Different energy transport mechanisms come into play when intense laser pulses interact with dense plasma. Here the authors provide a limit on the plasma density reachable with an intense laser and an insight into the hole boring process.
Plasma exists in a mixed form of electrons, positive ions and neutral atoms or molecules and plays an important role in many processes; from astrophysical solar flares to nuclear fusion devices for energy applications. There is a strong research interest both in theory and experiment to understand how the plasma energy is transferred into other forms and how plasma behaves in different environments. Investigating these processes under extreme conditions in a table-top setting has become feasible due to the availability of high-power lasers.
In this collection we highlight a selection of recent experimental and theoretical research papers published on this multidisciplinary topic in Nature Communications. These articles feature research on fundamental plasma processes that are relevant to astrophysical events, energy transfer from laser to the particles during their acceleration, material development for plasma confinement and nuclear reactions in plasma fusion devices. This collection showcases the variety of research that different communities can bring together to better understand the ubiquitous processes in plasma.
High intensity light with a non-zero orbital angular momentum could aid the development of laser-wakefield particle accelerators. Here, the authors theoretically show that stimulated Raman backscattering in plasmas can generate and amplify orbital angular momentum lasers to petawatt intensities.
The electrons in a plasma can further ionize the ions when the two collide. Vinko et al. now study this ultrafast process in an unconventional plasma with a density similar to that of a solid, and show that the rate is several times higher than that predicted by standard theoretical models.
Charge screening dominates the behaviour of high-energy plasmas, which exist in stars and possibly in future fusion technology. Here, the authors describe a theoretical framework for charge screening that goes beyond the conventional model and demonstrate its importance in analysing experimental data.
Short pulses of high intensity laser light usually heat the ions in dense plasmas indirectly via collisions with the electrons. Here, the authors identify an extremely rapid alternative heating mechanism based on ion-ion collisions.
The energy loss of ions in plasma is a challenging issue in inertial confinement fusion and many theoretical models exist on ion-stopping power. Here, the authors use laser-generated plasma probed by accelerator-produced ions in experiments to discriminate various ion stopping models near the Bragg peak.
Studying the properties of dense plasmas is challenging due to strong interactions between electrons and ions, and numerical methods overcome this difficulty using a static thermostat. Here the authors predict a strong diffusive ion mode at low energy by including dissipative processes in the model.
The effect of dense plasma environment on the energy levels of an ion is usually described in terms of a lowering of its continuum level. Here the authors present an isochoric-heating experiment to measure and compare continuum lowering in single-species and mixture plasmas to provide insights for models.
Exploring the plasma processes in the pre-plasma state that lead to instabilities is challenging. Here the authors probe the evolution of the plasma phase change and the instabilities in plasma created by an exploding copper wire in Z-pinch geometry using shadowgraphy.
The electric wind mechanism remains unclear. Here, the authors report evidence that electric wind is caused by an electrohydrodynamic force generated by charged particle drag as a result of momentum transfer to neutral particles.