Evolution of a laser plasma near a solid target in high pressure gases

A study is reported of the evolution of a laser plasma near the surface of a solid target subjected to neodymium laser radiation having a flux density $q$ which was varied over the range 1–10 MW/cm${}^2$. A qualitative analysis is made of the mechanism of laser plasma generation near a solid target, over a wide range of pressures $p$ (1–120 atm) of the gas surrounding it (nitrogen, helium). There are three plasma generation mechanisms, depending on the values of $q$ and $p$.