最新刊期

    37 10 2016
    • Optical Oxygen Nanosensors Towards Biomedical Applications

      PENG Hong-shang, SHEN Rui-ying, WANG Xiao-hui
      Vol. 37, Issue 10, Pages: 1167-1176(2016) DOI: 10.3788/fgxb20163710.1167
      摘要:The determination of oxygen concentration is of great importance in biological applications. In recent years, significant progress has been made in the field, and nanosized optical oxygen sensors have gained particular attraction owing to the merit of high sensitivity, good photostability, facile bioconjugation and ideal dimension for in vitro and in vivo applications. In this review, we focus on optical oxygen nanosensors, including the types of suitable oxygen probes, structure properties, preparation methods, and different detection modalities. In addition, for different O2 nanosensors, the analytical performance and applicability in specific biological applications are also outlined. Generally this review is meant to give the potential user a guide to select the most suitable optical oxygen nanosensor and detection modalities for their particular biological detection.

        
      关键词:optical nanosensor;oxygen sensing;phosphorescence quenching;biomedical imaging   
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    • WEN Shu-min, ZHAO Chun-wang, WANG Xi-jun, LI Ji-jun, HOU Qing-yu
      Vol. 37, Issue 10, Pages: 1177-1181(2016) DOI: 10.3788/fgxb20163710.1177
      摘要:In order to understand the influence of annealing on the epitaxial film quality and optoelectronic properties, an epitaxial Ge film was grown on a Si(001) substrate via the two-step process using molecular beam epitaxy technique. The sample was divided into two pieces, and one piece of the sample was annealed. X ray double crystal diffraction rocking curves of (400) crystal plane for non-annealed and annealed epitaxial Ge films were measured by the high resolution double-crystal X-ray diffractometer. Fourier transform infrared transmittance and absorption spectra for non-annealed and annealed epitaxial Ge films were measured by the Fourier transform infrared spectrometer. The carrier concentration, mobility, resistivity, conductivity, and Hall coefficient of non-annealed and annealed epitaxial Ge films were also measured using the Hall effect device. The results show that the anneal treatment can improve the quality of epitaxial Ge films significantly. The absorption rate increases after anneal treatment and the transmittance in most area of epitaxial Ge film decreases dramatically. The transmittance decreases by 20% in the range of 615 to 3 730 cm-1. The carrier concentration increases 22.26 times, and the carrier mobility increases 27.82 times after anneal treatment.

        
      关键词:silicon based germanium thin film;infrared absorption spectrum;carrier concentration;mobility;conductivity   
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    • GUI Wei-jun, LIU San-qiu
      Vol. 37, Issue 10, Pages: 1182-1188(2016) DOI: 10.3788/fgxb20163710.1182
      摘要:The core-shell structure nanophosphors GdF3:Ce3+,Dy3+@GdF3:Eu3+ were synthesized via solvothermal method. XRD patterns show that the synthesized nanocrystallines(NCs) are orthorhombic phase both for the core and shell. Under the excitation of 8S7/26IJ of Ce3+, the core-shell structure nanophosphors exhibit well multicolor luminous performance, while for corresponding none core-shell structure nanophosphors, emission of Eu3+ denotes obvious fluorescence quenching phenomenon due to co-doping Ce3+. Based on the CIE(x, y) coordinate diagram, it can be seen that the core-shell structure nanophosphors own more excellent luminescent properties than that of the none core-shell structure nanophosphors due to the influence of Gd3+. Lastly, the influence of thickness of shell on lighting of the phosphors was discussed. It is found that the core-shell structure phosphors own the best emission intensity on condition that ratio of the core and shell is 1:3.

        
      关键词:GdF3 NCs;core-shell structure;multicolor luminescence;energy transfer   
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    • Infrared Optical Properties of Er3+ Doped Na5Lu9F32 Single Crystal

      TANG Qing-yang, WANG Cheng, XIA Hai-ping, HE Shi-nan, JIANG Hao-chuan, CHEN Bao-jiu
      Vol. 37, Issue 10, Pages: 1189-1194(2016) DOI: 10.3788/fgxb20163710.1189
      摘要:Er3+ doped Na5Lu9F32 single crystal was successfully grown by Bridgman method. The absorption spectra of the single crystal from 400 nm to 2 500 nm and the transmission characteristics from 2.5 μm to 25 μm were measured. Na5Lu9F32 single crystal possessed high optical transmittance from 400 nm to 7 150 nm wide band, and the transmittance reached to 90%. Almost no absorption of 2.7 μm band was observed. It indicated that the content of OH- ion was very low in the single crystal. The intensity parameters Ωt(Ω2=2.08, Ω4=2.07, Ω6=0.75) were calculated by using Judd-Ofelt theory based on the absorption spectrum. The radiative transition rates, branching ratios and radiative lifetimes were also obtained. The emission cross sections of the sample were 1.42×10-20 cm2(4I13/24I15/2) and 1.66×10-20 cm2(4I11/24I13/2) estimated by Futchbauer-Ladenburg formula. The emission spectra of 1.5 μm and 2.7 μm band were investigated under 980 nm LD.

        
      关键词:Er3+;Na5Lu9F32 single crystal;near-infrared;mid-infrared   
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    • ZHAN Xia-fei, TANG Jian-she, WU Jun
      Vol. 37, Issue 10, Pages: 1195-1202(2016) DOI: 10.3788/fgxb20163710.1195
      摘要:A novel carbon quantum dot was synthesized from (3-aminopropyl)-trimethoxysilane (APTMS) and glutaraldehyde (GA) by facile hydrothermal method based on Schiff's base reaction. The carbon quantum dot was spherical with a diameter of about 2-7 nm, and the excitation wavelength and maximum emission peak were 350 and 400 nm, respectively. The fluorescence quantum yield was up to 13.6%. The experiment results show that the optimal prepared condition of carbon quantum dots is APTMS and GA molar ratio of 1:2, heated at 180 ℃ for 8 h. The fluorescence intensity of carbon quantum dots is the maximum in pH 6.0 phosphate buffer solution. In addition, the fluorescence intensity decreases with the increase of the measuring temperature from 273 to 303 K.

        
      关键词:carbon quantum dots;Schiff's base reaction;glutaraldehyde;(3-aminopropyl)trimethoxysilane;optical properties   
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    • YE Xin-yu, LUO Yang, LIU Song-bin, HOU De-jian, YOU Wei-xiong, XIA Li-bin
      Vol. 37, Issue 10, Pages: 1203-1212(2016) DOI: 10.3788/fgxb20163710.1203
      摘要:LiGd(WyMo1-y)2O8-x/2Fx:0.4Eu3+ red phosphors with different F- and WO42- doping concentrations for white LEDs were synthesized by the solid state reaction method. Morphology, structure, optical properties of LiGd(WyMo1-y)2O8-x/2Fx:0.4Eu3+ phosphors were studied by scanning electron microscope(SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and fluorescence spectrometer. The results show that the samples doped with Eu3+, F- and WO42- have tetragonal scheelite structure. The optimum doping content of F- and WO42- is x=0.6 and y=0.4 , respectively. Under 396 nm excitation, the maximum emission intensity of LiGd(W0.4Mo0.6)2O7.7F0.6:0.4Eu3+ in which the quantum efficiency is 66.23% is higher than 60% in comparison with LiGd(MoO4)2:0.4Eu3+. When the temperature turned up to 100 ℃, the emssion intensity of LiGd(W0.4Mo0.6)2O7.7F0.6:0.4Eu3+ is 76.6% of the initial value at 25 ℃. Under 460 nm excitation, intense red emissions corresponding to 5D07F2 transitions of Eu3+ are observed. The chromaticity coordinates of LiGd(W0.4Mo0.6)2O7.7F0.6:0.4Eu3+ phosphors are (0.649 9, 0.346 3). Decay curve of 5D0 state for as-prepared samples fits the single order exponential behavior, the lifetime of 5D0 increases with the increasing of F- doping concentration, which is due to the reduction of non-radiative transition probability results from the low phonon energy property of F-. LiGd-(W0.4Mo0.6)2O7.7F0.6:0.4Eu3+ phosphors are suitable for the white LEDs.

        
      关键词:luminescence;red phosphor;white LEDs;solid state reaction   
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    • XIU Guang-jie, ZENG Qun, WANG Fei, YAO Chun-feng
      Vol. 37, Issue 10, Pages: 1213-1216(2016) DOI: 10.3788/fgxb20163710.1213
      摘要:Ce,Cr:YAG transparent ceramics were synthesized by solid state reaction method with high pure Al2O3, Y2O3,Cr2O3 and CeO2 as raw materials. The crystalline structure and optical properties of 0.5% Ce3+and 0.1% Cr3+ co-doped YAG ceramics were mainly studied by X-ray diffraction (XRD) and photoluminescence spectroscopy, respectively. XRD results show that the single YAG crystal phase is obtained when the precursor is sintered at 1 750 ℃. The linear transmission of the ceramic in visible range reaches about 70%. Under the excitation of 430 nm, the ceramic shows the characteristic emission peaks of Ce3+ and Cr3+, which might present it could be used in white-LED fields.

        
      关键词:Ce;Cr:YAG;solid state reaction method;transparent ceramic   
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    • Tunable Nonlinear Optical Properties of nc-Ge/SiNx Multilayers

      LI Cong, ZHANG Pei, JIANG Li-ying, CHEN Qing-hua, YAN Yan-xia, JIANG Su-xia
      Vol. 37, Issue 10, Pages: 1217-1222(2016) DOI: 10.3788/fgxb20163710.1217
      摘要:Nanocrystalline Ge (nc-Ge)/SiNx multilayers were fabricated by plasma enhanced chemical vapor deposition technique and post-thermal annealing method. The microstructure was characterized through Raman spectroscopy, and the calculated crystallinity was higher than 46%. The optical absorption spectra reveal that the band gap enlarges as the grain size of nc-Ge decreases. The nonlinear optical properties of nc-Ge/SiNx multilayers were investigated through Z-scan technique by using a mode-locking laser with 25 ps pulse duration at 1 064 nm as the pump laser. The measured nonlinear refractive coefficient was about 10-10 cm2/W. It is interesting to found the nonlinear optical refraction changes from the self-defocusing to self-focusing with the increasing of the grain size of nc-Ge, and the negative nonlinear refractive coefficient can be attributed to the free carries dispersion generated by tow-step absorption process. Moreover, two-step absorption and saturation absorption process coexist in the multilayers with 6 nm Ge layer as the pump intensity increases. The different optical nonlinearities are mainly originated from the competition between the two nonlinear absorption processes.

        
      关键词:nc-Ge/SiNx multilayers;saturable absorption;two-step absorption process;free carries dispersion   
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    • Gate Driver Integrated by MOTFTs Using Twice-bootstrap DC Output Module

      HU Yu-feng, LI Guan-ming, WU Wei-jing, XU Miao, WANG Lei, PENG Jun-biao
      Vol. 37, Issue 10, Pages: 1223-1229(2016) DOI: 10.3788/fgxb20163710.1223
      摘要:The gate driver integrated by metal oxide thin film transistors is able to lower the cost of driving ICs and narrow the bezel of display panel, but there are some disadvantages like poor power efficiency, slow response speed and small output swing for the existing output modules. In order to solve these problems, a novel twice-bootstrap DC output module was proposed, and a new gate driver topology was designed based on this module. The simulation results show that the circuit has strong driving ability and fast response speed. Finally, the gate drivers were successfully fabricated on glass substrate integrated by MOTFTs with etch stop layer structure. The power consumption of single stage of the gate driver is 325 μW.

        
      关键词:gate driver circuit;IZO thin film transistor;bootstrapping effect   
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    • FU Jia-iia, CAO Hai-cheng, ZHAO Li-xia, WANG Jun-xi, LI Jin-min
      Vol. 37, Issue 10, Pages: 1230-1236(2016) DOI: 10.3788/fgxb20163710.1230
      摘要:Highly stress tests were carried out for mid-power GaN-based LEDs encapsulated with silicone and green/red mixed phosphors. Except for the optical and electrical measurement, the reflection spectroscopy and time of flight-secondary ion mass spectrometry (TOF-SIMS) were also used to investigate the failure mechanism. Our results show that the high temperature and humidity play an important role in determining the failure mode for mid-power blue and white LEDs. The decrease of the blue emission is related to the degradation of the transparent silicone and the reflectivity by the oxidation and the contamination of sulfide and chlorine. While the dissolution of the phosphors in white LEDs will lead to the decrease of the conversion efficiency and deteriorate the photometric and colorimetric properties of mid-power white LEDs.

        
      关键词:mid-power LEDs;package materials;degradation behaviors   
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    • YANG Lan, ZENG Xiang-yao, ZOU Wei-dong, ZHANG Yong-ai, ZHOU Xiong-tu, GUO Tai-liang
      Vol. 37, Issue 10, Pages: 1237-1244(2016) DOI: 10.3788/fgxb20163710.1237
      摘要:In order to solve the problem of crosstalk caused by the mismatch between lenticular lens parameters and monitor pixel in multi-view 3D autostereoscopic display, a new method that could scale the three-dimensional composite image using image interpolation was presented. Taking the 9 viewpoint as an example, the scaling factor k was proposed, by which the bilinear interpolating scaling was improved. Embedded prototype test results show that the better match between lenticular lens parameters and monitor pixel leads to the better display effect. The crosstalk is reduced from 13.55% to 1.40% and the image resolution is improved effectively.

        
      关键词:lenticular lens;auto-stereoscopic display;interpretation algorithm;embedded system   
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    • WANG Qian, WU Ren-lei, WU Feng, CHENG Xiao-man
      Vol. 37, Issue 10, Pages: 1245-1252(2016) DOI: 10.3788/fgxb20163710.1245
      摘要:The distribution of potential and carrier density under various source drain voltage of organic field effect transistor with bottom-gate top-contact geometry was simulated using the multi-physical field software COMSOL on the basis of the finite element method. The potential has gradually changed from source electrode to gate electrode in the vertical direction with the increase of source drain voltage on the gate voltage Vg=-10 V and source drain voltage Vds in the range from 0 to -10 V, while the potential in the horizontal direction is even more obvious, which shows a gradient change from high to low. For the carrier density, the distribution of the carrier density reduces gradually from source electrode to drain electrode in the channel, and an evident reduction can be observed near the drain with the increase of source drain voltage. When the source drain voltage is equal to the gate voltage, the carrier density in the area reduces to a minimum and the phenomenon of pinch-off occurrs. Comparing the simulation results with the performance of devices, it is found that the simulation results have the same variation trend as that of the experimental data, which confirms the rationality of the simulation. In a word, it is instructive that the simulation method can be employed to analyze the characteristics of organic field effect transistor for the practical devices fabrication.

        
      关键词:organic field effect transistor;finite element method;potential;carrier   
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    • OUYANG Ai-guo, TANG Tian-yi, ZHOU Xin, LIU Yan-de
      Vol. 37, Issue 10, Pages: 1253-1258(2016) DOI: 10.3788/fgxb20163710.1253
      摘要:The mid-infrared spectroscopy was used to detect the content of methanol in the methanol diesel. Firstly, the collected original spectra were pre-processed by the standard normal transformation(SNV), multiple scatter correction (MSC), first derivative, second derivative and Savitzky-Goly smoothing methods. The quantitative model of methanol was established by partial least square method and least square support vector machine (SVM). The influence of different pre-processing methods on the model prediction capability was also investigated. The results show that LSSVM modeling is the optimal forecasting model with the prediction set correlation coefficient R2 of 0.981 8 and the prediction mean square error (RMSEP) of 1.3917%(volume ratio). So, the mid infrared spectrum technology can be used for the rapid detection of methanol in the methanol diesel and achieve very good results.

        
      关键词:MIRS;methanol diesel;PLS;LSSVM   
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    • SHEN Bing-jun, JIN Li-hong, ZHANG Jia-jia, LIU Rong-juan, LIU Zhan-wei, LIU Yu-xin, CHAI H
      Vol. 37, Issue 10, Pages: 1259-1266(2016) DOI: 10.3788/fgxb20163710.1259
      摘要:Under simulated physiological conditions, the binding mechanism between p-Coumaric acid (p-CA) and human serum albumin (HSA) was investigated by fluorescence spectrum and surface enhanced Raman scattering (SERS). The results show that the effect between p-CA and HSA is a static fluorescence quenching with Förster's non-radioactive energy transformation. At 298, 304, 310 K, the binding constants (KA) between p-CA and HSA are 3.41×104, 2.09×104, 1.38×104 L/mol, the binding site (n) value is approximate to 1. SERS reveals that the phenolic group of p-CA combines with HSA. Thermodynamic data indicate that the interaction between p-CA and HSA is mainly electrostatic attraction. Marker competition experiments point out that the primary binding site for p-CA is located at site Ⅰ in HSA. According to Förster energy transfer theory, the binding distance between p-CA and HSA is 5.11 nm. Synchronous fluorescence spectra show that the conformation of HSA does not changed apparently with the addition of p-CA.

        
      关键词:fluorescence spectrum;surface enhanced Raman scattering;p-Coumaric acid;human serum albumin;reaction mechanism   
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    • WANG Shu-tao, YUAN Yuan-yuan, WANG Yu-tian, ZHAO Xu, ZHANG Ya-ji, NIU Kai-zeng
      Vol. 37, Issue 10, Pages: 1267-1274(2016) DOI: 10.3788/fgxb20163710.1267
      摘要:The fluorescence spectra of permethrin in green tea and tieguanyin were studied. The fluorescence characteristic peaks of green tea and tieguanyin existed at λex/λem=(390-410)/675 nm, while the permethrin fluorescence characteristic peak existed at λex/λem=300/330 nm. To determine the content of permethrin in teas, a new method of a radial basis function (RBF) neural network based on a genetic algorithm (GA) was proposed. When the training is to 74, the precision of the mean square deviation reaches 10-3. The average forecast recovery rates of permethrin in green tea and tieguanyin are 99.35% and 98.89%, the average relative standard deviation are 1.25% and 1.21%, and the detection limit range is from 0.004 8 to 24 mg/kg, which is far lower than that of the EU rules of permethrin in tea maximum residue limits standards. Through the contrast of the RBF neural network model, it is found that the three-dimensional fluorescence analysis technology combined with GA-RBF neural network can predict the content of permethrin pesticide residue in teas quickly and easily, the detection sensitivity and the precision are higher.

        
      关键词:three-dimensional fluorescence spectra;genetic algorithm optimize the radial basis function neural network;concentration detection;permethrin;teas   
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    • XIONG Yang, ZHANG De-qing, GAO Fei, SI Min-zhen
      Vol. 37, Issue 10, Pages: 1275-1280(2016) DOI: 10.3788/fgxb20163710.1275
      摘要:The near-infrared surface-enhanced Raman scattering (NIR-SERS) spectra with high efficiency, stable and low-cost silver nanofilm were used to detect the oxyhemoglobin (OxyHb) of 25 healthy persons, 25 liver cancer patients and 25 liver cancer patients after surgery. Compared the intensity of three group spectra, it was found that the intensity of Raman peaks decreased in sequence for healthy persons, liver cancer patients after surgery and liver cancer patients, indicating that this method could preliminary judge the recovery situation of liver cancer patient after surgery. Meanwhile, by using principal component analysis (PCA) combined with linear discriminant analysis(LDA), 25 liver cancer patients after surgery were divided into two groups, 8 healthy persons and 17 liver cancers. It accorded with the actual situation. Therefore, PCA-LDA can more accurate judge the recovery situation of liver cancer patients after surgery. The results demonstrate that OxyHb NIR-SERS spectroscopy may be a potentially clinically useful tool for the diagnosis of recovery situation of liver cancer patients after surgery.

        
      关键词:spectroscopy;NIR-SERS;liver cancer after surgery;OxyHb;statistical analysis   
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    • Formation and Control of Airy Soliton in Kerr Media

      QIN Xu-lei, LI Xue-jian, CHEN Wei-jun, LI Ye, YANG Ji-kai
      Vol. 37, Issue 10, Pages: 1281-1286(2016) DOI: 10.3788/fgxb20163710.1281
      摘要:The propagation of Airy beams in self-focusing Kerr nonlinear media was investigated numerically by using split-step Fourier method. It is shown that spatial soliton with periodic oscillation can be formed out of the centered energy about the Airy main lobe during the propagation on the influence of stronger nonlinearity. With the increasing of the nonlinearity, the periodic and full width at half maximum (FWHM) of the soliton are decreased. The propagation trajectory of the shedding soliton is changed when the initial launch angle of Airy beam is adjusted. Different from Airy beams, the propagation of the Airy soliton is always maintaining straight line.

        
      关键词:nonlinear optics;Kerr media;Airy soliton   
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    • WU De-chang, YANG Shu
      Vol. 37, Issue 10, Pages: 1287-1291(2016) DOI: 10.3788/fgxb20163710.1287
      摘要:The coupled-resonator structure consisting of a T-shaped resonator and a nanodisk resonator was proposed and numerically investigated by using a two-dimensional finite element method. When the two cavities are at the condition of detuning, the plasmon-induced transparency (PIT) and the sharp asymmetric Fano lines will appear due to the difference of the cavities’transmittance. Fano-lines increase the sensitivity to 1.4×103 nm/RIU. The properties of the structure with different radii of the nanodisk and the length of the rectangle cavity were also analyzed. It is found that the PIT only happens when the staggered system is at around of a fixed location with different geometric construction. This model may be important for photonic-integrated circuits and the sensitivity in sensors.

        
      关键词:surface plasmon polarizations;waveguide filter;coupled resonator;quality factor   
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    • LIU Yang, CHENG Li, WANG Jia-chun, WANG Qi-chao, YUAN Zhong-cai, SHI Jia-ming
      Vol. 37, Issue 10, Pages: 1292-1298(2016) DOI: 10.3788/fgxb20163710.1292
      摘要:In order to investigate the protection performance of light emitting plasma to high-power microwave (HPM), a one-dimensional physical model of their interaction was built theoretically. The microwave transmission effect under different conditions was obtained by numerical simulation and the protection performance of light emit-ting plasma on HPM was analyzed. Then, the experiment about transmission effect of double columnar plasma arrays on 6 GHz HPM pulse was conducted. The effectiveness and veracity of the model were verified by comparing the results of theoretical calculation and experiment, and a nonlinear effect can be produced by the HPM plasma incidence. The results also show that TE polarization is better than TM polarization in protection. The plasma breakdown threshold decreases with the increase of the electric field space. The maximum attenua-tion of TE polarization can be up to 13 dB and increase further along with the input power.

        
      关键词:6 GHz HPM;light emitting plasma;protection;simulation;experiment   
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    • LIU Yao-ze, YUAN Cheng-xun, GAO Rui-lin, JIA Jie-shu, ZHOU Zhong-xiang
      Vol. 37, Issue 10, Pages: 1299-1304(2016) DOI: 10.3788/fgxb20163710.1299
      摘要:Low temperature helium plasma was generated using the coaxial hollow cathode configuration. In order to study the impact of the discharge power as well as the pressure of helium on the electron excitation temperature of plasma, calculation was performed based on the emission spectra data of plasma under different discharge conditions acquired by fiber optic spectrometer. The variation of electron excitation temperature was analyzed in relation to different experimental parameters. The results demonstrate that the emission spectra of low temperature helium plasma are comprised of continuum emission and the atomic spectrum of helium. The intensity of spectral lines change dramatically under different discharge conditions, although no visible shift of lines is observed. The electron excitation temperature increases almost linearly with the discharge power, rising from 5 566.4 K to 5 855.3 K, which is mainly owing to the growing acquisition of energy from the electric field. With the growth of helium pressure, the electron excitation temperature increases gradually from 5 203.7 K at 15 Pa to 5 941.3 K at 55 Pa, before decreasing slowly to 5 855.3 K at 75 Pa. This is because that the pressure will not only affect the averaged energy of the electrons gained in the electric field, but also the collision frequency between electrons and He atoms. By selecting proper discharge parameters of the coaxial hollow cathode system, the electron excitation temperature of helium plasma can be controlled.

        
      关键词:helium discharge;plasma;emission spectrum;electron excitation temperature   
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