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不同样品温度下聚焦透镜到样品表面距离对激光诱导铜击穿光谱的影响 预览
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作者 杨雪 李苏宇 +2 位作者 姜远飞 陈安民 金明星 《物理学报》 SCIE EI CAS CSCD 北大核心 2019年第6期174-182,共9页
研究了不同温度下聚焦透镜到样品表面距离对激光诱导击穿光谱(laser-induced breakdown spectroscopy,LIBS)强度的影响,使用Nd:YAG脉冲激光激发样品并产生等离子体,探测的等离子体发射的光谱线为Cu(Ⅰ)510.55 nm,Cu(Ⅰ)515.32 nm和Cu(Ⅰ... 研究了不同温度下聚焦透镜到样品表面距离对激光诱导击穿光谱(laser-induced breakdown spectroscopy,LIBS)强度的影响,使用Nd:YAG脉冲激光激发样品并产生等离子体,探测的等离子体发射的光谱线为Cu(Ⅰ)510.55 nm,Cu(Ⅰ)515.32 nm和Cu(Ⅰ)521.82 nm.使用透镜的焦距为200 mm,测量的聚焦透镜到样品表面距离的范围为170—200 mm,样品温度从25℃升高到270℃,激光能量为26 mJ.总体上,升高样品温度能有效地提高LIBS光谱的辐射强度.在25℃和100℃时,光谱强度随着聚焦透镜到样品表面距离的增加而单调增加;在样品温度更高(150, 200, 250和270℃)时,光谱强度随着距离的增加出现先升高而后又降低的变化.同时,在样品接近焦点附近,随着样品温度的升高,LIBS光谱强度的变化不明显,还可能出现光谱强度随着样品温度升高而降低的情况,这在通过升高样品温度来提高LIBS光谱强度中特别值得我们注意.为了更进一步了解这两个条件对LIBS的影响,计算了等离子体温度和电子密度,发现等离子体温度和电子密度的变化与光谱强度的变化几乎一致,更高样品温度下产生的等离子体温度和电子密度更高. 展开更多
关键词 激光诱导击穿光谱 样品温度 聚焦透镜到样品表面距离 等离子体温度和电子密度
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双谱线内标对激光诱导击穿光谱稳定性的改善 预览 被引量:6
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作者 刘莉 《激光技术》 CAS CSCD 北大核心 2015年第1期90-95,共6页
为了改善激光诱导击穿光谱稳定性,提出了一种双谱线内标算法,采用分析谱线强度与两条内标谱线强度之和归一化的方式提高分析光谱的稳定性。以钢铁中的硅元素谱线Si I288.16nm为例,对算法进行了数值计算和模拟,最后以锰和铜谱线为... 为了改善激光诱导击穿光谱稳定性,提出了一种双谱线内标算法,采用分析谱线强度与两条内标谱线强度之和归一化的方式提高分析光谱的稳定性。以钢铁中的硅元素谱线Si I288.16nm为例,对算法进行了数值计算和模拟,最后以锰和铜谱线为例对算法的普遍性进行了验证。结果表明,在激光诱导等离子典型温度和电子数密度区域,采用双谱线内标算法比普通内标法能更有效地改善分析谱线的稳定性。 展开更多
关键词 激光技术 激光诱导击穿光谱 双谱线内标算法 等离子体温度和电子密度
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Spectroscopic Studies of the Laser Produced Lead Plasma
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作者 M. HANIF M. SALIK M. A. BAIG 《等离子体科学和技术:英文版》 SCIE EI CAS CSCD 2011年第2期129-134,共6页
<正> 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 ion... <正> 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. 展开更多
关键词 激光光谱学 铅离子 脉冲ND:YAG激光 32纳米 中性原子 激发温度 电子数密度 二次谐波
Time-Resolved Emission Spectroscopic Study of Laser-Induced Steel Plasmas
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作者 M.L.SHAH A.K.PULHANI +1 位作者 B.M.SURI G.P.GUPTA 《等离子体科学和技术:英文版》 SCIE EI CAS CSCD 2013年第6期546-551,共6页
<正>Laser-induced steel plasma is generated by focusing a Q-switched Nd:YAG visible laser(532 nm wavelength) with an irradiance of 1 x 109 W/cm2 on a steel sample in air at atmospheric pressure.An Echelle spectr... <正>Laser-induced steel plasma is generated by focusing a Q-switched Nd:YAG visible laser(532 nm wavelength) with an irradiance of 1 x 109 W/cm2 on a steel sample in air at atmospheric pressure.An Echelle spectrograph coupled with a gateable intensified charge-coupled detector is used to record the plasma emissions.Using time-resolved spectroscopic measurements of the plasma emissions,the temperature and electron number density of the steel plasma are determined for many times of the detector delay.The validity of the assumption by the spectroscopic methods that the laser-induced plasma(LIP) is optically thin and is also in local thermodynamic equilibrium(LTE) has been evaluated for many delay times.From the temporal evolution of the intensity ratio of two Fe I lines and matching it with its theoretical value,the delay times where the plasma is optically thin and is also in LTE are found to be 800 ns,900 ns and 1000 ns. 展开更多
关键词 等离子体发射光谱 激光诱导等离子体 时间分辨 钢铁 电荷耦合检测器 Nd YAG激光 局部热力学平衡 等离子体聚焦
Langmuir Probe Measurements of an Expanding Argon Plasma
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作者 曹小岗 夏玉玺 +10 位作者 陈炳周 田树平 王春玲 杨党校 薛晓艳 张卫卫 王建强 苟富均 朱自川 欧巍 陈顺礼 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2015年第1期20-24,共5页
In this work,we studied the effects of the discharge current,gas flow rate and vessel pressure on the electron temperature and density of Ar plasma by Langmuir probe measurement.The argon plasma was created by a one-c... In this work,we studied the effects of the discharge current,gas flow rate and vessel pressure on the electron temperature and density of Ar plasma by Langmuir probe measurement.The argon plasma was created by a one-cathode arc source.The experimental results show that with increasing discharge current and gas flow rate,the electron temperature and density increase.It is found that when the discharge current is 70 A,90 A and HO A at an argon flow rate of2000 seem,the electron densities at about 0.186 m distance from the nozzle are 13.00×1018 m-3,14.04×1018 m-3 and 15.62×1018 m-3,and the electron temperatures are 0.38 eV,0.58 eV and0.71 eV,respectively.The positive I-V characteristic is explained. 展开更多
关键词 氩等离子体 朗缪尔探针 测量 电子温度 放电电流 Ar等离子体 电子密度 气体流量
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