Equation of State Measurements of Boron Nitride under Laser-Driven Compression at the Prague Asterix Laser System Facility

We have investigated the equation of state (EoS) of hexagonal boron nitride (h-BN) under extreme conditions using the Prague Asterix Laser System facility. The experiment employed a 438 nm wavelength laser pulse with a pulse duration of approximately 350 ps delivering up to 200 J of energy. A phase plate ensured a uniform flat-top intensity profile with a diameter of approximately 400 mu m. Shock wave velocities were simultaneously determined in BN and in a reference material from time- and space-resolved self-emission measurements using a streaked optical pyrometer. The EoS of BN was determined by comparing its response to that of the reference material. We achieved high compression of BN (up to 9 Mbar). By expanding the experimental dataset on the EoS of h-BN, this study contributes to a more comprehensive understanding of behavior of this material under extreme conditions, supporting advancements in fusion energy research, high-energy-density physics and possibly next-generation inertial confinement fusion target designs.