摘要:Plasma Science and Technology (PST) is a journal reporting novel experimental and theoretical results and progress of interdisciplinary and application sciences in the field to Plasma Physics.
摘要:Spectroscopic emission of lead plasma, generated by the fundamental (1064 nm) andsecond harmonics (532 nm) of a Q-switched pulsed Nd: YAG laser, is studied. The spectral lines ofneutral atoms and singly ionized lead ions were shown predominantly. The profiles of neutral leadlines observed were used to extract the excitation temperature using Boltzmann plots, whereaselectron number density was determined from the profile of Stark broadened line. The variationsof excitation temperature and electron number density as a function of laser energy were studied.
摘要:Stability of the kinetic Alfven wave in a plasma of hydrogen, oxygen and electronsis studied. Each species is modeled by drifting ring distributions in the direction parallel to themagnetic field, while in the perpendicular direction the distribution is simulated with a loss conetype distribution obtained through the subtraction of two Maxwellian distributions with differenttemperatures. It is found that for frequencies ω* < ωch with ω* and ωch the Doppler shifted andhydrogen ion gyro-frequencies, respectively, the growth rate of the kinetic Alfven wave increaseswith the increase in propagation angles and density of oxygen ions. On the other hand, forfrequencies ω* < ωcO with ωcO the oxygen ion gyro-frequency the growth rate is independent ofthe oxygen ion density.
摘要:Radial profiles of impurity ions of carbon, neon and iron were measured for hightemperatureplasmas in large helical device (LHD) using a space-resolved extreme ultraviolet(EUV) spectrometer in the wavelength range of 60 A to 400 A. The radial positions of the impurityions obtained are compared with the local ionization energies, E_1 of these impurity ions and theelectron temperatures T_(ez) there. The impurity ions with 0.3 keV ≤ E_i≤ 1.0 keV are alwayslocated in outer region of plasma, i.e., 0.7≤ p≤ 1.0, and those with E_i <0.3 keV are located inthe ergodic layer, i.e., 1.0 ≤ p ≤ 1.1, with a sharp peak edge, where p is the normalized radialposition. It is newly found that T_(ez) is approximately equal to E_i for the impurity ions withE_i≤ 0.3 keV, whereas roughly half the value of E_i for the impurity ions with 0.3 keV ≤ E_i ≤1.0 keV. It is known that T_(ez) is considerably lower than E_i in the plasma edge and approachesto E_i in the plasma core. Therefore, this result seems to originate from the difference in thetransverse transport between the plasma edge at p ≤1.0 and the ergodic layer at p ≥ 1.0. Thetransverse transport is studied with an impurity transport simulation code. The result revealedthat the difference appearing in the impurity radial positions can be qualitatively explained bythe different values of diffusion coefficient, e.g., D = 0.2 m^2/s and 1.0 m^2/s, which can be takenas a typical index of the transverse transport.
摘要:A new method, by using eigenmodes to reduce the fitting parameters and precalculatededdy current based on a lump parameter circuit equation, is applied to reconstruct thevacuum field for EAST plasma startup.
摘要:Magnetohydrodynamic(MHD)n=l kink mode with n the toroidal mode number isstudied and the operational beta limit,constrained by the mode,is calculated for the equilibrium ofHL-2A by using the GATO code.Approximately the same beta limit is obtained for configurationswith a value of the axial safety factor qo both larger and less than 1.Without the stabilization ofthe conducting wall,the beta limit is found to be 0.821% corresponding to a normalized beta valueof β_N^c=2.56 for a typical HL-2A discharge with a plasma current Ip=0.245 MA,and the scaling ofβ_N^c~constant is confirmed.
摘要:Reconstruction of experimental axisymmetric equilibria is an important part of toka-mak data analysis.Fourier expansion is applied to reconstruct the vessel current distribution inEFIT code.Benchmarking and testing calculations are performed to evaluate and validate thisalgorithm.Two cases for circular and non-circular plasma discharges are presented.Fourier ex-pansion used to fit the eddy current is a robust method and the real time EFIT can be introducedto the plasma control system in the coming campaign.
摘要:Plasma Science and Technology (PST) is a journal reporting novel experimental and theoretical results and progress of interdisciplinary and application sciences in the field to Plasma Physics.
摘要:Experimental progress of lower hybrid current drive(LHCD)and ion Bernsteinwave(IBW)heating was achieved significantly in HT-7.Long pulse plasmas,up to 400 s,wereobtained by LHCD.High power lower hybrid wave(LHW),with P_(lhw)of 800 kW at 2.45 GHz,was launched and the current drive efficiency was studied for different wave powers.Electrontemperature and Z_(eff)were measured in LHCD discharges.Heating experiment and recent resultsof high power ion Bernstein wave,with P_(ibw)of 600 kW at 27 MHz,were summarized.
摘要: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 为更全体的血浆花托的光线的平衡的 v 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。
摘要:水动力学(MHD ) 挥动的磁电机的 Stabilization/destabilization 以波浪精力被提出,在波浪服从于 Alfv é n 和健全回声的地方并且也在传导性的墙由小抵抗力影响了。否定精力波浪,可以面对吝啬的流动存在,被显示被抵抗的墙使动摇,在它的生长率被精力驱散率描绘的地方。回声的效果为 Alfv é n 和健全连续统模式基于波浪精力的最近的知识也被检验。在 eigenmode 和有精力的一样的符号的一个连续统模式之间的反响的联合导致阶段混合(或连续统) 抑制。相反,如果他们的符号是相反的,如此的回声触发不稳定性。
摘要:Plasma Science and Technology (PST) is a journal reporting novel experimental and theoretical results and progress of interdisciplinary and application sciences in the field to Plasma Physics.
摘要:A hydrodynamic approach is used to investigate a three-component magnetized plasma sheath which consists of electrons and two species of positive ions.Assuming a phase space of one-dimensional spatial coordinate system and three-dimensional velocity coordinate system, the effect of different concentrations of positive ion species on some characteristics of the plasma sheath such as the velocity and density distribution of positive ion species and the electrostatic potential of this region is investigated.The calculated results show that the increase in the density ratio of positive ion species causes a decrease in both the ion velocities and the electrostatic potential of the sheath region.Also,it is shown that in the sheath region of a magnetized plasma consisting of only one positive ion species the bumps of the net density of charged particles disappears much faster.In addition,three-dimensional velocity of each positive ion species in the sheath region is plotted for different concentrations of positive ion species.