Multi-Tube Hollow Cathode Plasma Source for Wear and Power Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hollow cathode systems used for creating plasma have limited operating time due to wear and tear, require frequent replacement of wearing parts, and face challenges in scaling plasma power effectively.
Innovation Solution
A hollow cathode system with at least two electrically connected cathode tubes, each with a separate gas adjuster and auxiliary ignition device, allowing for independent operation and adjustment of arch discharges to extend operating time and control plasma intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a single hollow cathode is used, then the device complexity is low, but the operating time is limited due to wear
Solution Approach 1:
The cathode is divided into multiple segments (first cathode and second cathode) that can be independently activated. When one cathode segment wears out, the other can continue operation, thereby extending the overall operating time without requiring complete replacement of the cathode assembly.
Solution Approach 2:
The patent implements a system where worn cathode segments can be discarded or replaced independently while retaining functional cathode segments. This allows recovery and continuation of operation using remaining functional segments, reducing downtime and extending effective operating time.
2Power
If the discharge current is increased to achieve higher plasma power, then the plasma intensity is improved, but the cathode reaches melting temperature and emits excessive material
Solution Approach 1:
The total discharge current is distributed across multiple cathode segments rather than concentrated on a single cathode. This segmentation allows achieving higher total plasma power while maintaining lower current density on each individual cathode, preventing melting and excessive material emission.
Solution Approach 2:
Instead of overloading a single cathode to achieve high power, the system uses multiple cathodes operating at partial load. The combined output of multiple cathodes running at moderate current densities achieves the desired total plasma power without exceeding the thermal and material emission limits of individual cathodes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system achieves extended operating time by rotating cathode tubes and allows for adjustable plasma intensity by activating or deactivating cathode tubes, reducing material waste and operational costs.
Implementation Method 1
an arc discharge can be formed between the cathode tube and the anode assembly within a vacuum chamber
Implementation Method 2
Hollow cathode plasma sources are used for a variety of applications, such as plasma activation of PVD processes
Implementation Method 3
Ions from the plasma zone impact the inner cathode wall, thus providing electrons for discharge via secondary electron emission
Implementation Method 4
the construction of arc evaporators, or as a heat source
Implementation Method 5
the high operating temperatures lead to increased sputtering rates, evaporation, recrystallization
Data Source
Figure 1
Figure 2a~2b
Figure 3
AI summary
The invention relates to a hollow cathode system for generating a plasma and to a method for operating such a hollow cathode system, in which an anode device (13), a power supply device (14) for providing an electrical voltage applied between a cathode tube (11a; 11b) and the anode device (13), and at least one gas reservoir (15) for providing a gas flowing through the cathode tube (11a; 11b) are used. At least two cathode tubes (11a; 11b) are used, which are electrically conductively connected to one another, and each cathode tube (11a; 11b) is assigned a separate actuator (17a; 17b), by means of which the quantity of gas flowing through the cathode tube (11a; 11b) assigned to the relevant actuator (17a; 17b) is set.