Method and apparatus for providing flow-stabilized microdischarges in metal capillaries

A method comprising:

• providing a conductive hollow elongate conduit having a longitudinal axis and an exit orifice;
• providing an anode electrically coupled to the voltage source and positioned at least at one point in time longitudinally distanced from but proximate to the exit orifice of the conductive hollow elongate conduit to allow striking of a discharge between the exit orifice and the anode;
• applying a voltage of direct or low frequency current to the conductive hollow elongate conduit, where the conductive hollow elongate conduit is maintained at a potential lower than the anode;
• and
• supplying a gas to the conductive hollow elongate conduit, so that upon application of the voltage to the conductive hollow elongate conduit a plasma is formed at least within the conductive hollow elongate conduit even at atmospheric pressures.

An apparatus for combination with a source of gas comprising:

• a conductive hollow elongate conduit having a longitudinal axis and an exit orifice;
• a voltage source of direct or low frequency current having a negative terminal electrically coupled to the conductive hollow elongate conduit;
• and
• an anode electrically coupled to the voltage source and positioned at least at one point in time longitudinally distanced from the exit orifice of the conductive hollow elongate conduit;
• wherein the source of gas is communicated with the conductive hollow elongate conduit to supply gas to the conductive hollow elongate conduit, so that upon application of the voltage to the conductive hollow elongate conduit, so that upon application of the voltage to the conductive hollow elongate conduit a plasma is formed at least within the conductive hollow elongate conduit,
• wherein the conductive hollow elongate conduit is a cylindrical tube with an inner diameter of approximately 200 μm or less.

A method comprising:

• providing a conductive hollow elongate conduit having a longitudinal axis and an exit orifice;
• providing an anode electrically coupled to the voltage source and positioned at least at one point in time longitudinally distanced from the exit orifice of the conductive hollow elongate conduit
• applying a negative voltage of direct or low frequency current to the conductive hollow elongate conduit;
• and
• supplying a gas to the conductive hollow elongate conduit, so that upon application of the negative voltage to the conductive hollow elongate conduit a plasma is formed at least within the conductive hollow elongate conduit,
• wherein providing a conductive hollow elongate conduit provides a cylindrical tube with an inner diameter of approximately 200 μm or less.

An apparatus for combination with a source of gas comprising:

• a conductive hollow elongate conduit having a longitudinal axis and an exit orifice;
• a voltage source of direct or low frequency current having a negative terminal electrically coupled to the conductive hollow elongate conduit;
• and
• an anode electrically coupled to the voltage source and positioned at least at one point in time longitudinally distanced from the exit orifice of the conductive hollow elongate conduit;
• wherein the source of gas is communicated with the conductive hollow elongate conduit to supply gas to the conductive hollow elongate conduit, so that upon application of the voltage to the conductive hollow elongate conduit a plasma is formed at least within the conductive hollow elongate conduit,
• where the apparatus is capable of operating continuously in excess of at least 100 hours without replacement of the conductive hollow elongate conduit.

A method comprising:

• providing a conductive hollow elongate conduit having a longitudinal axis and an exit orifice;
• providing an anode electrically coupled to the voltage source and positioned at least at one point in time longitudinally distanced from the exit orifice of the conductive hollow elongate conduit
• applying a negative voltage of direct or low frequency current to the conductive hollow elongate conduit;
• and
• supplying a gas to the conductive hollow elongate conduit, so that upon application of the negative voltage to the conductive hollow elongate conduit a plasma is formed at least within the conductive hollow elongate conduit,
• where further comprising operating continuously in excess of at least 100 hours without replacement of the conductive hollow elongate conduit.