Hollow Cathode Arc Discharge Ignition via High Voltage Pulses

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Solution Overview

Problem

Existing methods for igniting and maintaining a hollow cathode arc discharge require additional equipment and are inefficient, particularly at low working gas pressures, and often rely on heating coils that are unreliable and require separate power supplies.

Innovation Solution

A method and device that generate a magnetic field around the cathode with field lines parallel to the tube axis and provide electrical voltage pulses of at least 500 V to ignite and maintain the arc discharge, eliminating the need for heating coils and using a single power supply device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a heating coil is used to ignite the hollow cathode arc discharge, then the arc discharge can be ignited and maintained, but the ignition time is long (several minutes to hours), the heating coil wears out quickly requiring frequent maintenance, and additional separate power supply devices are required

Engineering Contradiction:
Improveignition reliabilityVSAvoidignition time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the thermal heating system (heating coil) with an electrical field-based ignition system. A high voltage pulse (at least 500 V) is applied between the cathode and anode to directly ionize the working gas and initiate the arc discharge, eliminating the need for thermal heating and its associated time losses and maintenance requirements

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs periodic high voltage pulses to ignite and maintain the arc discharge. The power supply device generates voltage pulses at specific intervals, with each pulse serving to reignite or sustain the discharge, replacing the continuous heating action with a periodic electrical stimulation that is more efficient and reliable

Inventive Principle:
Principle #19Periodic action

2Reliability

If a heating coil is used to ignite the hollow cathode arc discharge, then the arc discharge can be ignited, but additional separate power supply devices and control devices are required, increasing device complexity

Engineering Contradiction:
Improveignition capabilityVSAvoidnumber of power supply devices
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the ignition function and the maintenance power supply function into a single power supply device. The same power supply that provides the burning voltage (40-100 V) also generates the high voltage pulses (at least 500 V) needed for ignition, eliminating the need for separate heating coil power supplies and control devices

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The power supply device is designed to perform multiple functions: it provides the continuous burning voltage required to maintain the arc discharge and simultaneously generates the high voltage pulses needed for ignition. This multi-functional design simplifies the overall system by eliminating dedicated ignition circuits and heating coil power supplies

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Illumination intensity

If the working gas pressure inside the hollow cathode tube is reduced to generate intense plasma, then plasma intensity increases, but the arc discharge becomes unstable and may extinguish

Engineering Contradiction:
Improveplasma intensityVSAvoidarc discharge stability
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The patent uses periodic high voltage pulses to maintain the arc discharge stability at low working gas pressures. The pulses are applied at intervals that ensure the discharge is reignited before it can extinguish, allowing the system to operate at pressure levels that would otherwise be too low for stable continuous operation

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the electrical parameters by applying high voltage pulses (at least 500 V) that are significantly higher than the normal burning voltage. This parameter change enables the arc discharge to be maintained at low working gas pressures where the electric field strength from the pulses is sufficient to sustain ionization and prevent discharge extinction

Inventive Principle:
Principle #35Parameter changes

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

Enables rapid ignition and stable maintenance of hollow cathode arc discharges in a few milliseconds to seconds, preventing unintentional extinguishing and reducing equipment complexity and maintenance needs.

Implementation Method 1

a power supply device generates an electrical voltage between the cathode and anode, with the power supply device being able to generate on the one hand the burning voltage for the arc discharge and on the other hand at least one voltage pulse of at least 500 V to ignite or maintain the arc discharge

Methodology Applied
Scientific EffectElectrical breakdown: Electric Spark

Implementation Method 2

a magnetic field is generated around the cathode at least on the output side, which magnetic field has field line regions that are parallel to the tube axis or run at least largely parallel to the tube axis of the cathode

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Data Source

PatentEP2164309B1Method and device for operating a hollow cathode arc discharge
Publication Date: 2015.07.22 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP2164309B1 patent drawingFigure 1
  • EP2164309B1 patent drawingFigure 2
  • EP2164309B1 patent drawingFigure 3~4

AI summary

The invention relates to a method and a device for operating an arc discharge between an anode (15) and a tubular cathode (12) through which a working gas is passed into a vacuum chamber, wherein at least on the output side a magnetic field (17) is generated around the cathode (12) which has field line regions that run parallel to the tube axis of the cathode (12) and wherein an electrical voltage is generated between the cathode (12) and the anode (15) by means of a power supply device (18), wherein the power supply device (18) generates both the operating voltage for the arc discharge and at least one voltage pulse of at least 500 V for igniting or maintaining the arc discharge.