Strongly coupled plasma and photonic crystal at high pressure plasmas

We have developed an experiment platform to generate high-density strongly coupled (SC) plasma states [1,2], relevant to the interior of our Sun and other celestial objects. A focused ns laser pulse of moderate energy (100s mJ) in supercritical fluids of noble species (He, Ar, Kr, and Xe) generates a SC plasma with a relatively low temperature of ~ 1 eV (estimated by blackbody fitting) and a surprisingly high density exceeding ~10²¹ cm^-3. We invoke an ionization potential reduction mechanism to explain such a high density [3] and discuss about weakly degenerate nature of the plasma and a possibility of photonic structure formation therein.

[1] Lee S., et al., Nature Commun.12 (2021) 4630.

[2] Lee S., et al., Plasma Phys. Contrl. Fusion 64 (2022) 095010.

[3] Lee J., et al., under review.