The Analysis Technique for Ejecta Cloud Temperature Based on Atomic Spectrum

Six hypervelocity impact tests of aluminum projectiles impacting aluminum plates were carried out. The range of projectile diameters was 2.0mm-5.0 mm and the impact velocities varied from 3.0 km/s to 6.0 km/s. All the tests were normal impact. The atomic emission spectra of hypervelocity ejecta cloud are obtained by the instantaneous spectrometer. Six aluminum peaks and two concomitant peaks are identified in the emission spectrum. The effects of the concomitant peaks are analyzed and decoupled. Based on the spectral data, the ejecta cloud temperatures are analyzed using the Boltzmann diagram method and the configuration fitting method independently and the results are basically the same. The implication of the fact that the particle temperature of the ejecta cloud is uneven is discussed. It is found that for the uneven particles, the measurement result tends to be shifted toward the highest temperature of measuring time.