Detection of pulsed current induced by laser-induced desolvation of hydrated electrons in water jet immersed in low-pressure plasma

Hydrated electrons are generated by plasma-liquid interaction. However, there have been limited reports on the detection of hydrated electrons in liquids interacting with plasmas. The difficulty is caused by the fact that hydrated electrons generated by the plasma irradiation are localized in a narrow region with a thickness of several nanometers below the plasma-liquid interface. To overcome the difficulty, we have developed a method to detect hydrated electrons in the interfacial region. Hydrated electrons in the interfacial region are converted to free electrons when they are irradiated with laser beam having a photon energy exceeding the desolvation energy. Free electrons produced by the desolvation are transported to the gas phase. In a previous work, we used an atmospheric-pressure helium dc glow discharge with the liquid cathode, and observed the pulsed increase in the discharge current when the liquid cathode was irradiated with the 4th harmonics of a Nd:YAG laser pulse. In the present work, we try to detect hydrated electrons in a micro water jet immersed in a low-pressure plasma. We detected the pulsed current from the plasma to the water jet when the water jet was irraditated with the 4th harmonics of a Nd:YAG laser pulse.