Reconstruction of ejecta field based on photon Doppler velocimetry from shock-loaded samples in vacuum

Photon Doppler velocimetry (PDV) has been extensively used to measure the velocity of single objection or fragments under the impact; however, with the PDV measurement, how to recover the ejecta field, which is a high-velocity multiple-particles system, remains a challenge. Mie theory is applied to describe the light-particle scattering process, and Monte Carlo algorithm is introduced to simulate PDV spectrums. By the simulations, how the PDV spectrum is qualitatively influenced by the velocity profile, particle size, and total area mass of ejecta is revealed. Then a novel optical model is proposed to derive the quantitative relationships between these ejecta parameters and PDV spectrum characteristics. With this model, the ejecta parameters can be extracted from PDV spectrum directly. Estimated values of the ejecta parameters from experimental spectrum are in good agreement with those measured by piezoelectric probe.