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.

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.

A method and apparatus for removing microscopic contaminant particulates by high pressure liquid nitrogen jet cleaning from the inner surface of a superconducting radio frequency cavity or a string of multiple cavities and transporting the removed particulates out of the inner space enclosed by the cleaned surfaces. The cleaning method of the invention suppresses field emission, resulting in an increase of the usable accelerating gradient of the cavities and a reduction of the activated radioactivity in accelerator components around cavities.

A method and apparatus for removing microscopic contaminant particulates by high pressure liquid nitrogen jet cleaning from the inner surface of a superconducting radio frequency cavity or a string of multiple cavities and transporting the removed particulates out of the inner space enclosed by the cleaned surfaces. The cleaning method of the invention suppresses field emission, resulting in an increase of the usable accelerating gradient of the cavities and a reduction of the activated radioactivity in accelerator components around cavities.

A cavity coupler comprising of an outer coupler body, at least one shield formed inside the outer coupler body wherein the relationship between the shield and the outer coupler body form at least one chamber, an antenna configured to provide a radio frequency signal, and a flange for connecting the cavity coupler to a superconducting cavity. In an embodiment, the outer coupler body is formed of stainless steel. In an embodiment, the at least one shield is formed of copper.

A cavity coupler comprising of an outer coupler body, at least one shield formed inside the outer coupler body wherein the relationship between the shield and the outer coupler body form at least one chamber, an antenna configured to provide a radio frequency signal, and a flange for connecting the cavity coupler to a superconducting cavity. In an embodiment, the outer coupler body is formed of stainless steel. In an embodiment, the at least one shield is formed of copper.

The present invention provides a process and structure of microfabricated air bridges for planar microwave resonator circuits. In an embodiment, the invention includes depositing a superconducting film on a surface of a base material, where the superconducting film is formed with a compressive stress, where the compressive stress is higher than a critical buckling stress of a defined structure, etching an exposed area of the superconducting film, thereby creating the at least one bridge, etching the base material, thereby forming a gap between the at least one bridge and the base material, depositing the at least one metal line on at least part of the superconducting film and at least part of the base material, where the at least one metal line runs under the bridge.

The present invention provides a process and structure of microfabricated air bridges for planar microwave resonator circuits. In an embodiment, the invention includes depositing a superconducting film on a surface of a base material, where the superconducting film is formed with a compressive stress, where the compressive stress is higher than a critical buckling stress of a defined structure, etching an exposed area of the superconducting film, thereby creating the at least one bridge, etching the base material, thereby forming a gap between the at least one bridge and the base material, depositing the at least one metal line on at least part of the superconducting film and at least part of the base material, where the at least one metal line runs under the bridge.

An accelerator comprising at least one accelerator cavity, an electron gun, at least one cavity cooler configured to at least partially encircle the accelerator cavity, a cooling connector, an intermediate conduction layer formed between the at least one cavity cooler and the at least one accelerator cavity configured to facilitate thermal conductivity between the cavity cooler and the accelerator cavity, a mechanical support connected to the accelerator cavity via at least one endplate and configured for stabilizing the accelerator cavity, and a refrigeration source for providing refrigerant via the cooling connector to the at least one cavity cooler.

An accelerator comprising at least one accelerator cavity, an electron gun, at least one cavity cooler configured to at least partially encircle the accelerator cavity, a cooling connector, an intermediate conduction layer formed between the at least one cavity cooler and the at least one accelerator cavity configured to facilitate thermal conductivity between the cavity cooler and the accelerator cavity, a mechanical support connected to the accelerator cavity via at least one endplate and configured for stabilizing the accelerator cavity, and a refrigeration source for providing refrigerant via the cooling connector to the at least one cavity cooler.