Penning effect

The Penning effect occurs when excited atoms or molecules transfer their energy to other atoms with lower ionization energy, causing the latter to release electrons. This process enhances ionization in gases, especially in plasma devices and lighting. It involves a collision where one particle in a higher energy state transfers energy directly to another, leading to its ionization without needing as much external energy. The Penning effect improves the efficiency of devices like neon signs and gas lasers by increasing the number of free electrons available for electrical conduction and light production.