管状预电离可调谐TEA CO2激光器.

研制了一种新型的预电离结构--管状预电离器,并将其应用于可调谐TEA CO2激光器.利用光栅选线方案,采用光栅谐振腔,实现了激光的调谐输出.在输出耦合率为50%、气压为40 kPa的条件下,10P(20),10R(20),9P(20),9R(20)四条谱线获得的最高电光转换效率,分别为9.5%,9.7%,9.8%,9....     

Coupling coefficient for TEA CO2 laser propulsion with variable pulse repetition rate

Because pulse repetition rate affected directly the momentum coupling coefficient of transversely excited atmospheric (TEA) CO2 laser propulsion, a double pulse trigger, controlling high voltage switch of laser excitation circuit, was designed. The pulse interval ranged between 5 and 100 ms. The momentum coupling coefficient for air-breathing mode laser propulsion was studied experimentally. It was found that the momentum coupling coefficient decreased with the pulse repetition rate increasing.     

Experimental investigation of the effects of laser parameters on laser propulsion

The effects of main laser parameters,such as pulse energy,pulse duration,frequency,and work time on laser propulsion of "air-breathing mode",are investigated experimentally with a high power and high repetition frequency TEA-CO2 pulsed laser.The results show that the momentum coupling coefficient Cm decreases with increasing the pulse energy for single pulse tests and pulse duration of about 1μs.Either higher or lower frequency will reduce Cm in multi-pulse tests,which suggests an optimal frequency for the maximum Cm.As to the work time,the longer the work time is,the less the Cm will be.     

激光推进冲量耦合系数测量方法比较

 针对测量冲量耦合系数的水平导轨法和冲击摆法,分别进行了误差计算和实验研究。计算结果表明:水平导轨测量法的相对误差（4.6%）略小于冲击摆测量法的相对误差（6.1%）,其中位移参数和最大摆角的测量精度对于相对误差的影响最大。实验结果表明:两种方法的测量结果基本一致,冲量耦合系数均随着入射脉冲能量的增大而增大,且两组数据相差在6%以内,在入射脉冲能量为3~14 J时,冲量耦合系数最高可达260 N·MW^-1。     

激光脉冲重复频率对冲量耦合系数的影响

 设计了触发间隔从100 ms到5 ms可调的双脉冲触发器驱动TEA CO₂激光器高压开关，用以模拟激光器不同的输出脉冲重复频率。用该装置精确控制的不同激光脉冲重复频率下，对抛物面型光船模型进行了大气模式激光推进中冲量耦合系数的实验研究。发现冲量耦合系数随着重复频率的增加而下降，而单位时间内光船获得的冲量耦合系数的增量则随着重复频率的增加而增大。初步分析认为，这是由于飞行器内的空气未得到充分的补充造成的。     

Experimental investigation of the effects of laser parameters on laser propulsion

The effects of main laser parameters, such as pulse energy, pulse duration, frequency, and work time on laser propulsion of "air-breathing mode", are investigated experimentally with a high power and high repetition frequency TEA-CO_2 pulsed laser. The results show that the momentum coupling coefficient C_m decreases with increasing the pulse energy for single pulse tests and pulse duration of about 1 μs. Either higher or lower frequency will reduce C_m in multi-pulse tests, which suggests an optimal frequency for the maximum C_m. As to the work time, the longer the work time is, the less the C_m will be.     

TEA CO2激光器预电离结构电极系统的电场研究

 高功率气体激光器的非对称复杂电极系统中,电极参数的变化以及预电离结构的引入将会使所设计的均匀电场发生具体的改变。采用高精度有限元方法,对这类复杂电极系统进行建模并且计算其电场分布,根据分析结果更合理地指导激光器设计。对一种典型的非对称复杂电极系统TEA CO₂激光器,应用该方法并结合了预电离过程,研究了引入预电离器导体和变化电极形状对电极表面的电场强度起伏和放电空间的均匀电场面积产生的影响。结果表明:通过这种预先模拟,合理选择电极构型参数和预电离结构安装位置,可以产生性质较好的均匀电场以及效率较高的激光输出。