Selective excitation of heavy water solution under infrared pulse irradiation: A molecular dynamics simulation study

Abstract

The heating effect of infrared pulses with varying frequencies on heavy water solutions of different concentrations was investigated using non-equilibrium molecular dynamics simulations. Numerical calculations indicate that when the pulse frequencies are 39 and 72 THz, the infrared pulses excite the heavy water molecules, while the temperature of the light water molecules remains unchanged. At pulse frequencies of 53 and 99 THz, the infrared pulses excite the light water molecules. Additionally, in the far infrared region (1–20 THz), the infrared pulses excite both heavy and light water molecules simultaneously, albeit with a significantly reduced energy absorption efficiency. We also conducted a comparative analysis of the energy absorption efficiency of water molecules under three distinct heating modes: Vibrational excitation, rotational excitation, and microwave heating. The results reveal that the energy absorption efficiency of vibrational excitation is seven times that of rotational excitation, and the efficiency of rotational excitation is seven times that of microwave heating. This conclusion holds great potential for practical applications.