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Electron cyclotron current drive (ECCD) will be applied in the EAST tokamak during its the new campaign. In order to provide theoretical predictions for relevant physical experiments, some numerical simulations of ECCD with the parameters of EAST have been can'ied out by using TORAY-GA code based on the understanding of ECCD mechanisms. ECCD efficiencies achieved in different plasma and electron cyclotron (EC) wave parameters are given. The dependences of ECCD characteristics on EC wave injection angle, toroidal magnetic field, plasma density, and temperature are presented and discussed. 相似文献
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采用蒙特-卡罗(Monte Carlo)模拟方法,研究了初始溅射粒子密度对其传输中的密度和速度分布以及环境气体密度分布的影响.结果表明,随着初始溅射粒子密度增大,烧蚀粒子和环境气体高密度峰的交叠区离开靶的最大距离减小,被衬底反弹后,距靶的最小距离减小,烧蚀粒子的速度分布随初始溅射粒子密度增大而变宽,当初始溅射粒子密度大于8.33×1025 m-3时,出现速度劈裂现象.所得结论为进一步定量研究纳米晶粒的成核机理提供了基础.
关键词:
Monte Carlo模拟
烧蚀粒子
密度分布
速度分布 相似文献
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以丝阵内爆零维模型为基础,采用Pspice模拟行为建模方法,建立了丝阵内爆动态电感与Z箍缩驱动器耦合的全电路模型,实现驱动器放电过程与丝阵内爆过程的自洽求解,并研究了丝阵参数、电路参数对内爆过程的影响.结果表明:丝阵负载与驱动器存在强耦合关系,丝阵参数、电路参数对丝阵峰值箍缩电流、内爆时间、内爆动能影响很大;在驱动器参数不变,内爆时间不超过电路固有放电周期1/4的前提下,峰值箍缩电流、内爆时间、内爆动能随丝阵质量的增加而增大,内爆时间随丝阵初始半径的增加而增大;在丝阵参数不变时,随着驱动器等效电容的增大,内爆时间减小,丝阵内爆动能增大,但驱动器储能转化为内爆动能的效率却先增大后减小.对于特定的驱动器,优化的丝阵参数应使内爆过程充分利用驱动器固有放电周期的上升沿,使丝阵快速收缩的时间起点接近电路固有放电周期的四分之一,以获得最大的动能效率.
关键词:
Z箍缩驱动器
零维内爆模型
模拟行为建模
耦合特性 相似文献
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Sawtooth-like electron density oscillations under laser blow-off and lower hybrid current drive in HL-1M tokamak 下载免费PDF全文
By using of a six-channel HCN laser interferometer, the sawtooth-like density oscillations without being exhibited in the ohmic phase plasma have been observed during lower hybrid current drive (LHCD) discharges in the HL-1M device. There are often accompanied by injected impurity with laser blow-off. Analyses show that this kind of density sawtooth-like oscillation comes from the mutual effect of LHCD and impurity. An available mechanism is the loss of superthermal electrons by the magnetic perturbation, which is caused by the crash of the central accumulated impurities. 相似文献
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Optimized calculation of the synergy conditions between electron cyclotron current drive and lower hybrid current drive on EAST 下载免费PDF全文
The optimized synergy conditions between electron cyclotron current drive(ECCD) and lower hybrid current drive(LHCD) with normal parameters of the EAST tokamak are studied by using the C3PO/LUKE code based on the understanding of the synergy mechanisms so as to obtain a higher synergistic current and provide theoretical reference for the synergistic effect in the EAST experiment. The dependences of the synergistic effect on the parameters of two waves(lower hybrid wave(LHW) and electron cyclotron wave(ECW)), including the radial position of the power deposition, the power value of the LH and EC waves, and the parallel refractive indices of the LHW(N) are presented and discussed. 相似文献
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The effects of trapped electrons on off-axis lower hybrid current drive (LHCD) in tokamaks are studied, A computer code for solving the Fokker-Planck equation in a toroidal geometry is developed and employed. The code is suitable for various auxiliary heating and current drive schemes in tokamak plasmas. The influence of the resonance regime on the current drive efficiency as well as the influence of trapped particle fraction on the current drive efficiency are emphasized. It is shown that, as an electrostatic force, the lower hybrid wave causes some of the trapped electrons to be untrapped and lose their energy, which can cut the LHCD efficiency by about 30%. The ITER scaling law is also used to estimate the trapped electron effects.[第一段] 相似文献
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The image theory of wave electron optics is used to study the current density distribution of electron beam spots for high-resolution electron optical systems. Using the wave aberration concept and paraxial expansion of charge density, the space charge effect is taken into consideration by modification of paraxial rays and spherical aberration coefficient of the lens. The point spreading function is obtained by Fourier-Bessel transform of the optical transfer function considering the space charge and partial coherence of the electron source. 相似文献
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用NaI闪烁体探测器组成的逃逸电子诊断系统和CdTe半导体探测阵列组成的快电子轫致辐射诊断系统,研究了一定等离子体密度条件下低杂波功率和等离子体电流对逃逸产生的影响以及一定低杂波功率下等离子体密度对逃逸电子产生的不同作用效果。根据实验数据计算了HT-7装置等离子体中电子逃逸的阈值电场和一定放电条件下电子逃逸的阈值能量。 相似文献
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采用等效电路和零维分析方法,建立了双层丝阵Z箍缩内爆动力学的物理模型. 研究了内、外层丝阵电感分布及其变化对双层丝阵内爆动力学模式的决定性影响,结果表明丝阵的初始电感决定了初始电流分配,动态电感变化影响丝阵内爆的动力学过程. 提出由于电感的变化可能存在四种不同的双层丝阵内爆动力学模式. 针对“强光一号”装置Z箍缩双层丝阵负载参数进行计算分析,可以得到外层等离子体穿透内层先运动到芯的动力学模式,与其他低电流装置在实验上观察到的物理图像一致.
关键词:
Z箍缩内爆等离子体
双层丝阵负载
电感
动力学模式 相似文献
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在装置“S-300”上,通过测量真空磁绝缘传输线中电极间电子流轫致辐射和负载上的电流、电压等参数,研究了磁绝缘传输线中的电流损失特性。实验中使用了阻抗特性不同的3种负载,结果表明,磁绝缘传输线中的电流损失特性显著地取决于负载。当负载为丝阵靶时,电流损失出现在丝阵等离子体最大箍缩时刻,且其值不超过负载总电流的5%。 相似文献
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从粒子密度和粒子流密度出发,分析了几类相关的算符,讨论了它们的性质与相互关系;从具体的物理意义出发,明确了合适的粒子密度算符和粒子流密度算符的表达形式. 相似文献
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建立了表面波驱动等离子体天线装置,提出了一种等离子体天线表面电流指数分布模型,并利用该表面电流分布模型计算了天线的辐射方向图.研究结果表明,等离子体密度随轴向距离的增大呈指数衰减趋势.正常工作状态下表面波波矢虚部随等离子体密度的增大而下降,遵循与等离子体密度类似的指数衰减规律,但其实部则基本保持不变.等离子体天线的表面电流呈振幅指数衰减行波模式.利用该表面电流分布模型计算得到的辐射方向图呈现典型的8字形分布,与实验测量结果良好符合.当射频功率减小,等离子体天线辐射方向图宽化. 相似文献