Time-Frequency Characteristics of Flash Produced by Hypervelocity Impact

It is a universal phenomenon of flash produced in hypervelocity impact. In order to investigate time-frequency characteristic of flash produced by hypervelocity impact, multi-channel spectral measurement system and optical pyrometer system were set up. Spectra at wavelength range 200~1 100 nm were measured in experiment. Through the NIST atomic emission spectral database, the spectral lines were identified. The spectral lines ALI 394.40 nm and 396.15 nm were analyzed. By comparing spectra under different impact velocities, the relationship between impact velocity and light intensity was formulated. Combined with the time variation of light intensity measured by optical pyrometer, the characteristics of flash were analyzed.