本文選題：脈沖微放電等離子體 + 光譜分析　； 參考：《光譜學與光譜分析》2017年06期

【摘要】：利用大氣壓脈沖微放電剝蝕源對鋁合金進行光譜分析。該針板結(jié)構(gòu)微放電裝置具有價格低廉、操作便捷、分析快速等特點。脈沖放電能瞬間注入極大的放電能量,不致使樣品融化,進而保證放電的穩(wěn)定性。在幾微秒的時間內(nèi),對鎢針電極施加近-4 000V的高壓,電極間迅速形成放電通道,針尖和樣品之間形成高達20A的電流,造成對樣品的剝蝕,并對被剝蝕的粒子進行激發(fā)。單次放電脈沖注入能量約為8.5mJ,能量以電流的形式傳遞于放電電極。剝蝕形貌圖表明放電微等離子體局域在電極間隙,針尖軸向上的能量傳遞和電流密度遠高于離軸區(qū)域。為了深入研究剝蝕機制和物理性質(zhì),對等離子體源的電學特性進行了討論。通過精確的時序拍攝技術(shù)觀測了等離子體的演化過程,從ICCD相機的快速成像結(jié)果可以看到等離子體源壽命與脈沖高壓放電源的脈寬相當,發(fā)光強度與放電電流變化趨勢相吻合。與光譜分析裝置相連接,脈沖微放電剝蝕源可有效激發(fā)合金樣品中的鋁、鎂、錳、銅等元素原子譜線。對放電過程等離子體光譜特性進行考察,利用玻爾茲曼斜線法和Stark展寬法計算等離子體電子溫度和電子數(shù)密度,分別得到過程中等離子體電子激發(fā)溫度約6 700K,等離子體電子數(shù)密度約1017 cm-3量級,并驗證了放電處于局域熱平衡狀態(tài)。探究其定量分析性能,結(jié)果表明該脈沖微放電等離子體直接作為一種光譜分析源可實現(xiàn)對鋁合金樣品快速定量分析。
[Abstract]:The spectrum analysis of aluminum alloy was carried out by using atmospheric pressure pulse microdischarge denudation source. The device has the advantages of low price, convenient operation and fast analysis. Pulse discharge can inject a great deal of discharge energy in an instant, which does not cause the sample to melt, thus ensuring the stability of the discharge. Within a few microseconds, the tungsten needle electrode was subjected to a high voltage of -4000 V, and a discharge channel was formed rapidly between the electrodes, and a current of up to 20A was formed between the tip of the needle and the sample, resulting in the denudation of the sample and the excitation of the denudated particles. The single discharge pulse injection energy is about 8.5 mJ, and the energy is transferred to the discharge electrode in the form of current. The denudation topography shows that the energy transfer and current density of the discharge microplasma are much higher than those in the off-axis region in the gap between the electrodes and the axial direction of the tip. In order to study the denudation mechanism and physical properties, the electrical properties of the plasma source are discussed. The evolution process of plasma was observed by precise time sequence shooting technique. From the fast imaging results of ICCD camera, it can be seen that the lifetime of plasma source is equal to the pulse width of pulse high voltage discharge power supply, and the intensity of luminescence is consistent with the trend of discharge current. Connected with the spectrometer, the pulsed micro-discharge denudation source can effectively excite the atomic lines of Al, mg, mn and Cu in the alloy samples. The plasma spectral characteristics during discharge were investigated. The plasma electron temperature and electron number density were calculated by Boltzmann slant method and Stark broadening method. The plasma electron excitation temperature is about 6 700 K and the plasma electron number density is about 1017 cm-3. It is verified that the discharge is in a local thermal equilibrium state. The results show that the pulsed micro-discharge plasma can be used as a direct source of spectral analysis for rapid quantitative analysis of aluminum alloy samples.
【作者單位】： 廈門大學化學化工學院譜學分析與儀器教育部重點實驗室;
【基金】：國家重大科研儀器研制項目(21427813) 國家基礎(chǔ)科學人才培養(yǎng)基金項目(J1310024)資助
【分類號】：TG115.33
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本文編號：1780857