The mechanisms which prevent sealed-off operation of Cu HyBrID lasers have been investigated by measuring the transient behavior of laser output power, Cu/sup 2/S/sub 1/2/ density, CuBr density and the voltage-current waveforms when buffer-gas flow is stopped during otherwise normal operation. The laser output, Cu/sup 2/S/sub 1/2/ density and CuBr density decay synchronously upon ceasing the flow, and fall to negligible levels within 60 s. The observed rate of decay, and the measured change in voltage-current waveforms during this period, are consistent with the calculated loss rate of Br from the plasma to the cold end-regions due to diffusion. During normal laser operation (i.e., with gas flow), this diffusion loss of Br occurs at a rate much faster than that possible due to the entrainment action of the gas flow, and approximately equals the rate at which HBr enters the laser tube with the gas flow. It is concluded that the principal role of buffer-gas flow is to continuously source Br species into the plasma to compensate for the Br diffusion loss. The implications for the practical operation of Cu HyBrID lasers and for the development of sealed-off Cu HyBrID-type lasers are discussed.
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机译:通过测量激光器的输出功率,Cu / sup 2 / S / sub 1/2 /密度,CuBr密度以及缓冲时的电压-电流波形的瞬态行为,研究了防止Cu HyBrID激光器密封运行的机制。否则,在正常运行期间,气流会停止。激光输出,Cu / sup 2 / S / sub 1/2 /密度和CuBr密度在停止流动时同步衰减,并在60 s内降至可忽略的水平。在此期间,观察到的衰减率以及电压-电流波形的变化均与由于扩散导致的从等离子体到冷端区域的Br损失率相一致。在正常的激光操作过程中(即在有气体流的情况下),由于气体的夹带作用,Br的扩散损失的发生速度比可能的发生速度快得多,并且大约等于HBr随HBr进入激光管的速度。气体流量。结论是,缓冲气体流的主要作用是将Br物质连续地供应到等离子体中,以补偿Br的扩散损失。讨论了对Cu HyBrID激光器的实际操作和封闭式Cu HyBrID型激光器的开发的意义。
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