ICF系统用安全连锁模块的设计

Design of Safety Chain Module Used in ICF System

介绍了一种应用于惯性约束聚变(ICF)系统中的安全连锁模块的工作原理及其应用。该安全连锁模块对整个ICF系统的安全运行至关重要,尤其在ICF系统的预放大系统中大口径的光学元件极易因高峰值功率窄线宽激光引起横向受激布里渊散射(SBS)导致机械断裂。为保证整个ICF系统的安全运行,在ICF系统的前端系统中引入了相位调制器,其将线宽小于70kHz的种子光进行光谱展宽;同时,置于相位调制器之后的安全连锁模块用于检测相位调制器是否正常工作,其利用透射谱极窄的光纤光栅对光谱展宽后的中心波长为1 053nm的激光进行单边检测,在确认光谱被展宽至安全宽度后,给出使后续激光系统运行的电触发信号。经试验验证,该安全连锁模块原理简单、结构紧凑、判据可靠,对于大型激光系统的设计具有一定的参考意义。

The working principle and application of the safety chain module used in intertial confinement fusion（ICF）system are introduced.The safety chain module plays an important role in ICF system safe operation,especially,the mechanical fracture always happens in large diameter optics components in the pre-amplification system of ICF system due to the transient stimulated Brillouin scattering（SBS）caused by the high-peak power and narrowline width laser.Thus the front-end system of ICF system utilizes phase modulator to broaden spectrum of the seed light whose linewidth is under 70 kHz.Meanwhile,the safety chain module behind phase modulator is used to detect whether the phase modulator operates well,by using a FBG with ultra-narrow transmission spectrum to one-sided detect the light broadened spectrum with 1 053 nm central wavelength.Once the broadened spectrum is confirmed to be the safe linewidth,the safety chain module sends out an electrical trigger signal to start the following laser system operation.It is verified by experiments that the safety chain module has simple principle,compact structure and reliable criterion and has a certain reference value for large scale laser system design.