



Twisted Pair Wiring
Measurement Infrastructure
Bluefors offers high-quality Twisted Pair Wiring for direct current (DC) measurements integrated into the cryostat.
Twisted Pair Wiring is available in sets of 12 pairs (24 wires). All wires are factory-twisted and then bundled in fiberglass sleeving for protection.
To guarantee cryogenic performance, all DC wiring is tested at room temperature (RT) and at nitrogen temperature before integration.
Finally, the integrated DC wiring is tested while the system is at base temperature. At every temperature stage, the bundle is thermally anchored on gold-plated copper bobbins.
One KF40 LOS-port can fit up to 4x sets of 12 twisted pairs.






Product Highlights
1.0
Twisted Pair Wiring
Measurement Infrastructure
Easy Assembly and Maintenance
The modular structure of Twisted Pair Wiring enables easy assembly and maintenance of the wiring infrastructure. A single bundle can be changed without disassembling the entire system.
High Quality Connectors
The micro-D connectors used at low temperatures have been thoroughly tested to ensure high quality and reliability.
Wiring Solutions Based on Experimental Need
Wiring solutions can include different options – for example, additional breakouts, adapters, or additional cable length. With these options, wiring solutions can be optimized based on experimental needs.
Technical Specifications
2.0
Twisted Pair Wiring
Measurement Infrastructure
At room temperature (RT), each set terminates in a hermetic 24-pin Fischer connector.
At low temperature stages, the wiring terminates in a 25-pin micro-D connector. The low temperature termination can be used as a breakout post (screwed to the experimental flange with an included gold-plated copper mounting bracket) or as a connector to be plugged directly into, for example, a filter or sample holder box.
The standard materials for Twisted Pair Wiring are shown below. For more detailed information contact our Sales team for a copy of our Wiring Catalog.
Note: Includes additional thermal anchoring bobbin stages to pulse tube.
Wire consists of two sections: copper wires from RT to 4K and superconducting wires NbTi/CuNi from 4K to MXC.
Note: Includes a 25-pin micro-D breakout connector below 4K Flange.
Together with Attocube, we have developed a special low-ohmic cable for their positioners and scanners. This set is not based on superconducting wires and can be used to operate the Attocube devices also at room temperature (positioner wire resistance < 5 Ohm). The length can be configured to each temperature stage. Standard lines include 1–3 pairs for drive lines and 4–12 pairs for other uses.
Note: Includes an additional thermal anchoring stage to the pulse tube.
Options
3.0
Twisted Pair Wiring
Measurement Infrastructure
The TWP cable can have additional 25-pin micro-D connector breakouts at any flange to make the installation of customer devices easy. In the standard installation, the micro-D connector termination from the higher temperature serves as a breakout post and it mates with the micro-D connector termination of the continuing TWP wiring cable.
Our TWP cables can be equipped with the electromagnetic (EM) shielding. We have a solution where we use a stainless-steel sleeve around the wires together with a shielded housing for the micro-D connectors.
Note: The shielding is not available for Attocube wiring.
The QDevil‘s QFilter is a compact multi-stage low-pass filter with 24 lines. It rejects noise and ensures lowest possible electron temperatures in the lines going to your quantum electronics devices. This filter concept originates from Harvard University and the University of Copenhagen.

A QFilter contains two filter banks, one with RC circuits and one with LC circuits. For filtering 24 lines these two banks are connected in series using a short jumper cable. For filtering 48 lines, the QFilter can be pigtailed without the use of the jumper cable.
Note: The QFilter is not available for Attocube wiring.
DC Installation Set
4.0
Twisted Pair Wiring
Measurement Infrastructure
The gold-plated copper bobbins are mounted on a DC Installation Set for proper thermalization. The DC Installation Set includes a hermetic feedthrough connector box at room temperature and one aluminum and four gold-plated copper thermal anchoring feedthrough flanges for the 50K, 4K, Still, Cold Plate, and Mixing Chamber stages.
Number of DC Installation Set feedthroughs for each port size:
| Port size | KF25 | KF40 | ISO-K63 | Side-loading |
|---|---|---|---|---|
| Feedthroughs | 1, 3 or 4 | 3 or 4 | 10 | 9 |
The standard port for the DC Installation Set is KF40, which can have a maximum of four feedthroughs. This means a maximum of 4 x 12 TWP (total of 96) DC wires per KF40 port.
Technical Requirements
5.0
Twisted Pair Wiring
Measurement Infrastructure
All the Twisted Pair Wiring bundles are installed into a free port with the DC Installation Set.
SD
Free KF25 port or KF40 port for installation. If low-ohmic or copper wires are chosen, please make sure that there is space around pulse tube to install the pulse tube clamping.
LD
Free KF40 port or ISO-K63 port for installation. If low-ohmic or copper wires are chosen, please make sure that there is space around pulse tube to install the pulse tube clamping.
LD400sl
Free KF40 port for installation (installation to a side-loading port also possible). If low-ohmic or copper wires are chosen, please make sure that there is space around pulse tube to install the pulse tube clamping.
XLDsl
Free KF40 port for installation (installation to a side-loading port also possible). If low-ohmic or copper wires are chosen, please make sure that there is space around pulse tube to install the pulse tube clamping.
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