瞬态光谱测量中的触发与同步技术

设计加工了一套高速单脉冲触发电路,触发门限在150 mV～1.5 V范围内连续可调,输出脉冲宽度可自行调节,其响应时间小于50纳秒.提出了通过短脉冲半导体激光器测量触发延时的同步方案.在此基础上利用带像增强的ICCD探测器,建立了瞬态光谱测试系统,并实时测量了环氧丙烷爆燃转爆轰过程的瞬态光谱.触发与同步技术是研究的重点.

Trigger and synchronizer in instantaneous spectrum detection

A high speed single pulse trigger has been designed and fabricated. In a ultra-fast, low-power, precision TTL comparator (MAX913) the input signal level is compared with the scheduled trigger level which is set to logical state "1" once the input signal lever is higher than the scheduled trigger lever. The trigger threshold is adjustable between 150 mV～1.5 V. A TTL impulse, with its impulse width adjustable, is output from a dual non-retriggerable monostable multivibrator(74HC221). Using a dual-channel high speed digital optoisolator (HCPL2630) and assistant components, the trigger is automatically shutoff after it has output the first trigger impulse, ensuring it always outputs a single impulse. With the characteristic of the optoisolator that no internal feedback exists between the output and the input,the trigger not only can respond to weak signal, but also has very strong ability of resisting electromagnetic noise. Its response time is less than 50 ns. Afterwards, in this thesis a new synchronous scheme has been proposed in which a short impulse semiconductor laser is used to detect the t rigger delay exactly. It can be used as the synchronoust rigger in t ransient spect rum detection of shock compression. With a intensified CCD , we have set a apparatus for instantaneous spect rum detection. Using this apparatus we have detected instantaneous emission spect rum in epoxypropane deflagration detonation t ransition process. The keys of this work are t rigger and synchronization.