


XLDsl System
Dilution Refrigerator Measurement System
The XLDsl Dilution Refrigerator Measurement System is designed for demanding experiments that require large experimental space, extensive wiring, and superior performance.
The XLDsl accommodates up to 1008 factory-installed semi-rigid 18 GHz coaxial lines in a configuration with two pulse tubes. Its side-loading feature allows experimental wiring to be prepared away from the cryostat while the system is running.
Even with its extensive capabilities and superior performance, a fully automated cool-down sequence from room to base temperature can still be carried out at the push of a single button.






Product Highlights
1.0
XLDsl
Dilution Refrigerator Measurement System
Side-Loading Enables the Fast Exchange of Wiring
The side-loading feature allows wiring assembly work for the installation set flanges to be performed on a workbench away from the cryostat. Consequently, the preparation of a wiring assembly or a full experiment can be performed while the system is running. When the system is warmed up to room temperature, the assembly can be immediately exchanged, greatly reducing the room temperature idle time.
Preparing and exchanging the installation set assembly is carried out using a dedicated installation tool that provides the mechanical stability and maintains correct spacing between flanges when the assembly is not mounted into the cryostat.
Enhanced Cooling
We have developed a solution to optimize the integration of pulse tube cryocoolers in our dilution refrigerators to increase their cooling performance. This redesigned integration results in a significant increase in cooling power at the 4K flange. The improved pulse tube cryocooler integration also makes it possible to operate the 4K flange at a higher temperature without affecting the dilution unit. Elevated 4K flange temperatures generate a significant increase in available cooling power.
Learn more about enhanced cooling
Extensive Experimental Wiring Capabilities
The XLDsl System features a variety of access ports between the Room Temperature and the Mixing Chamber Flanges, the primary ports being the six side-loading line-of-sight (LOS) ports for experimental wiring.
- 6 x Side-loading ports (LOS)
- 3 x KF40 (LOS)
- 4x KF40
The side-loading system is compatible with our High-Density Wiring options. High-Density Wiring is a modular option for the XLDsl dilution refrigerator measurement system that enables high scalability for the experimental wiring, especially for high-frequency signals.
Read more about High-Density Wiring
Vast Experimental Space
Mixing Chamber Flange Diameter: 500 mm | 20″
A centrally-placed unit distributes the cooling evenly around the Mixing Chamber Flange. The open design permits easy experiment access without the heat exchangers or system support structure obscuring access.
Superior Performance
- Base temperature below 10 mK
- Cooling power: >30 µW at 20 mK
- Cooling power: >1000 µW at 100 mK
See all technical specifications
Temperature Controller
The Bluefors Temperature Controller enhances the user experience of our cryogenic systems. With a modern and intuitive user interface, you gain direct control and overview of the system’s temperature status.
The Bluefors Temperature Controller is fully integrated to all dilution refrigerator measurement systems.
Read more about the Temperature Controller
Low Total Cost of Ownership
Oil-free pumps and compressors in the Gas Handling System guarantee minimal maintenance requirements with a service interval up to 3 years. The systems contain only high-quality components such as Pfeiffer Vacuum pumps and pressure sensors, VAT vacuum valves and bellows.
Gas Handling System & Control Software Generation 2
Technical Specifications
2.0
XLDsl
Dilution Refrigerator Measurement System
Note: Cooling power is measured from experimental flange outside the Mixing Chamber. Cooldown time to base temperature is measured from an empty system with standard experimental space and shield set.
| XLD1000sl | Guaranteed |
|---|---|
| Base temperature | 10 mK |
| Cooling power at 20 mK | >30 μW |
| Cooling power at 100 mK | >1000 μW |
| MXC Flange Diameter | 500 mm |
| XLD450sl | Guaranteed |
|---|---|
| Base temperature | 10 mK |
| Cooling power at 20 mK | >14 μW |
| Cooling power at 100 mK | >450 μW |
| MXC Flange Diameter | 500 mm |
Pulse Tube Cryocooler Configurations
3.0
XLDsl
Dilution Refrigerator Measurement System
Cryomech Pulse Tube Cryocoolers with remote motors provide cryogenic cooling power to the dilution refrigerator measurement system without the need for liquid cryogens. The cooldown time of the system partly depends on the selected pulse tube power and the upgraded pulse tube models provide increased cooling power at the 4K Flange. See available cryocooler models in the table below.
Enhanced Cooling
We have developed a solution to optimize the integration of pulse tube cryocoolers in our dilution refrigerators to increase their cooling performance. This redesigned integration results in a significant increase in cooling power at the 4K flange. When systems with enhanced cooling are operated at 3 K, the available cooling power at the 4K flange doubles. With the enhanced PT425-RM & PT310-RM combination, the XLD1000 now has ~700 mW of available cooling power at the 4K flange at 3 K.
The improved pulse tube cryocooler integration also makes it possible to operate the 4K flange at a higher temperature without affecting the dilution unit. Elevated 4K flange temperatures generate a significant increase in available cooling power. With the enhanced PT425-RM, the XLD1000sl System can now provide ~2000 mW of available cooling power at the 4K flange while operated at 4.5 K – tripling the amount of cooling power. Learn more about enhanced cooling here.
The PT310-RM configuration also provides 10% increase in MXC Flange cooling power. Learn more here.
| Pulse Tube Cryocooler Configuration | XLD450sl | XLD1000sl |
|---|---|---|
| PT425-ENH x 3 * | – | Available |
| PT425-ENH & PT310-ENH | Available | Available |
| PT425-ENH x 2 | Available | Available |
| PT415-RM-ENH x 2 | Default | Default |
Options
4.0
XLDsl
Dilution Refrigerator Measurement System
Note: XLDsl has configurations with two or three Pulse Tube Cryocoolers. The Additional 4K Flange option requires the third Pulse Tube Cryocooler integration. Still Heat Pipe is always included in XLDsl systems.
Faster turnaround options
Frame Options
Shield options
Gas Handling System options
Other options
Performance Graphs
5.0
XLDsl
Dilution Refrigerator Measurement System

Figure above shows the cooldown curves for a configuration of an XLD1000sl System with dual PT420-RM pulse tubes, 625 mm sample space height, without Mixing Chamber Shield, 168 High-Density Wiring, and 25 coax lines to 4K Flange.

Figure above shows the cooldown curves for a configuration of an XLD1000sl System with dual PT420-RM pulse tubes, 625 mm sample space height, with Mixing Chamber Shield, and minor wiring.
Pulse Pre-Cooling sequence is one of the key points in reducing the cooldown time (see spots 2 and 3). Because we do not use exchange gas some parts of the dilution refrigerator unit stay ‘hot’ on cooldown, which prevents condensation of the mixture. To cool down these hot spots effectively, the mixture is repeatedly admitted from the tanks to the Still side of the dilution refrigerator to operate as an exchange gas and then pumped out again.

Above are cooldown curves for two different configurations of XLD450sl systems measured with calibrated resistance thermometers.
- System 1: basic XLD450sl with 75 coaxial lines and 144 DC lines.
- System 2: XLD450sl with extra space, Mixing Chamber Shield, and additional sample mounting plate.
Pulse Pre-Cooling sequence is one of the key points in reducing the cooldown time (see spots 2 and 3). Because we do not use exchange gas some parts of the dilution refrigerator unit stay ‘hot’ on cooldown, which prevents condensation of the mixture. To cool down these hot spots effectively, the mixture is repeatedly admitted from the tanks to the Still side of the dilution refrigerator to operate as an exchange gas and then pumped out again.
Related Products
Layout and Facility Requirements
6.0
XLDsl
Dilution Refrigerator Measurement System
Layout Overview

Each Bluefors system is designed to be installed to a specific location defined in advance. A separate layout drawing is made for each Bluefors system, which should always be referred to for exact dimensions.
Facility Requirements
The basic requirements are 3-phase electricity, cooling water, and compressed air. The full list of requirements and specification details can be found in the Pre-Installation Guide, please contact our sales team for a copy.
See Also
Increased Cooling Power Specifications for Bluefors Dilution Refrigerators
New Products: Enhanced Cooling, High-Density Flex Wiring, and LD450sl
Gas Handling System Gen. 2 – Designed for Performance
Control Software Generation 2 – Cool Power at Your Fingertips
Cryomech PT310-RM Integrated Into Bluefors Dilution Refrigerators
First Generation 2 Systems Installed at the University of Copenhagen
1000th Bluefors system has been installed
Quantum Applications in the Bluefors Measurement System
How Does a Dilution Refrigerator Work?
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