Electron thermionic emission and tunneling transport in spherically symmetric charged grains in dusty plasmas

Electron emission from charged spherical dusty grains plays a crucial role in plasma environments, influencing charge dynamics and transport properties. This presentation explores thermionic emission and quantum tunneling as potential escape mechanisms for electrons in such systems. Using the Richardson-Dushman equation, we estimate thermionic emission currents at high temperatures, revealing significant electron loss under extreme conditions. Additionally, we analyze the feasibility of quantum tunneling, incorporating Debye shielding effects to assess barrier modifications and electron transmission probabilities. Our findings suggest that while thermionic emission dominates at elevated temperatures, tunneling can contribute non-negligibly in dense plasma conditions, influencing overall charge equilibrium. A promising direction for future probing is the impact of dynamic charge fluctuations on tunneling probabilities, which could further refine our understanding of electron escape processes in fluctuating plasma environments.