Using a hydrodynamic two-temperature model, we simulate multi-pulse laser ablation of an aluminum bulk target. The results of modeling demonstrate that the effectiveness of the multi-pulse ablation increases an order of magnitude in comparison to a single-pulse ablation of the same energy, while the repetition rate grows up to several GHz because the material surface does not cool down substantially between successive pulses. To prevent the shielding and suppression effects, the fluence of each pulse in the burst should have a subthreshold value to avoid the generation of slow moving ablated condensed-phase nanolayers. The obtained results are consistent with recent experiments on ablation by ultrafast bursts of ultrashort pulses.

We present quantum molecular dynamics calculations of thermophysical properties of solid and liquid molybdenum in the vicinity of melting. Detailed analysis of available experimental isobaric expansion data and extensive comparison over a wide set of properties with results of first-principle calculations is presented, possible reasons of contradictions are discussed. Accurate calculation of zero isobar confirms the density of solid Mo measured by electrostatic levitation technique and the lowest density of molten Mo observed in pulse heating experiments, that gives a substantial volume change on melting of about 5.5%.

In this work we provide a step by step derivation of an angular-averaged Ewald potential suitable for numerical simulations of disordered Coulomb systems. The potential was first introduced by E Yakub and C Ronchi without a clear derivation. Two methods are used to find the coefficients of the series expansion of the potential: based on the Euler–Maclaurin and Poisson summation formulas. The expressions for each coefficient is represented as a finite series containing derivatives of Jacobi theta functions. We also demonstrate the formal equivalence of the Poisson and Euler–Maclaurin summation formulas in the three-dimensional case. The effectiveness of the angular-averaged Ewald potential is shown by the example of calculating the Madelung constant for a number of crystal lattices.