## 2 Materials and Methods  
### Mechanism of Dielectric-Enhanced Shockwaves  
The energy conversion mechanism from the discharge of the energy storage device to the generation of shockwaves that fracture the rock through electrical explosion, including the processes of energy input, output, and loss [23], is illustrated in the main stages of energy conversion as shown in Figure 1.  
The initial stored energy E\({}_{\text{total}}\) in the system is released through a high-voltage switch. When the voltage reaches the breakdown voltage, the air gap is ionized, forming a conductive path. At this stage, due to the inherent impedance of the circuit and the dielectric medium, a portion of the energy is lost as joule heat, denoted as E\({}_{\text{loss}}\). The main current then begins to flow into the metal wire, and this effectively injected energy is denoted as E\({}_{\text{se}}\). The energy E\({}_{\text{se}}\) is further divided into two parts: one portion, E\({}_{\text{pt}}\), is used for the phase transition of the metal wire, including Joule heating, melting, vaporization, and ionization into plasma; the other portion, E\({}_{\text{de}}\), is deposited within the discharge channel. As the metal wire vaporizes and forms a high-temperature, high-pressure plasma, the discharge channel begins to expand rapidly. During this process, energy is primarily converted into two forms: the first is the energy of the intense shockwave, E\({}_{\text{sw}}\), generated by compressing the surrounding medium; the second is the internal energy, E\({}_{\text{ie}}\), retained within the plasma, including thermal energy and ionization energy. As the shockwave propagates through the liquid medium, it is gradually attenuated due to the medium's resistance and viscosity, with the energy loss during this process denoted as E\({}_{\text{ot}}\). The effective mechanical energy that ultimately acts on the target object (such as rock) is denoted as E\({}_{\text{b}}\). Firstly, in the process where the energy E\({}_{\text{se}}\) injected into the metal wire is converted into the channel deposition energy E\({}_{\text{de}}\), the factors of electrical conductivity and the ambient pressure of the liquid medium play a significant role. In a high-conductivity liquid medium, due to the shunting effect, part of the energy dissipates into the surrounding medium, which slows down the rate of energy injection into the metal wire. This alters the processes of metal wire evaporation, ionization, and plasma formation during the electrical explosion, thereby extending the duration of the explosion [24; 25]. As the hydrostatic pressure increases, the intensity of light radiation decreases, while the expansion of the discharge channel is suppressed, leading to an increase in plasma density. [PERSON] et al., through electrical explosion experiments with tungsten wires under high-pressure conditions and magnetohydrodynamic numerical simulations, found that the high-pressure environment delays the electrical explosion of the tungsten wire [26], allowing more energy to be injected into the metal wire and increasing the deposition energy within the wire. To study the effects of these two factors, potassium chloride (KCI) and sodium chloride (NaCl) aqueous  
Figure 1: Energy conversion efficiency of electrical explosion. liquids, which have high solubility and are non-polluting, were chosen as the factors influencing electrical conductivity. Carbon dioxide (CO\({}_{2}\)) gas was used to increase the ambient pressure in the liquid medium as a factor influencing environmental pressure. Secondly, during the process where the channel deposition energy E\({}_{\text{de}}\) interacts with the surrounding liquid medium to enhance shockwave energy E\({}_{\text{sw}}\), physical and chemical reactions occur. The electrical explosion shockwave and radiation products can ignite micrometer metal particles, releasing additional thermal energy, shockwaves, and gases. This release further amplifies the explosive performance and effectiveness. [PERSON] et al.