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.

Single-strand cryogenic wire — WSL-32, WSL-36

Phosphor bronze wire
Non-ferromagnetic
Single strand
32 and 36 AWG
Polyimide insulation (WSL-32)
Formvar® insulation, clear (WSL-36)

Lake Shore non-magnetic (NM) single lead (SL) wire is a phosphor bronze (CuSnP alloy) wire. This wire has a relatively low temperature dependence of its resistance from room temperature to helium temperatures. WSL-32 can be used for sensor installations requiring stronger and more “rugged” leads. WSL-36 wire is recommended for general sensor installation.

Twisted lead wire — WCT-34

Silver-plated copper
34 AWG
Teflon® insulation

These low-resistance twisted-pair wires are ideal for extending the lead length of Lake Shore cryogenic Hall sensors.

Duo-Twist™ cryogenic wire — WDT-32, WDT-36

Phosphor bronze wire
Non-ferromagnetic
Single twisted pair (2 wires)
Color-coded (cathode-green, anode-clear)
Minimizes pickup noise
32 and 36 AWG
Polyimide insulation

Duo-Twist™ is a single twisted pair (2 leads) of 32 or 36 AWG phosphor bronze wire twisted at 3.15 twists per centimeter (8 twists per inch). This wire is a good choice when any possibility of pickup noise to a diode sensor or sample by induced currents through the leads needs to be minimized.

Quad-Lead™ cryogenic wire — WQL-32, WQL-36

Phosphor bronze wire
Non-ferromagnetic
Four color-coded leads
32 and 36 AWG
Polyimide insulation

Quad-Lead™ wire is a 4-wire “ribbon cable,” which makes heat sinking and dressing leads much easier than working with individual wires. Noninductive (bifilar) windings are simple to make for heat sinks and heaters using the Quad-Lead™ wire. In addition, the wire is color coded for easy lead identification and can be split to yield 2 wire pairs. Quad-Lead™ wire is also useful in standard 4-lead measurements in magnetic field applications due to its low magnetoresistance.

Note: Quad-Lead™ wires are formed into a “ribbon cable” using Bond Coat 999 bonding film. This bonding agent will soften above 160 to 180 °C. Individual wires can be separated either by heat or with a rotary-abrasion style mechanical stripper (recommended: Eraser company RT2S Magnet Wire Stripper). Do not separate the wires using any kind of sharp blade, as damage will result. For more info, download Separation of Quad-Lead™ Wires.

Quad-Twist™ cryogenic wire — WQT-32, WQT-36

Phosphor bronze wire
Non-ferromagnetic
2 twisted pairs (4 wires), color-coded
Minimizes pickup noise
Polyimide insulation (WQT-32)
Formvar® insulation (WQT-36)

Quad-Twist™ is 2 twisted pairs (4 leads) of 32 or 36 AWG phosphor bronze wire. Each pair incorporates 3.15 twists per centimeter (8 twists per inch), and the 2 pairs are entwined at 1.57 twists per centimeter (4 twists per inch). This wire is a good choice when pickup noise to a diode sensor or sample by induced currents through the leads needs to be minimized. Use one twisted pair for sensor excitation and the other twisted pair for sensor output voltage to minimize pickup of electromagnetic noise.

Manganin wire — WMW-30 , WMW-32, WMW-36

Nominal 83% copper, 13% manganese, and 4% nickel
Non-ferromagnetic
30, 32, and 36 AWG
Heavy Formvar® insulation

Lake Shore manganin wire is often used for cryostat wiring or heater requirements in nonmagnetic applications.

Heavy-duty lead wire — WHD-30

30 AWG
Seven 38 AWG silver-plated twisted copper strands
Black etched Teflon® for adhesion to epoxy

This more rugged wire is useful as a lead wire to resistance heaters in cryogenic environments where low resistance to the heater is required or desired.

Nichrome heater wire — WNC-32

Nominal 80% nickel, 20% chromium
Non-ferromagnetic
32 AWG
Polyimide insulation

This high-resistance wire is typically used for heater requirements. The relatively large wire size provides sufficient surface area to dissipate the heat generated within the wire with only a moderate rise in wire temperature. (Note: We have had poor experience with heaters made using wire smaller than 32 AWG and supplying 25 W or more power; a possible alternative is one of the Lake Shore cartridge heaters.)