The TritonXL Cryofree® dilution refrigerators, specifically designed for quantum computing

The TritonTMXL range of dilution refrigerators enables higher cooling power, more sample space and achieves colder base temperatures than any other Cryofree dilution refrigerator on the market (3.3 mK has been demonstrated). TritonXL comes with two different dilution units based on the choice of base temperatures and cooling power:

  • TritonXL 1000 with a guaranteed base temperature of < 5 mK (< 4 mK expected) and cooling power of 1000 µW at 100 mK
  • TritonXL 400 with a guaranteed base temperature of <7 mK (< 6 mK expected) and cooling power of 400 µW at 100 mK

Typical performance of TritonXL 1000:

  • Less than 4 mK base temperature
  • 5 µW of cooling power at 10 mK
  • 25 µW of cooling power at 20 mK
  • Up to 1000 µW of cooling power at 100 mK (depending on the choice of pulse-tube cooler)
  • 430 mm diameter mixing chamber sample plate
  • Accepts up to two 1.5 W pulse tube refrigerators
  • 100 mm central line of sight port for semi-rigid coaxes or a top loading exchange mechanism
  • Six 50 mm line of sight ports for semi-rigid coaxes
  • Five 50 mm non-line of sight ports for flexible wiring
  • Integrates magnets up to 18 T
  • A total of up to 70 semi-rigid coaxes with SMA connectors can be installed











Download the TritonXL brochure here.

TritonXL specifications


  • Base temprature:  < 7 mK for TritonXL 400 and < 5 mK for TritonXL 1000
  • Cooling power at 20 mK: 8 µW for TritonXL 400 and 25 µW for TritonXL 1000
  • Cooling power at 100 mK: 400 µW for TritonXL 400 and 900 µW for TritonXL 1000
  • Cool down time: < 48 h
  • Sample environment: vacuum
  • Sample space: 430 mm diameter x 400 mm
  • Top and bottom sample loading options
  • Selected magnet options: up to 18 T

To view the full specifications, download the specfications sheet below.

TritonXL features

Easy access to sample region

The large and open structure of the Triton platform makes it easy to install additional equipment on the experimental plates.

The mixing chamber plate can support an experimental mass of up 10 kg in its standard configuration. It can also be reinforced to suit even heavier experiments should it be required. The 4 K plate (PT2) can support an additional 60 kg of equipment.

Robust and proven dilution unit technology

The solid track record of the Oxford Instruments dilution unit is a result of several decades of work into perfecting the art of welding, brazing and soldering components for maximum reliability and leak-tightness.

This critical component is now used in more than 700 wet and dry dilution refrigerators worldwide – a larger installed base than all other vendors combined.

Low vibrations

The vibration amplitude has been measured on all experimental plates to 100 nm or less across the frequency spectra from 1 Hz to 1 kHz. This is achieved with two important features: the use of highly flexible copper braids, which decouple the pulse-tube heads from the experimental plates.









Temperature stability

Temperature control is critical for careful sample characterisation of any new material or device. The inherent base temperature stability of the system without an active temperature control feedback loop can be seen in this graph. The temperature measured was 8.3 ± 0.2 mK. In separate experiments, when over biasing the control sensor, the closed loop control of the system can be improved.

In the temperature range 20 – 300 mK, control better than 10 μK has been achieved. Also shown here is the measured mixing chamber temperature, whilst controlling the temperature at 30 K and simultaneously ramping an integrated magnet from zero field to 12 T and back to zero at 0.3 T/min. The standard deviation of the temperature measurements was 3.5 mK and the maximum deviations were approximately ± 7 mK.

Demountable impedance

Despite highly efficient cold traps, small amounts of contamination may accumulate after a few years of operation. The Triton design with easily accessible and demountable impedance on a standard VCR gasket fitting, makes it easy to change this component ,should it be necessary.

Cold traps

Internal charcoal traps operating at 60 K, is capable of adsorbing more than 1 L of air contamination.

The system can easily operate for more than 6 months without having to warm it up.

Long hold time of the LN2 dewar for the external cold trap, requiring only one top-up per week. Dewar with even longer hold time is available on request.


Professionally soldered sensors (4-wire read out) are installed on all five experimental plates with demountable connectors for ease of service. Sensors and heaters are operated using a Lakeshore 370AC bridge with a 16 channel scanner.

The mixing chamber RO2 sensor is cross-calibrated in the factory against a primary Co60 nuclear orientation (NO) crystal. Because resistance thermometry is sensitive to changing RF environment, we offer the calibration to be repeated during installation to confirm its accuracy.

Integrated gas handling system

The welded assembly with high performance, pneumatically controlled, bellow-sealed valves offer minimum risk of through leaks. Integrated pressure-relief valves protect against pressure build-up due to a power cut or cryogenic blockage. Switches allow for manual control of all pneumatic valves, without having to rely on the software (requires 5 bar compressed air supply).

Oil and dust free pumping circuit

The Pfeiffer HiPace turbo pump has magnetic bearings for minimum wear and an expected life time approaching 100,000 hours and is UL certified.

The Oxford Instruments model is optimised for helium gas to ensure the lowest possible still temperature.




Adixen dry multi-stage roots pump from Pfeiffer, is renowned for its high reliability in the semiconductor industry and is UL certified. Roots pump benefits from a higher pumping speed than many alternative pumps, which means less strain on the turbo pump.





Double-diaphragm compressor from KNF, a high specification version, developed specifically for Oxford Instruments. It is UL certified and capable of operating at very high outlet pressures of 4 bar, which provides extra safety in the event of a partial restriction developing in the cold section of the condensing line. Its unique double-diaphragm design offers an extra layer of protection against loss of mixture (absent in any other pumping technology). It is also a cleaner technology, for example, compared to scroll pumps, which generate dust from the tip seal.



Sample exchange for TritonXL

Bottom loading sample exchange

Sample space maximised 
Our best in class, patented, sample loading mechanism comes with a choice of 42 mm or 72 mm maximum sample space (ID of its radiation shield) to suit magnets with a bore size of 58 mm or 90 mm respectively. 
Fast cool down
These sample pucks cool from room temperature to base temperature in typically 7 hours and 10 hours respectively. The cool-down procedure is fully automatic using the system control software.
Superior temperature performance
Sample temperatures of 10 mK with multiple semi-rigid coaxes installed, can be achieved on both versions.
Superior wiring capacity
14 RF (40 GHz SMP) plus 50 DC connections is supplied as standard (provisions for up to 28 RF plus 100 DC connections are available on request). 
Additional connections going through the loading stick allows electrical contact with the sample during the loading process. These are useful for grounding or biasing the sample, before the puck docks with the connections on the mixing chamber.

Top loading sample exchange

Our top loader benefits from the same unrivalled performance as the bottom loading option.

Ease of use and larger sample space

The top loading mechanism (fitted to the central line of sight port) allows sample exchange with the cryostat installed in a pit or on top of an optical table. The clear diameter sample space is 32 mm.

Superior wiring capacity

8 RF (18 GHz BMA) plus 50 DC connections are supplied as standard (provisions for up to 24 RF connections with SMP connectors are available on request). Just like the bottom loader, additional DC connections going through the loading stick allows for grounding or biasing of the sample during loading.

Integrated cryogen free magnet for TritonXL

Award winning integrated cryogen free superconducting magnets and dilution refrigerators provide combined B/T environments, cooled by a single PTR

Our in-house manufacturing of both magnets and refrigerators enable us to offer unique service and support capabilities of all aspects of the system.

A wide range of solenoid magnets, ranging from 0.3 T to 18 T and a variety of multi-axis vector magnets and split-pairs with optical access, is available. Demountable current leads (as opposed to soldered) are available on request for the majority of magnets.

Our HTS current leads with a brass top section (as opposed to copper), reduce the heat load resulting from radiation and wiring services to the 4 K stage from 60 K.

Oxford Instruments is the only single source supplier, offering guaranteed integrated cryogen free magnet and dilution refrigerator performance with such an extended range:

  • 3, 5 , 8, 12, 14 and 18 T solenoids available as standard options
  • New magnet acceleration technology (see below)
  • Base temperature: ≤ 7 mK expected
  • HTS current leads for low heat dissipation between 50 K and 4 K
  • Fast ramping capability using the latest high field, low loss Nb3Sn developed by Oxford Instruments. Magnet ramps from zero to 15 T in less than 30 minutes
  • 70 mm cold bore standard on NbTi coils, 57 mm cold bore standard on Nb3Sn coils
  • 1 in 103 over 10 mm dsv homogeneity
  • 1 in 104/hr stability with persistent mode switch fitted
  • Custom designs, split pairs and vector rotate coils available on request
  • Automatic control of the dilution refrigerator from room to base temperature
  • Top or bottom loading options available for fast sample change
  • Easy and reliable sample access via only one O ring sealed vacuum space, no IVC
  • One single pulse tube cooler with vibration isolation at 4 K and 70 K

Cancellation coil

A cancellation coil which creates an actively shielded region (typically < 100 Gauss) around the mixing chamber plate is available for most solenoid magnets. This option results in a longer system cool down time but may be essential for experiments with magnetically sensitive components mounted on the mixing chamber plate. It also reduces eddy current heating, which makes it attractive for sweeping field experiments.


Magnet power supply

The new Oxford Instruments Mercury IPS builds on the success of our established power supply technology with a much improved user interface and added modularity. A 60 A master unit with a touch screen interface is combined with one or more 60 A slave units to provide higher currents and multiple outputs for 2 and 3 axis vector magnets. Built-in functionality for persistence mode control, quench protection and remote control via USB, TCP/IP, GPIB and serial ports, are some of the key features.



This image illustrates the integrated magnet warming and cooling during 5 T field sweep, hold at field and sweep back to 0 T (sweep rate 0.31 T/min). Local eddy current heating at the mixing chamber is also shown during field sweep, with time to recover back to base temperature being around 1 hour. 3 microwatt cooling power is available at 20 mK.


Optical windows for TritonXL

Optical windows

A wide range of standard and customised window configurations for detector applications has been developed for Triton.

A selection of cold and warm window materials with appropriate stress relief mounts to cope with thermal contraction are available, including Spectrosil B, Spectrosil WF, Sapphire, Quartz, Polypropylene and Mylar.





Remote control access software for TritonXL

Remote control access software for Triton

Triton cryogen free dilution refrigerators are controlled via a software, which allows system automation of refrigerator routines or programmable temperature/field sequences.

System automation:

  • Fully automatic cool down / warm up routines
  • Fully automatic pre-cooling / mixture collection
  • Sample change wizard for systems with load-locks
  • Fully integrated magnet control, including vector rotate magnet software

Experimental control:

  • Programmable temperature and field sequences
  • Programming library supplied with example LabVIEW VIs
  • Integration of dilution refrigerator / magnet control and experimental data acquisition

In-built safety features: 

  • Continuous monitoring of all pressure gauges
  • System automatically enters “safe state”, if necessary
  • Automatic software intervention in case of over pressure with fail-safe in-line pressure relief valves, protecting the mixture and dilution refrigerator in the event of extended power failures
  • UPS option – automatic alert emails can be sent to user in the event of a power failure
  • Monitoring of magnet temperature during field sweep, high temperature control, sample loading
  • Automatic magnet de-energisation in the event of power cut, pulse tube cooler failure, excessive heat load on second stage cooling

User support:

  • Detailed remote interface programming manual
  • Remote system access by Oxford Instruments support staff can be enabled to aid system diagnostics
  • Free software upgrades available for download from Oxford Instruments’ website
  • All system settings are backed up prior to shipping from the factory

Triton command interface:

  • Platform independent remote scripting interface
  • Standard internet (TCP/IP) protocol
  • Compatible with any programming language that can access the TCP port e.g., LabVIEW / Matlab / Python / C / C++ / C# / Visual Basic / HP VEE, etc.
  • Monitoring and control of automatic software routines and system parameters
  • Definable access levels (read only / read write, etc.) with security

Configuration and optional system upgrades for TritonX


Our UPS option is integrated with the Triton control software that ensures system logging and safety features are maintained and email notifications are sent. Shorter power blips result in a full system recovery. Extended power cuts result in the system being put in a 'safe mode', which simplifies recovery when power is restored. All systems with and without UPS are protected against pressure build-ups using mechanical pressure relief valves to allow the He3/He4 mixture back into the tank, without any software or manual intervention.



Warm up heaters

These high power heaters are mounted on four experimental plates together with the necessary protection circuit (thermal switches) and controlled with a Mercury ITC temperature controller. Apart from significantly shortening the warm up time, it also automates the procedure and avoids the use of Nitrogen exchange gas which may condense on the sample.



Wiring capabilities for TritonXL

One of the advantages of dry dilution refriegrators over wet dilution refrigerators is that there is more space available for customer wiring. The Triton offers 3 line of sight ports for high frequency coaxial lines or other custom services and 3 non-line of sight ports giving access for a variety of flexible wiring options.


Non-line of sight services

  • 24 way DC looms – Constantan or Cu/NbTi twisted pairs
  • S1 flexible coaxial lines – for use up to 500 MHz
  • Thermal clamping at PT1, PT2, Still, 100 mK and mixing chamber
  • Current leads for superconducting magnets
  • Wiring to suit commercially available nano-positioning devices
  • Custom services and optical fibres available

Line of sight services

The three line of sight ports available for high frequency coaxial lines or other custom services can be configured as two off KF40 and one off KF50 vacuum fittings, fully termintated for high frequency applications or blanked for customer fittings. In addition, a 65 mm central access LOS port is available for top loading sample access.

  • UT85 semi-rigid coaxial lines
  • Stainless steel inner / stainless steel outer conductor with PTFE insulation (UT85-SS-SS)
  • Beryllium Copper inner / stainless steel outer conductor with PTFE insulation (UT85-B-SS)
  • Niobium inner / Niobium outer conductor with PTFE insulation (UT85-Nb-Nb) from Still to mixing chamber
  • Heatsinking at PT1, PT2, Still, 100 mK and mixing chamber
  • SMA termination for frequencies up to 18 GHz
  • SK termination for frequencies up to 40 GHz
  • 20, 10, 6 dB attenuators at PT1, PT2 and Still plates available
  • Optional noise thermometry
  • Custom services and optical fibres available

Weak phonon-electron interactions at low temperatures make electron system cooling problematic in many applications. Fast pulse sequences for signal control is necessary in many areas of modern physics with corresponding high bandwidth wiring required. When working in the GHz frequency range, it is important to filter background blackbody radiation in the lines before it reaches the sample. Working with many of our customers, we have developed extensive high frequency wiring options with signal attenuation and heatsinking, to minimise electron temperatures on the sample or device.

  • Semi-rigid coaxial cables with frequency ranges up to 40 GHz
  • Heatsinking of outer conductor at all thermal plates
  • Heatsinking of inner conductor and filtering of blackbody radiation using attenuators

TritonXL technical support and service

Local technical support

Based at UK, USA, Germany, China, Japan and India, Oxford Instruments has a dedicated, qualified and experienced service team to support you with everything from installations, preventative maintenance, break fix, to general queries. You also have direct access to technical support from our magnet and cryogenics system engineers in our Oxford factory.

Service when you need it

Your Triton already comes with a full 3-year warranty (Triton Guarantee) covering the full system. For
even greater peace of mind for your planning and convenience, we offer the following service options –

Comprehensive service contract:

On-site preventive maintenance by an OI service engineer, priority access to spare parts from a service stock reserved for comprehensive service contract customers, as well as extended system warranty (if the Triton Guarantee has expired).

Preventative maintenance contract:

On-site preventive maintenance by an OI service engineer. We will service all pumps and compressors, update software/firmware and do a general health check of the system.

Preventative maintenance service kits:

Individual factory-serviced exchange pumps and compressor adsorbers are available to purchase as and when required. These service kits are installed by the customer in accordance with OI provided work instructions.

Extended warranty:

Covers your system beyond the standard 3 years Triton guarantee.

The Triton service brochure can be downloaded here.

Triton video - how to change your sample

Downloads and further information


Integration of superconducting magnets with cryogen free dilution refrigerator systems
Download the article here

A micro Kelvin Cryofree platform with noise thermometry
Download the article here

A rapid sample-exchange mechanism for cryogen free dilution refrigerators compatible with multiple high frequency signal connections
Download the article here

A new ultra low temperature cryogen free experimental platform
Download the article here

Triton in the news

Here you can find some recent news related to Triton:

See how Microsoft and Charlie Marcus lab are shaping the future of quantum computers with the use of an Oxford Instruments dilution refrigerator:

IBM scientists achieve critical steps to building first practical quantum computer:

Subatomic science highlights Raytheon's futuristic research:

Oxford Quantum, Quantum computers as learning machines:

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Product Support

Help Desk support

Help Desk support

A team is available to answer phone or email requests.

Installation and Service

Installation and Service

We can take care of the installation and maintenance of your product for complete piece of mind.

System Maintenance, Repair and Upgrades

System Maintenance, Repair and Upgrades

A full repair and maintenance facility is available; our dedicated technicians repair and service hundreds of systems per year.

Dedicated Spares and Accessories

Dedicated Spares and Accessories

Oxford Instruments Direct - Cryospares offers an extensive range of cryogenic spares, magnet spares, accessories and consumables - with a fast and efficient service, expert support and rapid delivery of products world-wide.

ServiceWise Contracts

ServiceWise Contracts

Service and maintenance contracts.

Extended Warranty

Extended Warranty

Extended warranty and PM including parts and labour. This contract allows you to safeguard your investment with complete peace of mind.

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