电工技术学报2017，Vol.32Issue(8)：82-94,13.
基于激光诱导荧光法诊断大气压低温等离子体射流中OH自由基和O原子的时空分布
Laser Induced Fluorescence Diagnostics of the Temporal and Spatial Distribution of OH Radicals and O Atom in a Low Temperature Plasma Jet at Atmospheric Pressure
摘要
Abstract
The method of traditional optical emission spectroscopy is not suitable for the quantitative measurements of the density of OH radical and O atom in low temperature plasma jets at atmospheric pressure.Thus,this paper applied the single-photon laser induced fluorescence (LIF) and two-photon absorption laser induced fluorescence (TALIF).The plasma jet with needle-cylinder electrode structure was excited by nanosecond pulsed power supply.①OH radical and O atom in the plasma jet have a lifetime of 1 ms and 3ms,respectively.They are much longer than the duration time of pulse discharge.②By fitting the decay curve of fluorescence intensity of OH radical vs time,the absolute density of OH radical is estimated to be 1012～1013cm-3.③The densities of both active species decrease monotonically with the increase of the axial distance along the jet.However,it's surprising to observe that there are still a large amount of active species at even several cm far away from the jet nozzle.④The increased excitation frequency and pulse voltage result in the increased density of active species.Moreover,with the increase of the concentration of H2O impurities in helium gas,OH radical density decreases after reaching a maximum value at 2.7×1013cm-3 for H2O concentration of 120 ppm.The behavior of O atom density shows the same tendency with the increase of O2 percentage in helium.The inflection point corresponding to the peak density of O atom occurs at the O2 percentage of 0.5％.This study provides an important scientific basis for regulation and optimization of the densities of OH radicals and O atom in low temperature plasma jets.关键词
大气压低温等离子体射流/激光诱导荧光/活性粒子/等离子体医学/OH自由基/O原子/等离子体活性Key words
Atmospheric-pressure low-temperature plasma jets/laser induced fluorescence/active species/plasma medicine/OH radicals/O atom/plasma activity分类
信息技术与安全科学引用本文复制引用
吴淑群,董熙,裴学凯,岳远富,卢新培..基于激光诱导荧光法诊断大气压低温等离子体射流中OH自由基和O原子的时空分布[J].电工技术学报,2017,32(8):82-94,13.基金项目
国家自然科学基金(51077063、51607090),江苏省自然科学基金(BK20160796)和校人才引进基金(90YAH15059)资助项目. （51077063、51607090）
