Application of Photoelectric Magnification Tubes(PMT) in Light Flash Trend Measurements During Hypervelocity Impact

To investigate the light flash intensity and trend generated by hypervelocity impact,an experimental system for impact flash photoelectric magnification tuber (PMT) measurement has been designed.The measurement system is composed of four channels,in which fibre-optics probe collects the flash signals of different wavelengths and feeds it to PMT.The flash signals are transformed to electric signals and amplified by PMT,and then fed to the oscilloscope.The flash for given positions and azimuth angles at different impact conditions are obtained by two-stage light gas gun loading experiments.Impact flash intensity in turn is obtained by calculation according to measurement system calibration.Experiments illustrated that the characteristics of impact flash were obvious,an intensity peak appeared firstly followed by a long-lasting blackbody decay.