Analysis of Plasma Ion-Target Collisions in Plasma Cutting Machines

What Is Plasma?

Figure 1: Four States of Matter

Matter is commonly classified into solids, liquids, and gases, but by heating a gas further, it is possible to generate plasma.

For this reason, plasma is often referred to as the “fourth state of matter.”

Plasma is created when particles such as ions, electrons, and atoms collide with one another.

In what kind of environment is plasma generated?

Plasma is mainly generated in extremely high-temperature regions such as the sun, or when a high voltage is applied to a gas.

In this article, we will analyze an industrial plasma cutting machine using PIC-PLASMA 3D (plasma analysis software).

A plasma cutting machine cuts metal by turning gas into plasma using electrical energy, then melting and blowing away the metal with an ultra-high-temperature, high-speed jet.

Figure 2: Conceptual Diagram of a Plasma Cutting Machine

The basic principle is as follows:

Plasma cutting is used for conductive materials such as iron, stainless steel, and aluminum. Gas such as compressed air or nitrogen is fed through a narrow nozzle while an arc is generated between the electrode inside the torch and the workpiece.

This arc ionizes the gas, creating a high-temperature conductive plasma flow that not only “melts” the metal but also “blows it away,” thereby achieving cutting.

Inside the equipment, a self-bias voltage is generated by applying high frequency to the electrode that holds the substrate, making it easier for ions to strike the substrate almost vertically. As a result, fine patterns can be processed deeply and accurately without widening sideways.

The features of a plasma etching system are:

These are its main advantages.

On the other hand,

These are some of the challenges.

In short, a plasma etching system is a device that precisely removes material from a surface by utilizing the chemical reactivity and ion bombardment of plasma generated in a vacuum.

Load Analysis on the Target in a Plasma Cutting Machine

Let’s perform a collision simulation on the target in a plasma cutting machine using PIC PLASMA 3D.

The analysis model is shown below.

Analysis Model

Figure 3: Analysis Model of the Plasma Etching System

A plasma cutting machine model like the one above was created, and plasma trajectory analysis and collision simulation on the target were carried out.

The plasma generation mechanism is shown below.

Figure 4: Plasma Generation Process

Analysis Conditions

The analysis conditions are as follows.

These initial conditions can also be set within the software (PIC-PLASMA3D).

Figure 5: Setting Analysis Conditions in PIC-PLASMA 3D

Analysis Results

Figure 6: Plasma Ion Trajectory Analysis in the Plasma Cutting Machine

 

 

Figure 7: Cumulative Plasma Collision Energy on the Target

The materials above are actual analysis results calculated using PIC-PLASMA3D.

Figure 6 visualizes the behavior of ions (O₂⁺) in the plasma as an animation. Figure 7 shows the cumulative collision energy (kinetic energy) between the target and the plasma.

You can see that ions generated by gas discharge in the plasma are colliding with the target.

This collision energy can be used to finely remove material from the target!

Please note that the CAD model used here was created in a simplified manner, so the electrode voltages and other conditions are also simplified.

In addition to the calculation results shown above, PIC-PLASMA 3D can output a variety of other data.

*The above are just examples. Please make full use of PIC-PLASMA 3D for the development of plasma-related products.