共查询到20条相似文献,搜索用时 93 毫秒
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叙述了HL-1托卡马克装置激光汤姆逊散射仪的结构和特性,介绍了多道散射信号的获取和校准方法,给出了电子温度测量的例子及其实验误差。 相似文献
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硅漂移(SDD)阵列探测器X射线能谱测量诊断 总被引:1,自引:0,他引:1
采用最新的SDD探测器阵列测量HL-2A托卡马克等离子体软X射线(1~20keV)辐射的能谱,获得电子温度、Zeff、重金属杂质含量绝对值及其时、空分布。由于SDD探测器较之传统的Si(Li)探测器有体积小、计数率高(≥10^6/S),能量分辨和量子效率高,不需液氮冷却的特点,并采用高速ADC和海量缓存器,电子温度测量的时、空分辨能力接近汤姆逊散射和ECE等方法.而测量精确度、使用寿命、造价、抗干扰能力、适应性等方面优于后者.且信息获取量大,可获得多种等离子体参数而备受重视,是一种最先进的诊断手段。 相似文献
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用切用汤姆逊散射(TTS)测量了电子漂移速度(vd,c)分布,由此,确定了电流密度(j)分布,延伸到等离子体直径(2a)的60%,空间分六为a的12%,统计误差为-10%,是与基于模拟研究所预期的精确度一致,比较了两种分析方法,并发现它们是一致的,在有峰化的和空心的j分布的电子回旋加热放电中TTS的结果与新经典电阻率完全一致。 相似文献
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采用性能优越的15道硅漂移探测器(SDD)阵列,在EAST全超导托卡马克上建立了1套较为完善的软X射线能谱诊断系统,用以测量等离子体在软X射线辐射能段(1~20keV)的能谱。该诊断系统的观测范围基本覆盖了整个等离子体空间,因此,可满足EAST不同放电位形下电子温度测量的要求。利用该诊断系统,可获得时间分辨达50ms、空间分辨约为7cm的电子温度剖面。通过对比发现,由该诊断系统所得到的电子温度与其它电子温度诊断系统所测量的电子温度基本一致。此外,该诊断系统还可监测在软X射线能量范围内出现的一些金属杂质的特征线辐射。 相似文献
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采用光谱仪测量了等离子体点火器出口射流的发射光谱,利用玻尔兹曼曲线斜率法计算了射流的电子温度,并通过电离平衡方程计算了射流气体温度,获得点火器出口射流长度、射流速度、电子温度和射流温度随弧电流及进口氩气流量的变化规律。并分析了航空等离子体电弧射流中是否可使用电子温度来代替射流气体温度。实验表明:弧电流随着进口氩气流量的增大而减小;出口射流长度和速度随弧电流的增大而增大,随进口氩气流量的增大先增大后减小;出口电子温度、电子密度和射流温度随弧电流的增大而升高,随氩气流量的增大而降低。 相似文献
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在托卡马克等离子体中,相同的等离子体电流条件下,若在较低的等离子体密度条件下发生反常多普勒共振,将会导致逃逸电子快螺旋角散射(FPAS)的发生;若在较高的等离子体密度条件下发生反常多普勒共振,则会导致逃逸电子正常螺旋角散射(NPAS)的发生。通过研究FPAS和NPAS条件下的逃逸电子行为,发现FPAS和NPAS均可一定程度增加逃逸电子的螺旋角,增加逃逸电子的同步辐射损失,减小逃逸电子的能量;且NPAS和FPAS对逃逸电子的影响主要集中在高能部分,对低能逃逸电子的影响较小。 相似文献
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Thomson scattering diagnostic is important for measuring electron temperature and density profiles. To improve the signal-to-noise ratio, a silicon avalanche photodiode (APD) with high quantum efficiency, high sensitivity, and high gain up to 100 was adopted to measure the Thomson scattering spectrum. A preamplifier, which has low noise, high bandwidth, and high sensitivity, was designed with suitable transimpedance. Using AD8367 as the post-amplifier, good performance of the APD readout electronics have been obtained. A discussion is presented on the performance of the amplifier using a laser diode to simulate the Thomson scattering light. The test results indicate that the designed circuit has a high amplifying factor and fast rising edge. So reduction of the integral gate of the CAMAC ADC converter can improve the signal-to-noise ratio. 相似文献
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A visible light imaging Thomson scattering (VIS-TVTS) diagnostic system has been developed for the measurement of plasma electron temperature on the HT-7 tokamak. The system contains a Nd:YAG laser (A = 532 nm, repetition rate 10 Hz, total pulse duration ≈ 10 ns, pulse energy 〉 1.0 J), a grating spectrometer, an image intensifier (I.I.) lens coupled with an electron multiplying CCD (EMCCD) and a data acquisition and analysis system. In this paper, the measurement capability of the system is analyzed. In addition to the performance of the system, the capability of measuring plasma electron temperature has been proved. The profile of electron temperature is presented with a spatial resolution of about 0.96 cm (seven points) near the center of the plasma. 相似文献
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Mengmeng XU 《等离子体科学和技术》2022,24(6):64008
In addition to the magnetic confinement fusion plasma, Thomson scattering has been applied to measure electron density and temperature of low-temperature plasmas. Based on a linear magnetized plasma device, a set of Thomson scattering diagnostic system is designed to diagnose the plasma with ${n}_{{\rm{e}}}={10}^{18}{\unicode{x02013}}{10}^{19}\,{{\rm{m}}}^{-3}$ and ${T}_{{\rm{e}}}=2{\unicode{x02013}}5$ eV. Due to low plasma temperature and density, this diagnostic system needs high spectral resolution and collection efficiency to meet the requirements of electron velocity distribution function measurements. Through the bench test, it is confirmed that the spectral resolution reaches 0.01 nm, and theoretical collection efficiency is high enough to obtain a Thomson scattering spectrum by 1000 accumulations. 相似文献
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《Fusion Engineering and Design》2014,89(5):761-765
TJ-II Thomson Scattering diagnostic provides temperature and density profiles of plasma. The CCD camera acquires images that are corrupted with some kind of noise called stray-light. This noise degrades both image contrast and measurement accuracy, which could produce unreliable profiles of the diagnostic. So far, several approaches have been applied in order to decrease the noise in the TJ-II Thomson scattering images. Since the presence of the noise is not global but located in some particular regions of the image, advanced processing techniques are needed. However such methods require of manual fine-tuning of parameters to reach a good performance. In this contribution, an iterative image processing approach is applied in order to reduce the stray light effects in the images of the TJ-II Thomson scattering diagnostic. The proposed solution describes how the noise can be iteratively reduced in the images when a key parameter is automatically adjusted during the iterative process. 相似文献
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A multipulse Nd:YAG (Neodym-yttrium aluminium garnet) laser Thomson scattering diagnostic system developed was recently applied on HT-7 tokamak to obtain more accurate electron temperatures. A CAMAC-based real-time computer system for laser control, data acquisition, analysis and calibration was investigated in detail. Furthermore, the reliability and accuracy of this diagnostic system were demonstrated by comparing the results with those of a soft-X ray diagnostic system. 相似文献
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《核技术(英文版)》2021,32(4):20-29
A 2856-MHz,π-mode,seven-cell standingwave deflecting cavity was designed and fabricated for bunch length measurement in Tsinghua Thomson scattering X-ray source... 相似文献
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This article describes the data processing and acquisition system for the HT-7 multipulse Thomson scattering diagnostic. An eight-pulse laser is used in the Thomson scattering system to obtain electron temperature profiles at eight different times throughout an entire plasma discharge. The major components of the diagnostic system consist of a multipulse iNd-glass laser,a photodetector‘‘s subsystem, a calibration set and a CAMAC data processing and acquisition system. The data processing software along with LeCroy 2250L will perform the data acquisition.In order to simplify the operation and extend the capability of its compatibility with other math softwares, the processing software has been improved by the authors. The new software based on the VC easily utilizes some math softwares to calculate the electron temperature. The new software is simpler and more operational than the old one. 相似文献
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A CW CO2 laser collective Thomson scattering diagnostics was developed to measure plasma density fluctuations on the HT-7 tokamak. The design and construction of CO2 laser scattering apparatus is described. The laser source is a continuous-wave CO2 laser with a cavity length of 1.9 m and a power output of about 10 W at 10.6 μm. The k-resolution of the system is △k ≈ 3.2 cm^-1. The preliminary data from the diagnostic is presented. 相似文献
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HT-7 Multipoint Nd Laser Thomson Scattering Apparatus 总被引:1,自引:0,他引:1
1. IlltroductionThomson scattering diagnostic has been an important and standard method for measuring temperature and density profiles on all modern toka-maks, such as the TV Thotnson Scattering systemon TFTR [1], the LIDAR system on JET [2] and theNd:YAG laser Thomson scattering system on Dlll--D[3]. It has the attractive characteristics of not per-turbillg the plasma to be investigated and of derivingthe absolute values of electronic temperature Ti anddensity ne' From the knot'.led… 相似文献