Monitoring of hydrocarbon concentrations in dust-producing RF plasmas
Monitoring of hydrocarbon concentrations in dust-producing RF plasmas
复制标题
监测产生粉尘的射频等离子体中的碳氢化合物浓度
DOI：
10.1088/0963-0252/21/5/055001
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发表时间：
2012
影响因子：
3.8
通讯作者：
J. Röpcke
中科院分区：
文献类型：
--
作者：
F. Hempel;D. Lopatik;B. Sikimić;I. Stefanović;J. Winter;J. Röpcke
用红外可调谐半导体激光吸收光谱(TDLAS)和傅里叶变换红外光谱(FTIR)相结合的方法，研究了含有C2、H2和CH4混合物的Ar和He射频等离子体中与尘埃粒子形成有关的碳氢化学。实验在射频电容耦合平行板反应器中进行，频率f=13.56 MHz，压力p=0.1mbar，流量Φ=8sccm，混合气体为0.5sccm C2 H2或1sccm CH4，功率为P=15W。用TDLAS监测了等离子体中甲基自由基和4种稳定分子C2 H2、CH4、C2 H4和CO的浓度随时间的变化。同时，用傅里叶变换红外光谱分析了粉尘颗粒的生长过程。在稳定的Ar和He等离子体条件下，乙炔前驱体的离解程度在96%范围内几乎是恒定的。相反，甲烷前体的离解程度在45%到90%之间变化，这取决于(I)反应堆体积中尘埃颗粒的出现和(Ii)Ar或He等离子体条件。甲基自由基的浓度范围为10~11个分子cm−~3。所有碳氢化合物的浓度与粉尘形成的动力学有很强的相关性。乙炔(RF(C2 H2)=3.2×10 16分子J−1)和甲烷(RF(CH4)=(0.16~2.5)×10 16分子J−1)的裂解效率和对所产生的烃类(RC=(0.2 3~8.5)×10 14分子J−1)的转化效率可根据射频等离子体中的放电条件进行估算。
In Ar and He radio-frequency (RF) plasmas with admixtures of C 2 H 2 and CH 4 the hydrocarbon chemistry has been studied in relation to dust particle formation by means of infrared tunable diode laser absorption spectroscopy (TDLAS) combined with Fourier transform infrared (FTIR) spectroscopy. The experiments were performed in a RF capacitively coupled parallel plate reactor at a frequency of f= 13.56 MHz, a pressure of p= 0.1 mbar and a flow rate of Φ= 8 sccm of Ar or He with admixtures of 0.5 sccm C 2 H 2 or 1 sccm CH 4. The power was P= 15 W. Using TDLAS, the temporal evolution of the concentrations of the methyl radical and of four stable molecules, C 2 H 2, CH 4, C 2 H 4 and CO, was monitored in the plasma. Simultaneously, the growth process of the dust particles was analysed by FTIR spectroscopy. The degree of dissociation of the acetylene precursor was found to be nearly constant in the range of 96% under stabilized conditions for both the Ar and He plasmas. In contrast, the degree of dissociation of the methane precursor varied between 45% and 90% depending (i) on the appearance of dust particles in the reactor volume and (ii) on the Ar or He plasma conditions. The methyl radical concentration was found to be in the range of 10 11 molecules cm− 3. The concentrations of all hydrocarbon species were strongly correlated with the dynamic of the dust formation. Fragmentation efficiencies of acetylene (R F (C 2 H 2)= 3.2× 10 16 molecules J− 1) and of methane (R F (CH 4)=(0.16–2.5)× 10 16 molecules J− 1) and conversion efficiencies to the produced hydrocarbons (R C=(0.23–8.5)× 10 14 molecules J− 1) could be estimated in dependence on the discharge conditions in the RF plasma.
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影响因子：
2.9
作者：
Benedikt, J.;Consoli, A.;von Keudell, A.
通讯作者：
von Keudell, A.
低压 Ar/C2H2 等离子体中尘埃颗粒生长速率的令人惊讶的温度依赖性
DOI：
--
发表时间：
2011
期刊：
影响因子：
--
作者：
J. Beckers;G. Kroesen
通讯作者：
G. Kroesen
Ar/CH4 和 Ar/C2H2 等离子体中的粉尘形成
影响因子：
3.8
作者：
J. Winter;J. Berndt;S;E. Kovačević;I. Stefanović;O. Stepanović
通讯作者：
O. Stepanović
含甲烷的 H2 表面波放电中的碳氢化合物化学
影响因子：
3.8
作者：
L. Mechold;J. Röpcke;X. Duten;A. Rousseau
通讯作者：
A. Rousseau
甲基自由基 nu2 基带的线强度和过渡偶极矩。
DOI：
10.1063/1.1812755
发表时间：
2005
期刊：
The Journal of chemical physics
影响因子：
--
作者：
G. Stancu;J. Röpcke;P. Davies
通讯作者：
P. Davies