Experimental measurement of shock thickness in a strongly coupled dusty plasma*

Dusty plasma is a system of highly charged micron-size particles immersed in an ionized gas. Dusty plasma has much in common with warm dense matter (WDM): it can support shock waves, and it has a strongly coupled component. These common features allow us to use dusty plasma to study shock phenomena that also occur in WDM. An experiment we performed in a two-dimensional dusty plasma reveals that the shock width is as small as two interparticle distances. We were able to make this measurement at the particle level because dusty plasma allows the direct observation of individual particles.