high voltage power supply system for ECRH of HL-2A tokamak

CHEN Wen-guang, KANG Zi-hua, WANG Ming-wei, RAO Jun

2009, 29(3): 239-243.

Asbtract ( )

PDF (1790KB) ( )

References | Related Articles | Metrics

The anode high voltage power supply system consist of DC high-voltage power supply (HVPS) and pulse modulator. SCR is used to vary AC input voltage of the step-up transformer by controlling the trigger phase in the HVPS, and regulate the DC output voltage linearly at the potential of low-end via BJT, Dual closed-loop control technology is applied in the controller, and its maximum output is at 30kV and 130mA. Tetrode is the core component of the modulator. The circuit design is optimized by using the simulation software. Test and HL-2A discharge experimental results show that the power supply system is designed with some characteristics of output scale widely, low ripple and modulate quickly.

Realization of toroidal field power supply control system for J-TEXT tokamak

QIU Sheng-shun, ZHUANG Ge, ZHANG Ming, FANG Jian-ming

2009, 29(3): 244-247.

Asbtract ( )

PDF (1347KB) ( )

References | Related Articles | Metrics

Based on the integrated development environment provided by QNX real-time operation system, the control system of toroidal field power supply is designed and developed. The system is proved to be reliable, stable and in real-time. It can control the power supply successfully to produce a constant current up to 92.5kA lasting for 1s and 1.74T at the magnetic axis. In conclusion, the control system can meet the requirements of the J-TEXT routine operation at present.

HCN signal measuring and processing algorithm design in HT-7 tokamak

SHU Shuang-bao, LUO Jia-rong, LIU Lian-zhong, WANG Hua-zhong

2009, 29(3): 248-252.

Asbtract ( )

PDF (1954KB) ( )

References | Related Articles | Metrics

HCN signal can be used for measuring the plasma electron density. HCN interferometers and phase comparators are used in HT-7 tokamak for supplying HCN signal. According to the analysis of the signal, an HCN signal processing algorithm is designed, which includes baseline offset elimination, HCN signal overturn processing, and denoising with fuzzy logic filter method. Using the proposed algorithm, plasma electron density signals with high accuracy and low noise have been obtained in HT-7 tokamak experiment.

Design of EAST LHCD high power supply feedback control system based on PLC

HU Huai-chuan, SHAN Jia-fang

2009, 29(3): 253-257.

Asbtract ( )

PDF (2800KB) ( )

References | Related Articles | Metrics

Design of EAST LHCD -35kV/5.6MW high power supply feedback control system based on PLC is described. Industrial computer and PLC are used to control high power supply in the system. PID arithmetic is adopted to achieve the feedback control of voltage of high power supply. Operating system is base on real-time operating system of QNX. Good controlling properties and reliable protective properties of the feedback control system are proved by the experiment results.

Preliminary structure analysis for the first-wall of CH HCSB TBM

ZHAO Zhou, FENG Kai-ming, ZHANG Guo-shu, YUAN Tao

2009, 29(3): 258-263.

Asbtract ( )

PDF (2531KB) ( )

References | Related Articles | Metrics

Gravity analysis for the first-wall of CH HCSB TBM shows that the stress and displacement of first-wall caused by the gravity effect are too small and could be ignored. And the results of thermal-mechanical analysis for the first-wall show that the stress of Be armor is higher than allowable vaue, so it’s proposed to choice W/Cu alloy replaced Be as the armor of first-wall under considering the point of structure design.

Structure analysis of correction coils for ITER

ZENG Wen-bing, WU Wei-yue

2009, 29(3): 264-269.

Asbtract ( )

References | Related Articles | Metrics

The mechanical structure and support design of correction coils for ITER were introduced, and the magnetic field of correction coils was analyzed with finite element method. Then the structure was analyzed and the distributing of the support components is optimized. The primarily results showed that the correction coil system is proved to be reliable and safe.

Primary structure and seismic response analysis of the ITER transfer cask

WANG Fen-fen, YAO Da-mao, LI Ge

2009, 29(3): 270-274.

Asbtract ( )

PDF (1959KB) ( )

References | Related Articles | Metrics

The primary structure and the work situation of the ITER transfer cask were introduced. Based on the mode analysis of the transfer cask model, seismic spectrum response analysis was conducted by the finite element method. The results showed that the transfer cask was safe under seismic state. The results will provide some reference data for further optimization of structure design and future experiment of the transfer cask.

Design of alternant integrator on EAST tokamak

WANG Yong, JI Zhen-shan, LUO Jia-rong

2009, 29(3): 275-278.

Asbtract ( )

PDF (874KB) ( )

References | Related Articles | Metrics

Based on a kind of low drift integrator with auto-compensation, an alternant integrator has been designed. The integral time is divided into short time segment, and two integrators are used to integrate by turn. The whole integral signal can be obtained by adding two integrators’ output continuously. Controlled by CPLD, the alternant integrator’s drift is about 10mV in 400s, which can satisfy the experiment on EAST tokamak.

A hybrid digital-analog long-time integrator based on digital signal processing

DU Xiao-ying, JI Zhen-shan, WANG Yong

2009, 29(3): 279-283.

Asbtract ( )

PDF (1469KB) ( )

References | Related Articles | Metrics

A hybrid long-time intelligent based on digital signal processing was designed and developed. To compute the drift’s slope of the integrator in certain time t by using DSP, the drift value is obtained, so the drift can be decreased. The results of experiment on EAST tokamak show that this integrator without drift can be used in measuring of diagnostic signal reliably on tokamak.

Diagnosis of flow field generated by a solid operation material plasma generator

LIU Lei, CAO Jin-xiang, NIU Tian-ye, LIU Xin, YUAN Lei, WU Run-hui, N Ai-min, MENG Gang

2009, 29(3): 284-288.

Asbtract ( )

PDF (1612KB) ( )

References | Related Articles | Metrics

Langmuir probe array and spectroscopy are employed to diagnose the plasma jet generated from a solid operation material plasma generator. The generator can perform steadily for 300s with the input power at 2kW. In that case, the maximum inner temperature is 800K, the electron density of plasma jet varies in the range of 10¹¹～10¹²cm^–3, and the electron temperature varies in the range of 1.5～3.5eV, respectively.

Table of Content