High current bi-polar pulse system for use in electrochemical metal surface finishing
AssigneeJefferson Science Associates, LLC
InventorsCHARLES REECE, HUI TIAN, JOHN MUSSON
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Abstract
A high current bi-polar pulse system for use in electrochemical metal surface finishing of metallic components. The high current bi-polar pulse system provides a high isolation, high current switching device for providing independently controllable, alternating polarity, variable time duration pulses for electrochemical and mechanical finishing of metallic components in a conducting fluid bath. The high current bi-polar pulse system provides a safe, low-cost solution for implementing the surface finishing of niobium (Nb) SRF accelerating cavities without the use of hydrofluoric acid.
Claims14
An apparatus for electropolishing a superconductive radio frequency cavity comprising:
- a cathodic voltage source comprising a first variable direct current power supply and a first capacitor bank in electrical communication with said first variable power supply;
- an anodic voltage source comprising a second variable direct current power supply and a second capacitor bank in electrical communication with said second variable power supply;
- a counter-electrode at least partially disposed in an electrolytic fluid which is in contact with a niobium cavity to be polished;
- a first conductive path between said cathodic voltage source and said counter electrode;
- a second conductive path between said anodic voltage source and said counter electrode;
- a cathodic voltage switch positioned within the conductive path between said cathodic voltage source and said counter-electrode;
- an anodic voltage switch positioned within the conductive path between said anodic voltage source and said counter-electrode;
- and,
- a timing control circuit disposed to control the operation of said voltage switches.
An apparatus for electropolishing a superconductive radio frequency cavity comprising:
- at least two direct current power supplies;
- at least two capacitor banks;
- each capacitor bank connected to a separate direct current power supply;
- a counter electrode connected to said capacitors via a conduction pathway;
- said counter electrode being in communication with an electrolytic fluid and said fluid being in contact with a surface of niobium cavity;
- at least two switching devices positioned to regulate the conduction pathway between said capacitors and said counter electrode;
- and,
- a timing control circuit disposed to operate said at least two switching devices.
A method of chemically processing a metallic work piece comprising the steps of:
- providing a source of cathodic voltage comprising a first direct current power supply and at least one first capacitor providing at least ten farads electrical capacitance and a source of anodic voltage comprising a second direct current power supply and at least one second capacitor providing at least ten farads electrical capacitance;
- connecting said sources of cathodic voltage and anodic voltage via a respective conduction path to an electrochemical cell comprising a metallic work piece, a counter electrode, and an electrically conducting fluid;
- and,
- using a timing control circuit to alternate discharge of said at least one first capacitor and said at least one second capacitor according to a predetermined programmed sequence.
Dependencies are inferred from the claim text.