The Need

Experiments performed at cryogenic temperatures much below the 4.2 K of liquid helium frequently require superconducting coaxial cables to efficiently transmit high frequency signals while minimizing heat transfer to the experiment’s cold stage. These cables are most often made of niobium-titanium alloy (NbTi) which is virtually impossible to directly solder. Two methods of using RF crimping or copper sleeves have been developed, but the current solutions do not allow for quality electrical connections to the superconducting coax or are expensive with long lead times. A fast and inexpensive technique is needed to produce a connector attachment matching the structural and electrical properties of standard coaxial cables.

The Technology

Kyle DeBry and Dr. Gregory Lafyatis of The Ohio State University have developed a new electroplating procedure for plating NbTi coax directly with copper, which enables connector attachment matching the structural and electrical properties of standard coaxial cables. The procedure has modest safety requirements, can be completed within ten minutes, and may be carried out in a standard vented laboratory fume hood. The connector-cable junction also meets the military specification MIL-PRF-39012E for mechanical and electrical RF performance. While the procedure was developed with SMA and SMP connectors, this method should be readily usable for connecting any type of RF cable connector to any NbTi conductor.

Commercial Applications

• Superconducting magnets
• Attaching RF connectors to NiTb superconducting coax

Benefits/Advantages

• Quick attachment of connectors to superconducting coax
• Inexpensive
• Meets military RF specifications