why use Ar to ignition plasma

There are several reasons why Ar (argon) is commonly used to ignite plasma in various applications:

Inert gas: Ar is an inert gas, meaning it does not readily react with other substances. This property makes it ideal for creating a stable and controlled environment for plasma formation without interfering with the chemical reactions occurring in the plasma.
High electron mobility: Ar has a relatively low ionization energy, which means it requires less energy to strip electrons from its atoms and create a plasma. This high electron mobility makes it easier to initiate and sustain a plasma discharge.
Low cost and availability: Ar is one of the most abundant gases in the Earth's atmosphere, making it readily available and relatively inexpensive compared to other noble gases like helium or neon. This makes it a cost-effective choice for plasma ignition.
Thermal stability: Ar has good thermal stability, meaning it can withstand high temperatures without decomposing. This makes it suitable for applications that involve high-temperature plasmas, such as plasma cutting or welding.
Optical properties: Ar emits a distinctive blue-violet glow when energized, which makes it useful for visualizing and studying plasma phenomena. This property is often utilized in plasma research and diagnostics.

Overall, the combination of Ar's inertness, electron mobility, availability, thermal stability, and optical properties makes it a widely used gas for igniting and sustaining plasma in various industrial, scientific, and technological applications