本文選題：激光誘導(dǎo)擊穿光譜 + 聚變等離子體裝置　； 參考：《大連理工大學(xué)》2015年博士論文

【摘要】：在托卡馬克運(yùn)行過程中,面對等離子體材料(Plasma-Facing Material, PFM)會受到來自芯部等離子體的穩(wěn)態(tài)/瞬態(tài)熱流和粒子流的沖擊,發(fā)生一系列等離子體與壁材料相互作用(Plasma Wall Interaction, PWI)過程,導(dǎo)致燃料滯留、雜質(zhì)產(chǎn)生、起泡、共沉積等問題。而能否解決這些問題,是決定未來ITER (International Thermonuclear Experimental Reactor)計(jì)劃成功與否最為關(guān)鍵的因素之一。直線等離子體裝置可以產(chǎn)生具有托卡馬克邊緣等離子體參數(shù)的穩(wěn)態(tài)/瞬態(tài)等離子體束流,用其產(chǎn)生的等離子體束轟擊PFM樣品,可以模擬研究托卡馬克PWI過程,是進(jìn)行PWI模擬實(shí)驗(yàn)研究的主要途徑。然而受到診斷手段的制約,PWI的原位診斷研究具有相當(dāng)大的挑戰(zhàn)。因此,發(fā)展PFM元素成分原位診斷技術(shù)用于直線等離子體裝置以及托卡馬克裝置是急需解決的關(guān)鍵問題之一。PFM表面的元素成分的實(shí)時原位的獲得,對理解PWI過程、揭示PWI機(jī)理、提出PFM優(yōu)化方案具有非常重要的意義。針對上述問題,本論文發(fā)展了激光誘導(dǎo)擊穿光譜(Laser-Induced Breakdown Spectroscopy, LIB S)原位壁診斷技術(shù),用于直線等離子體裝置Magnum-PSI、 DUT-PSI以及托卡馬克聚變裝置EAST(Experimental Advanced Superconducting Tokamak)中PFM樣品元素成分的原位診斷,并研究了PWI過程中的燃料滯留、雜質(zhì)產(chǎn)生、鋰化共沉積等關(guān)鍵科學(xué)問題。具體內(nèi)容如下：在第二章中,介紹了在Magnum-PS I直線等離子體裝置上建立的LIBS原位PFM診斷系統(tǒng),可在10-7 mbar背景氣壓下,獲得PFM元素高時空分辨LIBS光譜信號。該套LIBS系統(tǒng)的成功建立是國際上首次將LIBS用于大型直線等離子體實(shí)驗(yàn)裝置。利用Magnum-PSI裝置產(chǎn)生的高通量氘等離子體(1024 m-2s-1),結(jié)合原位LIBS 技術(shù),研究了不同劑量氘等離子體輻照后的純鎢、鋰化鎢、原始石墨瓦、鋰化石墨瓦的氘滯留和元素分布性質(zhì),發(fā)現(xiàn)鋰對鎢表面起泡具有明顯的抑制作用。實(shí)驗(yàn)表明,在1.9 1025m-2劑量的氘等離子體輻照下,鋰化鎢中氘的信號強(qiáng)度明顯高于純鎢材料中氘的信號強(qiáng)度,這主要是由鋰與氘的化學(xué)反應(yīng)導(dǎo)致的強(qiáng)烈的化學(xué)吸附造成的；隨著氘等離子體輻照劑量增加至6.210 25 m-2,純鎢和鋰化鎢的樣品都出現(xiàn)明顯的氘滯留飽和現(xiàn)象。LIBS深度分析結(jié)果表明,鋰、氘、氫信號隨深度的增加而降低,鎢信號隨深度先加強(qiáng)后達(dá)到穩(wěn)定值；氘等離子體輻照可使鋰再沉積過程與濺射過程達(dá)到平衡。X射線光電子能譜(X-ray Photoelectron Spectroscopy, XPS)離線分析結(jié)果表明,LIBS與XPS獲得的各元素的分布結(jié)果一致。通過對鋰化鎢樣品的LIBS激光燒蝕坑的分析,發(fā)現(xiàn)激光燒蝕后,氘等離子體輻照使鋰發(fā)生了顯著的再沉積現(xiàn)象。在第三章中,介紹了低氣壓直流級聯(lián)弧等離子體束裝置(DUT-PSI)的建立；利用發(fā)射光譜二維等離子體參數(shù)診斷系統(tǒng),對氬/氮激波狀態(tài)等離子體束激波區(qū)的發(fā)光強(qiáng)度、電子溫度、振動溫度和轉(zhuǎn)動溫度同時進(jìn)行了測量。結(jié)果表明,在激波狀態(tài)等離子體的壓縮區(qū),等離子體發(fā)光強(qiáng)度較高、電子溫度較低、振動溫度和轉(zhuǎn)動溫度較高。各溫度具有明顯的差異,說明低氣壓等離子體束處于顯著的非平衡狀態(tài)。經(jīng)過對DUT-PSI電極結(jié)構(gòu)優(yōu)化升級后,該裝置可產(chǎn)生具有類偏濾器區(qū)域等離子體參數(shù)的低溫高密度等離子體束,電子溫度為1-1.2 eV、電子密度可達(dá)210 14 cm-3,可用于模擬研究鎢的鋰化等PWI相關(guān)過程。結(jié)合原位LIBS元素化學(xué)成像系統(tǒng),研究了鋰化鎢材料及其雜質(zhì)元素在樣品表面三維分布特性。研究表明鋰化鎢樣品表面的鋰、氫、氧和氬元素分布具有相似的趨勢,在鋰信號強(qiáng)度高的區(qū)域,氫、氧、氬元素的信號強(qiáng)度也高,但與其它元素如鎢的分布不同。通過離線XPS能譜分析,佐證了LIBS化學(xué)成像的分析結(jié)果,并對激光燒蝕區(qū)、鋰化鎢表面等不同位置的元素化學(xué)態(tài)進(jìn)行了分析。在第四章中,通過對2012年EAST實(shí)驗(yàn)周期的偏濾器石墨瓦(該瓦共經(jīng)歷了5621次放電,總放電時間超過50000 s)進(jìn)行離線LIBS分析,發(fā)現(xiàn)氘在EAST偏濾器石墨瓦上的滯留主要是通過鋰-氘共沉積層引起的。氘的滯留比例(D/(D+H))隨著深度先增加,隨后穩(wěn)定在0.17左右,該值可以反映出EAST放電時在該偏濾器瓦處的氘滯留比例。針對EAST內(nèi)的低氣壓真空環(huán)境,研究了LIBS等離子體收集區(qū)域?qū)IBS信號采集的影響。對碳、硅、鉬等常見PFM樣品元素進(jìn)行空間分辨LIBS分析,發(fā)現(xiàn)由于脈沖激光燒蝕等離子體的軔致輻射、復(fù)合以及真空環(huán)境下等離子體超聲膨脹過程,碳、硅、鉬的信號強(qiáng)度從激光燒蝕等離子體的中心到邊緣先升高后下降,并研究了激光光斑尺寸和能量對LIBS信號的影響。本章另一部分重點(diǎn)論述了如何在EAST托卡馬克上建立原位LIBS壁診斷系統(tǒng)。通過合理利用兩個預(yù)留法蘭接口、優(yōu)化光路設(shè)計(jì),實(shí)現(xiàn)了國際上首次將LIBS技術(shù)與具有偏濾器位型的全超導(dǎo)托卡馬克相結(jié)合,可對EAST高場側(cè)中平面1212cm2范圍的第一壁進(jìn)行三維LIBS元素分析。在2014年EAST實(shí)驗(yàn)周期中,使用LIBS實(shí)現(xiàn)了對壁表面元素變化的原位測量,成功獲得了EAST壁表面的鋰、鉬、氘、氫、鎢、鑭、鈦、硅、鈉等元素信號；測定EAST在經(jīng)過兩次45 g的鋰坩堝蒸發(fā)壁處理、鋰彈丸注入實(shí)驗(yàn)以及194炮放電后,鋰沉積層的厚度從4.0 μm增加到了9.0 μm；并獲得了鉬第一壁上的氘滯留比例(D/(H+D))在61%-64%之間。
[Abstract]:During the operation of Tokamak, the plasma material (Plasma-Facing Material, PFM) will be subjected to the steady / transient heat flow from the core plasma and the impact of the particle flow. A series of plasma interactions with the wall materials (Plasma Wall Interaction, PWI) process lead to the retention of fuel, the formation of impurities, the foaming, and the co deposition. It is one of the most important factors to determine whether the future ITER (International Thermonuclear Experimental Reactor) plan is successful or not. The linear plasma device can produce a steady / transient plasma beam with the plasma parameters of the tokamak edge plasma, which is produced by the plasma beam. The bombardment of PFM samples can simulate the PWI process in Tokamak, which is the main approach to the study of PWI simulation experiments. However, under the restriction of the diagnostic means, the study of the in-situ diagnosis of PWI has considerable challenges. Therefore, it is urgently needed to develop the PFM element in situ diagnosis technology for the linear plasma device and the Tokamak device. The real time in situ acquisition of element components on.PFM surface, one of the key problems, is very important for understanding the PWI process, revealing the PWI mechanism and putting forward the PFM optimization scheme. In this paper, the laser induced breakdown spectroscopy (Laser-Induced Breakdown Spectroscopy, LIB S) in situ wall diagnosis technology is developed for the straight line. Plasma devices Magnum-PSI, DUT-PSI and the in situ diagnosis of the elements of PFM samples in EAST (Experimental Advanced Superconducting Tokamak) in the Tokamak fusion device, and the key scientific problems of fuel retention, impurity generation and lithium-ion deposition in the PWI process are studied. The specific contents are as follows: in the second chapter, the Ma is introduced. The LIBS in-situ PFM diagnosis system established on the gnum-PS I linear plasma device can obtain PFM elements high time and space resolution LIBS spectral signals under 10-7 mbar background pressure. The successful establishment of this set of LIBS system is the first time that LIBS is first used in large linear plasma experimental devices. The high throughput deuterium produced by Magnum-PSI device is obtained. The deuterium retention and elemental distribution properties of pure tungsten, tungsten lithium carbide, original graphite tile and lithium fossil ink tile after irradiated by different doses of deuterium plasma were studied in situ (1024 m-2s-1) and in situ LIBS technique. It was found that lithium was obviously inhibited on the surface of tungsten. The experimental table showed that the lithium carbide was irradiated at 1.9 1025m-2 dose of deuterium plasma. The signal intensity of deuterium is obviously higher than the deuterium in the pure tungsten material, which is mainly caused by the strong chemical adsorption caused by the chemical reaction between lithium and deuterium. With the irradiation dose of the deuterium plasma increased to 6.21025 m-2, the samples of pure tungsten and lithium tungsten carbide have obvious deuterium retention saturation.LIBS depth analysis results. The signal of lithium, deuterium and hydrogen decreases with the depth of the depth, and the tungsten signal is strengthened with the depth first and then reaches the stable value. The deuterium plasma irradiation can make the lithium redeposition process and sputtering process reach the equilibrium.X ray photoelectron spectroscopy (X-ray Photoelectron Spectroscopy, XPS) off line analysis of the results of the distribution of each element obtained by LIBS and XPS. By analyzing the LIBS laser ablation pit of the samples of the tungsten lithium carbide, it is found that after the laser ablation, the deuterium plasma irradiation has made a significant redeposition of lithium. In the third chapter, the establishment of a low pressure DC cascade arc plasma beam device (DUT-PSI) is introduced. The luminescence intensity, the electron temperature, the vibration temperature and the rotational temperature of the shock wave region of the shock state are measured simultaneously. The results show that the plasma luminescence intensity is higher, the electron temperature is lower, the vibration temperature and the rotational temperature are higher in the compression zone of the shock state plasma. The temperature and the rotation temperature are higher. The plasma beam is in a remarkable non equilibrium state. After the optimization and upgrading of the structure of the DUT-PSI electrode, the device can produce a low temperature and high density plasma beam with the plasma parameters of the region of the partial filter. The electron temperature is 1-1.2 eV and the electron density can reach 21014 cm-3. It can be used to simulate the PWI related process of the lithium of tungsten. The three-dimensional distribution characteristics of lithium carbide and its impurity elements on the surface of the sample are studied by the chemical imaging system of the LIBS element. The study shows that the distribution of lithium, hydrogen, oxygen and argon on the surface of the tungsten carbide has a similar trend. The intensity of the hydrogen, oxygen and argon element is high in the region with high lithium signal intensity, but the distribution of the hydrogen, oxygen and argon element is high, but with the distribution of other elements such as tungsten. By off-line XPS spectrum analysis, the analysis results of LIBS chemical imaging are supported and the chemical states of elements in different locations such as the laser ablation zone and the tungsten carbide surface are analyzed. In the fourth chapter, the graphite tile of the filter in the 2012 EAST experiment period (the total discharge time of the watt 5621 times more than 50000 s) is carried out. The off-line LIBS analysis shows that deuterium retention on the graphite tile of the EAST filter is mainly caused by the lithium deuterium co deposition layer. The deuterium retention ratio (D/ (D+H)) increases with the depth first, and then stabilizes at about 0.17. This value can reflect the deuterium retention ratio at the filter tile at the EAST discharge. The effect of LIBS plasma collection area on LIBS signal acquisition is investigated. The spatial resolved LIBS analysis of common PFM samples, such as carbon, silicon and molybdenum, is analyzed. It is found that the signal intensity of carbon, silicon and molybdenum is from the laser ablated plasma due to the bremsstrahlung of the pulsed laser ablation plasma, the composite and the ultrasonic expansion process in the vacuum environment. The center to the edge is first raised and then dropped, and the effect of laser spot size and energy on the LIBS signal is studied. The other part of this chapter focuses on how to establish an in-situ LIBS wall diagnosis system on EAST tokamak. By rationally utilizing two reserved flange interfaces and optimizing the optical path setting, the LIBS technology and tools are realized for the first time in the world. With the combination of all superconducting tokamaks with partial filter position, the first wall of the first wall in the middle plane 1212cm2 range of the EAST high field side can be analyzed by the LIBS element. In the 2014 EAST experimental period, the in-situ measurement of the element changes on the wall surface was realized by LIBS, and the elements such as lithium, molybdenum, deuterium, hydrogen, tungsten, lanthanum, titanium, silicon, sodium and other elements in the surface of the EAST wall were successfully obtained. Signal; the thickness of the lithium deposition layer increased from 4 mu m to 9 Mu after the two 45 g lithium crucible evaporation wall treatment, the lithium pellet injection experiment and the 194 gun discharge, and the deuterium retention ratio (D/ (H+D)) on the first molybdenum wall (D/ (H+D)) was obtained between 61%-64%.

【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TL631.24;O536
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本文編號：1894591