MEASUREMENT OF EJECTA WEIGTHING, PRESENTATION OF PROBES OMPTIMIZED FOR THEIR IMPLEMENTATION ENVIRONMENT AND RESISTANT TO EXTREME SOLICITATIONS

When a metallic sample is shocked, a cloud of particles may be released from its free surface, depending on the surface condition. This phenomenon, can be measured using a thin target weighing diagnostic, such as a µAsay.



This method allows one to estimate the ejected mass by measuring both the velocity of a metallic target and the velocity of particles measured by a velocimetry probe. A major challenge in structuring this diagnosis is the risk of particles depositing on the measurement system's lens, which causes early loss of measurement.

We present the technological solution found after experiments on powder launchers.



This effective and versatile diagnosis is capable of measuring different levels of solicitations by adjusting the material and thickness of the thin target. However, to respect the principle of thin target weighing, the target must not exceed 400 µm. A remaining challenge, however, is that in experiments with high levels of solicitation, even 400µm targets are destroyed, resulting in early loss of the optical signal.

We present experimental results on a new weighing probe, based on lithium fluoride, adapted to particularly violent particle ejections.