Cryoconnect is a specialist division of Tekdata's Interconnect Systems, and deals solely with cabling and interconnection solutions in cryogenic systems. Whether you require high volumes or complex one-off cables, we are pleased to work closely with you to design and supply highly reliable solutions for all your cryogenic cabling needs.
Anyone involved in the supply or use of cryogenic systems needs highly reliable and well designed cabling.
… Wire types.
… Terminations.
… Thermal and electrical properties.
… Shields.
… Materials, geometries & characteristics.
… Controlling the geometry.
… Typical Insulation materials.
… Thermo-electric effects.… Feedthroughs.
… Heatsinks.
… RF filtering.
… Nano connectors in application.
… Installing Cryoconnect looms in systems.
… Heat sinking.
· What is Cryoconnect?
Cryoconnect is organized cryogenic wiring systems with your choice of:
· Wire types, co-axial cable, optical fibre woven into a convenient high strength aramid looms.
· Terminations encapsulated for added strength and reliability (e.g. connectors, PCB's & wiring feedthroughs).
· Wire configuration (e.g. twisted pairs, triples & quads which can be interleaved with shield wires or have selective shields in different sizes and types by design).
· Thermal and electrical properties can be determined with our design and support.
· Vacuum feed-throughs employing conventional hermetic connectors or our hermetic Cryoconnect wiring feed-throughs.
Cryoconnect looms and cable assemblies are:
· Robust, flexible, easy to install and heat sink.
· Available in any length.
· Discrete wiring with breakouts programmed into the weaving to address discrete components and thermometry.
· Shields with braided shielding in stainless steel and other metals by design.
Materials & Geometries & Characteristics.
· A Cryoconnect cable is a collection of wires and/or pre-made cables organized into an easy to handle and very strong planar structure using high strength aramid fibers.
· As well as utilizing resistance wires, we can configure cable assemblies with a wide range of cable types which include twisted pairs, triples, quads, with and without individual shields, co-axial cable and optical fiber.
· Cryoconnect technology allows us to integrate, in a single ribbon structure, primary wires and a wide range of pre-made cables of different types and diameters. This flexibility is unique and critical in reducing cable and connector count in complex systems.
· Controlling the geometry of our resistance wires we can provide looms with many different configurations. As an example, we configure twisted pairs with adjacent pairs twisted with LH and RH twists to minimise cross-talk and de-couple stray capacitance in adjacent pairs. We can supply parallel wires or wires in a sinusoidal weave for high speed. Ground wires may also be inserted between signal wires to control cross-talk.
In critical applications the separation of adjacent conductors may also be varied to allow control of the complex impedance of the loom.
· Controlling the impedance and bandwidth of resistance wires within the complicated geometry installed in a metal cryostat is not simple. In critical applications our experience and our ability to make trial looms to generate test data allows us to create the final application designs with the desired characteristics.
Cryoconnect is used in dilution refrigerators, cryogenic systems, superconducting magnet systems, low temperature detector systems, infrared array systems, and general housekeeping on cryogenic systems of all scales.
· Phosphor Bronze
· Nb/Ti with cupro-nickel coating.
· Stainless steel.
· Constantan.
· Manganin.
· Phosphor bronze.
· Brass.
· Aluminium.
· Copper.
· S1 coax (often woven into looms along with twisted pairs of resistance wires).
· Single or multiple twisted pairs inside braided shields of stainless steel or constantan.
· Polyester enamel.
· Pyre ML.
· PFA.
· FEP.
· FPI 205.
· PTFE.
· Kapton.
· We can also provide a range of additional insulations for both dielectrics and cable jackets upon request.
· Methods to minimize thermo-electric voltages vary dependent on application, for further information please contact us.
· Connectors vary from single pins to the ultra-miniature Nanonics connectors, MDM micro D types, sub-miniature D types, circular military style, co-axial connectors and Cryoconnect project specific designs. In certain configurations hermetic and RF filtered connectors are available.
· PCB transition boards and custom miniature connectors (e.g. for thermometry installation eliminating the need for a 'super harness) provide designers with additional flexibility.
· Heatsinks. In most applications heat sinking of wiring is important to avoid excess heat leak into the cryogenic system. Cryoconnect looms are easy to heat sink by wrapping the looms around cooling posts or installing along the length of support or vent tubes or with purpose built heat sinks which we can build and install on your looms.
Careful heat sinking is required where wires are expected to become supper conducting, or at ultra low temperatures where boundary resistance effects may make adequate heat sinking more difficult.
· RF filtering. Usually for cost effective RF filtering we recommend using RF filtered connectors with integral ground planes. In high connection count applications (e.g. hundreds of wires) the use of custom PCBs with appropriate RF filters and ground planes with PCB compatible connectors terminating the Cryoconnect cables. We also directly connect high density ribbons directly to PCBs using a variety of methods to strain relieve and secure.
· Nano connectors in application. We specialize in terminating high wire and shield counts into miniature connectors.
In the example shown the six 51 pin nano connectors have 450 signals on 150 manganin triples and 42 separate stainless steel braided shields.
· Installing Cryoconnect looms in systems. The use of woven looms to organize your wiring solution allows shear across the loom that makes installation in systems with complex geometry easy. Installation is simple around or in tubes, bends, and conical shaped sections. Minimum radii for the looms can be as low as 3mm, depending on wire diameter and insulation type.
· Thermal design. Design support is available to calculate the heat leaks of your cryoconnect cables, taking into account the contribution of the heat leaks due to high current in resistive wires.
· Magnetic fields. For operation in high magnetic fields (up to 5T) we recommend manganin, evanohm and annealed stainless steel for low magneto resistance and magnetic attractiveness.
· High Currents. Occasionally rather than measuring voltages or injecting low currents, relatively high currents are needed into cryogenic systems (e.g. to drive motors and magnets) and one needs to limit self heating in the wiring and at the same time minimise the passive heat leak down the wiring.
The Wiederman-Franz law relates the thermal conductivity of a wire to its electrical conductivity and solutions using resistance wire or a good electrical conductor such as copper or silver to give a low impedance for low self heating, will give similar passive (no current) heat leaks. In this situation, cable design needs to take into account various factors, including duty cycle, whether the system is cooled with liquid cryogen's where the enthalpy of the cold gas may be available to cool the wires, and whether hybrid solutions with high or low Tc superconductors can be used.
· The information and data given in the technical sections are provided as a general guide in designing Cryoconnect cryogenic cables and harness assemblies to give our clients some details of the wide range of possibilities that Cryoconnect looms provide.