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1.
J. Kodymová O. Špalek V. Jirásek M. Čenský G.D. Hager 《Applied Physics A: Materials Science & Processing》2003,77(2):331-336
This article addresses the development of a Chemical Oxygen-Iodine Laser (COIL) with alternative chemical ways of generating
atomic iodine. Injection of atomic iodine as opposed to molecular iodine has the potential to improve the COIL efficiency.
This paper describes two chemical methods for generating iodine atoms based on the gas phase reactions of hydrogen/deuterium
iodide with fluorine or chlorine atoms, which are also produced chemically. Simplified one-dimensional gas dynamic modeling
that describes the stream-wise profiles of species concentrations within both reaction systems is used to gain a theoretical
understanding of both reaction systems under COIL conditions. The modeling results are used for the design of an experimental
device and the interpretation of experimental data. The first experimental investigation studies the production of iodine
atoms produced from reactions of Cl with HI. Atomic iodine yields of 70–100% in nitrogen are obtained, and the gain on the
I(2
P
1/2)–I(2
P
3/2) transition in a flow of singlet oxygen is measured.
Received: 7 October 2002 / Accepted: 8 February 2003 / Published online: 28 May 2003
RID="*"
ID="*"Corresponding author. Fax: +420-2/8689-0527, E-mail: kodym@fzu.cz 相似文献
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Results of spectral and photometric measurements are presented for pulsed operated high-pressure-sodium lamps. Choosing for the colour temperature a value of 3000 K, the output spectrum was optimized with respect to colour rendition and lamp efficacy taking the pulse parameters, the sodium mole fraction, and the cold spot temperature as quantities to be varied. For the nominal rating of 70 W a maximum lamp efficacy of 70 lm/W and a colour rendering index of 40 can be obtained. Further improvements of the colour rendition require an enhanced sodium vapour pressure which can be achieved by operating the lamp at rised cold spot temperature. 相似文献
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氧碘高能激光近场存在较多的杂散光,这些光会严重影响光束传输和光束质量控制。通过对杂散光的产生机理、类型和传输规律的分析和模拟确定了不同类型杂散光的测量方法。利用两个能量计测量了30m通道自由传输时的传输效率,利用测试光阑获得了通道内杂散光角谱曲线和镜面散射光能量。实验表明30m通道自由传输时的能量损失约为5.2%,杂散光的角谱随着传输距离的增加逐渐增大,角谱也会随着光束质量的恶化显著增加。利用角谱曲线可以获得通道内任意位置处光阑上的热负荷,这为高能激光热管理技术奠定了坚实的基础。 相似文献
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报道了脉冲钛宝石激光器的双波长可调谐运转,双汉总能量达到41.8mJ,调谐范围大于100nm并且研究了双波长运转时的竞争效应,增益损耗的影响,时域特性等。 相似文献
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Bulat P. V. Volkov K. N. Grachev L. P. Esakov I. I. Lavrov P. B. 《Technical Physics》2021,66(11):1177-1185
Technical Physics - The development of efficient and reliable ignition systems for fuel mixtures is of interest for many practical applications associated with the use of combustion power plants.... 相似文献
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100W全光纤化高重频窄脉宽光纤激光器 总被引:2,自引:0,他引:2
报道了一种基于主振荡功率放大结构工作的全光纤化高重复频率窄脉冲宽度光纤激光器.种子源是一个直接电脉冲调制的1 063 nm光纤耦合输出半导体激光器.为了抑制放大器中产生的放大自发辐射光,将种子激光的脉冲波形调制为二阶超高斯型.峰值功率为950 mW的半导体激光器经过2级大模场掺镱双包层光纤放大器(纤芯分别为10μm和30μm)功率放大后,最终获得了平均功率为101 W、重复频率为200 kHz、脉冲宽度为14.77 ns、峰值功率为34.2 kW、3 dB光谱宽度为0.261 nm、光束质量M~2为1.17的脉冲激光输出.与传统的纳秒级脉冲光纤激光器相比,该激光器峰值功率高、光束质量优、光谱宽度窄、结构简单,可广泛应用于激光雷达、遥感探测、倍频和光参量震荡等领域. 相似文献
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Magnetic and Gas Sensing Property of Nanosized NiFe2O4 Powders Synthesized by Pulsed Wire Discharge 总被引:1,自引:0,他引:1
P. Y. Lee K. Ishizaka H. Suematsu W. Jiang K. Yatsui 《Journal of nanoparticle research》2006,8(1):29-35
Nickel ferrite (NiFe2O4) powders were synthesized by pulsed wire discharge method. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses show that only nickel ferrite spinel and no other phase was observed in the powders. Mean size of the obtained particles strongly depended on the oxygen pressure: the higher oxygen pressure corresponds to larger powder size, as determined by Brunauer–Emmet–Teller (BET). The room temperature saturation magnetization of the synthesized powders was 42–46 emu/g depending on the powder size. These powders also showed high chlorine sensitivity at about 280–360°C, and a good linear sensitivity with chlorine concentration. 相似文献
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T. Idehara T. Saito H. Mori H. Tsuchiya La Agusu S. Mitsudo 《International Journal of Infrared and Millimeter Waves》2008,29(2):131-141
Long pulse operation up to 1 msec of a high frequency gyrotron with a pulse magnet has been successfully carried out in a
frequency range including 1 THz. In the experiments, the timing of an electron beam pulse injection is adjusted at the top
of the magnetic field pulse, where the variation of field intensity is negligible. The operation cavity modes seem to be TE1, 12 and TE4,12 at the second harmonics. The corresponding frequencies are 903 GHz and 1,013 GHz, respectively. Additionally several features
of radiation measurement results of the gyrotron are described and brief considerations are presented. 相似文献
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近年来对水中高压脉冲放电等离子体特性的诊断研究越来越受到重视。测量单个放电脉冲放电等离子体的时间-空间分辨发射光谱,有助于研究水中脉冲放电等离子体的时空演化动力学特性和规律。在本研究中将四分幅超高速相机和单色仪结合,构建了一种跟踪单个放电脉冲的高速时空分辨光谱仪,开发了相应的光谱分析软件。用波长632.8 nm的He-Ne激光器,在1 200 g·mm-1刻线光栅条件下对光谱仪的性能进行了测试。结果表明:对应He-Ne氦氖激光632.8 nm谱线的像素分辨率为0.013 nm。在曝光时间20 ns时,单色仪狭缝宽度0.2 mm时632.8 nm谱线的仪器展宽为(0.150±0.009)nm,仪器展宽随着狭缝宽度的增加呈现增大趋势。曝光时间的变化不会引起仪器展宽的变化,能够确保在调节相机曝光时间的过程中不影响光谱仪性能。利用该高速分辨光谱仪对水中纳秒火花放电发射光谱进行了测量,单次曝光获得了单一脉冲放电等离子体时空演化光谱。今后进一步完善实验室的电路条件消除放电干扰,可以对单个放电脉冲进行更细致的测量,为研究单个放电脉冲等离子体参数的时空演化特性提供良好的技术手段。 相似文献
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Wavelength-Tunable Rectangular Pulse Dissipative Soliton Operation of an Erbium-Doped Mode-Locked Fiber Laser 下载免费PDF全文
The wavelength-tunable rectangular pulse dissipative soliton (DS) is experimentally demonstrated, for the first time to the best of our knowledge, in an erbium-doped figure-of-eight fiber laser based on the nonlinear amplifying loop mirror mode-locked technique. The proposed rectangular pulse DS fiber laser can operate in the wavelength- tunable mode-locked state from 1573.5nm to 159d.6 nm with the rotation of the polarization controllers. The achieved output wavelengths are 1573.5nm, 1576.3nm, 1586.8nm, 1590.4nm and 1594.6nm, respectively. The pulse widths of the rectangular pulse can also be tuned from ~8ns to ~24ns by adjusting the pump power. The fundamental repetition rate of the rectangular pulse DS is 1.154 MHz and the output power is 6.1d m W (at 1594.6 nm). 相似文献
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脉冲激光退火纳米碳化硅的光致发光 总被引:3,自引:0,他引:3
采用XeCl准分子脉冲激光退火技术制备了纳米晶态碳化硅薄膜(nc-SiC),并对薄膜的光致发光(PL)特性进行了分析。结果表明,纳米SiC薄膜的光致发光表现为300~600 nm范围内的较宽发光谱带,随退火激光能量密度的增加,nc-SiC薄膜398 nm附近的发光峰相对强度增加,而470 nm附近发光峰相对减小。根据nc-SiC薄膜的结构特性变化, 认为这两个发光峰分别来源于6H-SiC导带到价带间的复合发光和缺陷态发光,并且这两种发光过程存在竞争。 相似文献
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利用发射光谱研究脉冲电晕放电中的自由基 总被引:10,自引:2,他引:10
利用发射光谱技术在大气压下测量了以氮气为载气的不饱和水蒸气体系针-板式正脉冲电晕放电产生的OH(A^2∑→X^2Ⅱ0—O)自由基和O(3p^5P→3s^5S^02777.4nm),Ha(3P→2S 656.3nm)活性原子的发射光谱,并由N2(C^3Ⅱu→B^3Ⅱg)的△v=-3和△v=-4振动带序发射光谱强度计算得出N2(C,v)的相对振动布居及其振动温度,进而采用高斯分布拟合准确地求出了N2(C^3Ⅱu→B^3Ⅱg)的△v= 1振动带序发射光谱强度,从而可以由N2(C^3Ⅱu→B^3Ⅱg)的△v= 1振动带序与OH(A^2∑→X^2Ⅱ0—0)的重叠发射光谱中准确求出OH(A^2∑→X^2Ⅱ0—0)自由基的发射光谱强度。由发射光谱强度得到了激发态OH(A^3∑)自由基和O(3p^5P),Ha(3P)活性原子的布居。还研究了激发态OH(A^2∑)自由基和O(3p^5P),Ha(3P)活性原子的布居随放电电压和放电频率的变化以及氧气对激发态OH(A^2∑)自由基和O(3p^5P),Ha(3P)活性原子布居的影响。 相似文献
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采用自制实时取样系统及四极质谱仪测量TEACO2激光器放电过程中气体组分变化,分析了测量结果对TEACO2激光器放电状态的影响。 相似文献
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用Ar气作保护气体 ,气压保持在一个标准大气压 ,用Nd :YAG脉冲激光烧蚀Al靶获得等离子体。利用时空分辨技术 ,采集了激光脉冲能量在 5 2 ,92 ,115和 14 5mJ情况下等离子体辐射的时空分辨谱。详细描述了 115mJ时等离子体的辐射特征 ,简要分析了其他脉冲能量下Ar的特征辐射规律。根据这些脉冲能量下Ar 特征谱线的分布规律 ,简要论述了Ar气体电离与激光脉冲能量的关系。讨论了环境气体电离机制 ,并对结果进行了简单解释。结果发现 ,在本实验采用的能量范围内 ,较高的脉冲能量更容易使环境气体电离 ,产生较强的Ar 离子辐射 ,且Ar 辐射持续时间较长。 相似文献
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Nanostructured indomethacin (IM) – bovine serum albumin (BSA) composite particulates below 50 nm were obtained by pulsed laser deposition (PLD) with 1064 nm IR beam. IM and BSA powders were coground for up to 210 min to prepare conjugated targets for PLD with varying structural states. The ablation threshold was determined to be around 1.8 J/cm2, from in situ monitoring of the deposited amount by a QCM sensor. The crystallinity of IM was preserved after PLD at 5 J/cm2 and decreased with increasing the laser fluence. The non-crystalline state of IM in the target after prolonged cogrinding with BSA, was also preserved in the deposited film. FT-IR absorption bands due to amide I of BSA became sharper while preserving the peak top position after cogrinding with IM. Conversely, we observed broadening of the amide I bands by PLD. Preservation and change in the chemical and structural states of the conjugates after PLD is discussed in terms of the secondary structure of BSA and crystallinity of IM. 相似文献