Empirical formulas for hypervelocity impact with a piezoelectric element and their application to a new real-time dust detector

Hypervelocity collisions of microparticles with a lead-zirconate-titanate piezoelectric element are examined. The waveforms thus obtained depend on the velocities during collision, and are classified into three categories. In particular, the first cycle of the signal observed immediately after collision is essential to obtain information on the impact. In each category, experimental formulas that are functions of the impact velocity are established based on experimental data. It is concluded that a single piezoelectric element can potentially measure the velocity and/or momentum of hypervelocity microparticles in real time. In the abovementioned context, the new dust detectors are described.