【摘要】：雙等離子體衰變?cè)诜谴呕す獾入x子體中已被廣泛研究,但是在托卡馬克磁化等離子體中,由于射頻波的功率相對(duì)較低,目前有關(guān)磁化等離子體雙等離子體衰變的理論和實(shí)驗(yàn)的研究都非常少。然而TEXTOR托卡馬克的實(shí)驗(yàn)研究發(fā)現(xiàn),當(dāng)200～600kW的電子回旋波加熱和電流驅(qū)動(dòng)穿越磁島時(shí),實(shí)驗(yàn)觀測(cè)到了強(qiáng)背散波以及離子加熱、加速的現(xiàn)象。電子回旋波的雙等離子體衰變能解釋這些現(xiàn)象,但當(dāng)前的線性理論表明該衰變過(guò)程因其高閾值功率而不可能發(fā)生,因此研究低閾值功率的磁化等離子體雙等離子體衰變產(chǎn)生機(jī)制是有必要的。本文在流體框架下,采用數(shù)值模擬和理論解析相結(jié)合的方法對(duì)磁化等離子體雙等離子體衰變過(guò)程展開(kāi)研究。一方面,在二維平板模型下利用等離子體波的雙流體方程組,開(kāi)發(fā)了在全時(shí)間和空間上研究雙等離子體衰變的并行程序。另一方面,采用弱模耦合近似的方法,解析地得到了磁化雙等離子體衰變過(guò)程的增長(zhǎng)率和閾值功率的表達(dá)式。最后根據(jù)TEXTOR托卡馬克電子回旋波加熱的實(shí)際參數(shù),通過(guò)并行程序結(jié)合解析結(jié)果計(jì)算了電子回旋波的雙等離子體衰變過(guò)程。在并行程序中,首次實(shí)現(xiàn)雙流體方程的完全匹配層(PML)數(shù)值邊界條件。討論了PML方法在雙流系統(tǒng)中的可行性和適定性,詳細(xì)推導(dǎo)了PML控制方程。線性系統(tǒng)的穩(wěn)定性分析和非線性方程的數(shù)值結(jié)果都表明,PML邊界是完全匹配的。數(shù)值結(jié)果同時(shí)顯示：PML的吸收效果與PML厚度和吸收系數(shù)直接相關(guān)；PML不影響計(jì)算區(qū)域內(nèi)部的物理過(guò)程；PML的吸收效果不受入射波功率強(qiáng)度和電子溫度的影響；PML的極大反射誤差小于1%。在理論解析工作中,著重考察了高混雜子波波數(shù)、等離子體密度和磁場(chǎng)對(duì)雙等離子體衰變絕對(duì)不穩(wěn)定性和對(duì)流放大的影響。結(jié)果表明：磁場(chǎng)對(duì)絕對(duì)不穩(wěn)定性的影響依賴于子波垂直和平行于泵波傳播方向的波數(shù)ky和kx；磁場(chǎng)強(qiáng)弱和波數(shù)匆的大小對(duì)絕對(duì)不穩(wěn)定性增長(zhǎng)率和對(duì)流放大的影響完全不同；磁場(chǎng)和密度在kx較小時(shí)對(duì)放大因子有顯著影響；線性阻尼和密度空間非均勻性對(duì)對(duì)流放大有抑制作用；相對(duì)于磁場(chǎng),密度的非均勻性對(duì)對(duì)流放大的影響更大。并行程序和閩值的解析結(jié)果計(jì)算均表明,在線性密度剖面下,TEXTOR托卡馬克電子回旋波發(fā)生雙等離子體衰變的閾值功率為十兆瓦左右。并行程序在非單調(diào)密度剖面下的計(jì)算結(jié)果顯示,閾值功率可以降低1個(gè)量級(jí),但仍無(wú)法解釋實(shí)驗(yàn)。若采用非單調(diào)密度剖面并考慮動(dòng)理學(xué)的修正效應(yīng),并行程序計(jì)算結(jié)果發(fā)現(xiàn),雙等離子體衰變閾值功率(約200kW)可以降低2個(gè)量級(jí)左右,能解釋實(shí)驗(yàn)現(xiàn)象。結(jié)合線性色散關(guān)系所示的子波俘獲效應(yīng),本文的研究結(jié)果從理論角度證明,非單調(diào)的密度剖面和子波的俘獲效應(yīng)可以顯著降低磁化雙等離子體衰變的閾值功率,為更進(jìn)一步開(kāi)展射頻波與磁化等離子體非線性相互作用提供參考。
[Abstract]:Double plasma decay has been widely studied in unmagnetized laser plasma, but in tokamak magnetized plasma, the power of RF wave is relatively low. At present, there are few theoretical and experimental studies on the double plasma decay of magnetized plasma. However, the experimental study of TEXTOR Tokamak shows that when the electron cyclotron wave of 200~600kW is heated and the current is driven across the magnetic island, the phenomenon of strong backscatter wave and ion heating and acceleration is observed experimentally. The double plasma decay of the electron cyclotron wave can explain these phenomena, but the current linear theory shows that the decay process is impossible because of its high threshold power. Therefore, it is necessary to study the mechanism of double plasma decay in magnetized plasma with low threshold power. In this paper, the process of double plasma decay in magnetized plasma is studied by means of numerical simulation and theoretical analysis under the framework of fluid. On the one hand, a parallel program for the study of double plasma decay in full time and space is developed by using the two-fluid equations of plasma waves in a two-dimensional plate model. On the other hand, the expressions of the growth rate and threshold power of magnetized double plasma decay process are obtained analytically by using the weak mode coupling approximation method. Finally, according to the actual parameters of TEXTOR tokamak electron cyclotron wave heating, the double plasma decay process of electron cyclotron wave is calculated by parallel program and analytical results. In the parallel program, the perfectly matched layer (PML) boundary condition for the two-fluid equation is realized for the first time. The feasibility and suitability of PML method in two-flow system are discussed, and the PML control equation is deduced in detail. The stability analysis of linear systems and the numerical results of nonlinear equations show that the PML boundary is perfectly matched. The numerical results also show that the absorption effect of PML is directly related to the thickness and absorption coefficient of PML. The absorption effect of PML is not affected by the power intensity of incident wave and the electron temperature. The maximum reflection error of PML is less than 1. In the theoretical analysis, the effects of high hybrid wavelet number, plasma density and magnetic field on the absolute instability and convection amplification of double plasma decay are investigated. The results show that the effect of magnetic field on absolute instability depends on the wave number Ky and KX which are perpendicular to and parallel to the direction of pump wave propagation, and the effect of the magnitude of magnetic field intensity and wave number on absolute instability growth rate and convection amplification is completely different. The magnetic field and density have a significant effect on the amplification factor when KX is small; the linear damping and density spatial inhomogeneity can inhibit the convection amplification; compared with the magnetic field, the density inhomogeneity has a greater effect on the convection amplification. The parallel program and the analytical results of the threshold values show that the threshold power of the double plasma decay of the electron gyrotron wave of TEXTOR tokamak under the linear density profile is about ten megawatts. The results of the parallel program under the non-monotone density profile show that the threshold power can be reduced by one order of magnitude, but the experiment can not be explained. If the nonmonotone density profile is adopted and the modified effect of kinetic theory is taken into account, the parallel program results show that the threshold power of double plasma decay (about 200kW) can be reduced by about two orders of magnitude, which can explain the experimental phenomenon. Combined with the wavelet trapping effect shown by linear dispersion relation, the theoretical results show that the nonmonotone density profile and wavelet capture effect can significantly reduce the threshold power of magnetized double plasma decay. It provides a reference for the further development of nonlinear interaction between RF waves and magnetized plasmas.
【學(xué)位授予單位】：華中科技大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：TL612

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 馮曉;龔學(xué)余;;電子回旋波在等離子體中的傳播[J];西華大學(xué)學(xué)報(bào)(自然科學(xué)版);2009年01期

2 童洪輝,趙長(zhǎng)林,田忠玉,顧彪;磁鏡等離子體中電子回旋波加熱實(shí)驗(yàn)的理論研究[J];核聚變與等離子體物理;1992年03期

3 彭曉煒;龔學(xué)余;尹陳艷;周超;;中心負(fù)剪切模式中的電子回旋波電流驅(qū)動(dòng)(英文)[J];上海師范大學(xué)學(xué)報(bào)(自然科學(xué)版);2007年01期

4 彭曉煒;龔學(xué)余;劉文艷;劉燕;尹陳艷;;電子回旋波在熱等離子體中的功率沉積[J];核聚變與等離子體物理;2007年04期

5 彭曉煒;龔學(xué)余;劉文艷;;中心負(fù)剪切模式中的電子回旋波電流驅(qū)動(dòng)數(shù)值模擬(英文)[J];湘潭大學(xué)自然科學(xué)學(xué)報(bào);2006年04期

6 鄭平衛(wèi);龔學(xué)余;劉文艷;何麗華;;電子回旋波與快波協(xié)同效應(yīng)的數(shù)值研究[J];核聚變與等離子體物理;2011年01期

7 劉才根,錢(qián)尚介,萬(wàn)華明;電子回旋波驅(qū)動(dòng)的托卡馬克芯部等離子體極向旋轉(zhuǎn)[J];物理學(xué)報(bào);1998年09期

8 洪斌斌;陳少永;唐昌建;張新軍;胡有俊;;托卡馬克中電子回旋波與低雜波協(xié)同驅(qū)動(dòng)的物理研究[J];物理學(xué)報(bào);2012年11期

9 周小兵,趙長(zhǎng)林;電子回旋波使磁鏡中捕獲電子與逃逸電子相互轉(zhuǎn)化[J];物理學(xué)報(bào);1993年08期

10 彭曉煒;龔學(xué)余;劉文艷;高金生;劉燕;黃千紅;李新霞;;發(fā)射波功率密度對(duì)電子回旋波電流驅(qū)動(dòng)的影響[J];核聚變與等離子體物理;2010年01期

相關(guān)會(huì)議論文 前3條

1 洪斌斌;陳少永;高敏;唐昌建;;電子回旋波與低雜波聯(lián)合驅(qū)動(dòng)的匹配條件研究[A];第十五屆全國(guó)等離子體科學(xué)技術(shù)會(huì)議會(huì)議摘要集[C];2011年

2 魯煒;劉宇;唐昌建;;HL-2A裝置上低雜波與電子回旋波協(xié)同驅(qū)動(dòng)的實(shí)驗(yàn)分析[A];第十五屆全國(guó)等離子體科學(xué)技術(shù)會(huì)議會(huì)議摘要集[C];2011年

3 鄭平衛(wèi);龔學(xué)余;何麗華;杜丹;;電子回旋波注入下的三維Fokker-Planck方程求解[A];中國(guó)核科學(xué)技術(shù)進(jìn)展報(bào)告（第二卷）——中國(guó)核學(xué)會(huì)2011年學(xué)術(shù)年會(huì)論文集第7冊(cè)（核電子學(xué)與核探測(cè)技術(shù)分卷、脈沖功率技術(shù)及其應(yīng)用分卷、核聚變與等離子體物理分卷）[C];2011年

相關(guān)博士學(xué)位論文 前3條

1 湯允迎;CFETR 20兆瓦電子回旋加熱微波系統(tǒng)設(shè)計(jì)[D];中國(guó)科學(xué)技術(shù)大學(xué);2016年

2 李景春;托卡馬克中電子回旋波和高諧快波電流驅(qū)動(dòng)的研究[D];南華大學(xué);2016年

3 孫新鋒;磁化等離子體雙等離子體衰變過(guò)程的數(shù)值模擬和理論研究[D];華中科技大學(xué);2016年

相關(guān)碩士學(xué)位論文 前2條

1 呂知平;托卡馬克中電子回旋波電流驅(qū)動(dòng)及電流分布控制[D];南華大學(xué);2010年

2 鄺躍軍;HL-2A裝置上電子回旋波加熱的實(shí)驗(yàn)研究[D];南華大學(xué);2010年

，

本文編號(hào)：2186231