一种新型TEA CO2激光器的实验研究

设计了一种新型结构的激光器———双通道放电激励折叠腔TEA CO2激光器。该激光器通过提高脉冲能量输出水平来增加激光输出谱线数目和激光差分吸收雷达可探测的气体种类。它在增大激光器放电时间长度的同时保证了较小的激光器体积,更好地满足了激光差分吸收雷达光源体积小,重量轻,输出能量高的要求。得到激光器输出能量与气体工作气压的关系曲线,获得了激光器内工作气压与输出脉宽关系曲线,发现脉冲宽度大约在50~70ns之间变化,研究了气体压强对激光器输出脉冲峰值功率的影响。     

小型折叠腔自由振荡TEA CO2激光器实验研究

分析了TEA CO2激光器和差分吸收雷达的工作原理,研制了一种新型双通道放电激励折叠腔TEA CO2激光器.详细分析了折叠腔TEA CO2激光器的结构及其设计特点.对影响气体快放电过程的各种因素,如储能电容与峰值电容的比值、工作气压、充放电电感及输入电压的范围等进行了实验研究,确定了充放电谐振回路的最佳参数,实现了双通道的稳定辉光放电.对激光器输出能量与激励电压、混合气体工作气压等参数的关系进行了实验研究,得到最大输出能量约为722 mJ.     

Experimental investigation on wake profile detection based on laser scattering by bubbles

The optical system for detecting wake profiles based on laser backscattering by bubbles at 180°is reported, in which the monostatic optical geometry is adopted and the power density estimation is used to process bubble scattering signal.The profiles of wakes produced by a two-blade propeller with a diameter of 46 mm at 6000 and 8000 rpm are measured using this system.It is shown that the wake region can be identified,the wake with different shapes can be distinguished,and the fine structure within wakes can be detected.Also,the repeatability of the results is tested experimentally.Results show the feasibility of this system in wake profile detection.     

固态准分子激光介质的实验研究

固态稀有气体卤化物准分子激光器是最近几年出现的一种新型激光器。它的工作物质是用气体矩阵隔离技术、在低温(10-20K)情况下生长的矩阵晶体。固态介质的特点是有与气相介质相似的激光能级;粒子数密度比气相高4-5数量级;可消除卤素特别是F_2的腐蚀作用。     

平面研磨加工中工件转速的理论分析

平面研磨加工中工件转速决定了磨具与工件间的相对运动速度分布,并进而影响磨具和工件的面形精度。在考虑了磨具上金刚石丸片的实际排列以及接触区压强的实际分布的前提下,运用力学和运动学的方法,模拟分析了在固着磨料平面研磨加工中镜盘所受的摩擦力矩。在此基础上,根据稳定加工时力矩平衡原理得出了包含转速的数学公式,并重点探讨了工件半径和偏心矩对工件转速的影响。结果表明,工件转速并不总是等于磨具转速,而是随着偏心矩的增大而逐渐增高,随着工件半径的变化发生起伏波动。     

Application of plasma shutter in second harmonic generation of AgGaSe2 crystal

A reliable target-triggering plasma shutter was applied to second harmonic generation (SHG) of AgGaSe2 crystal with a TEA CO2 laser. Under normal air pressure, argon charged plasma shutter was triggered by focusing beam companying with a pair of adjustable metal targets. Conversion efficiency was enhanced by 3.3 times and the maximal efficiency 9.3%, with 1.4-mJ second harmonic energy was obtained. Finally, crystal damage was discussed together with previous work.     

利用Townsend放电测定N_2(A~3∑_u~ )亚稳态分子的扩散系数和猝灭速率常数

在纯N_2气体中,利用Townsend放电方法,对N_2(A~3∑_u~ )亚稳态分子的扩散系数D_m和猝灭速率常数K_q的测定进行了研究。分别得到:D_m=128cm~2/s,K_q=8.1×10~(-19)cm~3/s。     

利用Townsend放电测定N2(A3∑u+)亚稳态分子的扩散系数和猝灭速率常数

在纯N₂气体中,利用Townsend放电方法,对N₂(A³∑_u⁺)亚稳态分子的扩散系数D_m和猝灭速率常数K_q的测定进行了研究。分别得到:D_m=128cm²/s,K_q=8.1×10^-19cm³/s。 关键词：