We report spectroscopic studies on plasma electron number density of laser-induced plasma produced by ns-Nd:YAG laser light pulses on an aluminum sample in air at atmospheric pressure. The effect of different laser e...We report spectroscopic studies on plasma electron number density of laser-induced plasma produced by ns-Nd:YAG laser light pulses on an aluminum sample in air at atmospheric pressure. The effect of different laser energy and the effect of different laser wavelengths were compared. The experimentally observed line profiles of neutral aluminum have been used to extract the excitation temperature using the Boltzmann plot method, whereas the electron number density has been determined from the Stark broadened as well as using the Saha-Boltzmann equation (SBE). Each approach was also carried out by using the AI emission line and Mg emission lines. It was observed that the,SBE method generated a little higher electron number density value than the Stark broadening, method, but within the experimental uncertainty range. Comparisons of Ne determined by the two methods show the presence of a linear relation which is independent of laser energy or laser wavelength. These results show the applicability of the SBE method for Are determination, especially when the system does not have any pure emission lines whose electron impact factor is known, Also use of Mg lines gives superior results than Al lines.展开更多
Emission spectra of a semiconductor bridge (SCB) plasma in a visible range was studied in air. The electron density was measured in a conventional way from the broadening of the Al Ⅰ 394.4 nm Stark width. Based on ...Emission spectra of a semiconductor bridge (SCB) plasma in a visible range was studied in air. The electron density was measured in a conventional way from the broadening of the Al Ⅰ 394.4 nm Stark width. Based on the Saha equation, a system for recording the intensity of Si Ⅰ 390.5 nm and Si Ⅱ 413.1 nm was designed. With this technique, the SCB plasma electron density was measured well and accurately. Moreover, the electron density distribution Vs time was acquired from one SCB discharge. The individual result from the broadening of the Al Ⅰ 394.4 nm Stark width and Saha equation was all in the range of 1015 cm^-3 to 1016 cm^-3. Finally the presumption of the local thermodynamic equilibrium (LTE) condition was validated.展开更多
本文对SCB等离子体发射光谱进行了试验研究,在局部热力学平衡条件下,用Al I 394.40nm谱线Stark的展宽法测量了SCB等离子体的电子密度;在发射光谱和Saha方程理论的基础上,设计并建立一套测试仪器,时间分辨率为0.1μs,将其测量的电子密度...本文对SCB等离子体发射光谱进行了试验研究,在局部热力学平衡条件下,用Al I 394.40nm谱线Stark的展宽法测量了SCB等离子体的电子密度;在发射光谱和Saha方程理论的基础上,设计并建立一套测试仪器,时间分辨率为0.1μs,将其测量的电子密度与同种试验条件下的Stark展宽法得到的结果相比较,电子密度的数量级都为10^(15)cm^(-3)~10^(16)cm^(-3),且随时间的变化的规律相同.展开更多
基于介质阻挡放电工作原理,设计了气体-液体两相放电装置。采用发射光谱诊断技术,结合Stark展宽理论,系统研究了工作电压、气体流量、液体高度等参数对气体-液体两相放电发射光谱及电子密度的影响规律。结果表明,氢氦混合气-生物油两相...基于介质阻挡放电工作原理,设计了气体-液体两相放电装置。采用发射光谱诊断技术,结合Stark展宽理论,系统研究了工作电压、气体流量、液体高度等参数对气体-液体两相放电发射光谱及电子密度的影响规律。结果表明,氢氦混合气-生物油两相界面放电时,氢发射光谱特征谱线Hα强度最高,而巴耳末系的另外三条特征谱线未检出,放电低温等离子体的电子能量介于12.09-12.75 e V间;氢发射光谱α特征峰强度和电子密度随工作电压的增加而增加,随气体流量、液体高度的增加而减小。展开更多
文摘We report spectroscopic studies on plasma electron number density of laser-induced plasma produced by ns-Nd:YAG laser light pulses on an aluminum sample in air at atmospheric pressure. The effect of different laser energy and the effect of different laser wavelengths were compared. The experimentally observed line profiles of neutral aluminum have been used to extract the excitation temperature using the Boltzmann plot method, whereas the electron number density has been determined from the Stark broadened as well as using the Saha-Boltzmann equation (SBE). Each approach was also carried out by using the AI emission line and Mg emission lines. It was observed that the,SBE method generated a little higher electron number density value than the Stark broadening, method, but within the experimental uncertainty range. Comparisons of Ne determined by the two methods show the presence of a linear relation which is independent of laser energy or laser wavelength. These results show the applicability of the SBE method for Are determination, especially when the system does not have any pure emission lines whose electron impact factor is known, Also use of Mg lines gives superior results than Al lines.
基金supported by National Major Base Projects of China
文摘Emission spectra of a semiconductor bridge (SCB) plasma in a visible range was studied in air. The electron density was measured in a conventional way from the broadening of the Al Ⅰ 394.4 nm Stark width. Based on the Saha equation, a system for recording the intensity of Si Ⅰ 390.5 nm and Si Ⅱ 413.1 nm was designed. With this technique, the SCB plasma electron density was measured well and accurately. Moreover, the electron density distribution Vs time was acquired from one SCB discharge. The individual result from the broadening of the Al Ⅰ 394.4 nm Stark width and Saha equation was all in the range of 1015 cm^-3 to 1016 cm^-3. Finally the presumption of the local thermodynamic equilibrium (LTE) condition was validated.
文摘本文对SCB等离子体发射光谱进行了试验研究,在局部热力学平衡条件下,用Al I 394.40nm谱线Stark的展宽法测量了SCB等离子体的电子密度;在发射光谱和Saha方程理论的基础上,设计并建立一套测试仪器,时间分辨率为0.1μs,将其测量的电子密度与同种试验条件下的Stark展宽法得到的结果相比较,电子密度的数量级都为10^(15)cm^(-3)~10^(16)cm^(-3),且随时间的变化的规律相同.
文摘基于介质阻挡放电工作原理,设计了气体-液体两相放电装置。采用发射光谱诊断技术,结合Stark展宽理论,系统研究了工作电压、气体流量、液体高度等参数对气体-液体两相放电发射光谱及电子密度的影响规律。结果表明,氢氦混合气-生物油两相界面放电时,氢发射光谱特征谱线Hα强度最高,而巴耳末系的另外三条特征谱线未检出,放电低温等离子体的电子能量介于12.09-12.75 e V间;氢发射光谱α特征峰强度和电子密度随工作电压的增加而增加,随气体流量、液体高度的增加而减小。