Cryogenic Wire |
Used to minimize heat leak into the sensor and cryogenic system, cryogenic wire has a much lower thermal conductivity (and higher electrical resistivity) than copper wire. The most common type of cryogenic wire is phosphor bronze. This wire is available in one-, two-, and four-lead configurations. Four-lead configurations are available as Quad-twist™ (two twisted pairs) or Quad-lead™ (ribbon). Wire gauge is 32 or 36 AWG, with polyimide or polyvinyl formal (Formvar®) used to insulate the wires. Other common cryogenic wires include manganin, nichrome heater wire, and HD-30 heavy duty copper wire. | More information on
Cryogenic Wire |
| | Solder |
The most common electrical connections are solder joints. Solder can also be used to install various sensors to improve thermal heat sinking. Common solders are indium solder and 90/10 Pb/Sn. Indium solder is used for various applications including sensor installation to provide excellent thermal contact with the sample. 90/10 Pb/Sn solder is used for applications requiring a higher temperature (liquidus point of 575 K and solidus point 458 K). Ostalloy® 158 solder is used as a seal for demountable vacuum cans and electric feedthroughs in cryogenic systems. | More information on
Solder |
|
Epoxy |
Epoxies are used to install and fasten sensors, while providing thermal contact and electrical insulation, with the sample. Epoxy can also be used for mechanical attachment and joints. Stycast® 2850FT is a black epoxy resin, and has a thermal expansion coefficient that is matched to copper. A silver-filled, low-temperature conducting epoxy provides excellent strength, along with electrical and thermal conductivity. | More information on
Epoxy |
| Grease |
Thermal greases are used to install and fasten sensors, while providing thermal contact and electrical insulation, with the sample. Apiezon N and Apiezon H greases are suitable for enhancing thermal contact, especially for sensors inserted into cavities. Apiezon N is for low temperature applications, while H is for high temperature. | More information on
Grease |
| Varnish |
The most common varnish for cryogenic installations is VGE-7031 varnish. It has good chemical resistance, bonds to a variety of materials, and has a fast tack time. | More information on
Varnish |
|
| |