Helium cryostat 4 K sample in exchange gas OptistatCF continuous flow helium cryostat, sample in exchange gas ideal for experiments requiring high sample throughput and low conductivity samples.

  • Wide temperature range
  • Quick sample change in less than 5 minutes via top-loading sample probe
  • Superb optical access for measurements requiring light collection
  • Optimised clear beam throughput (15 mm diameter aperture) allows a large illumination area for measurements involving the detection of low intensity light
  • The most economical use of cryogens on the market: less than 0.55 L/hr at 4.2 K using a Low Loss Transfer tube
  • Versatile: wide range of sample holders/rods including liquid cuvette for liquid samples and precise height adjust/rotate sample rod
  • Compact size allowing easy integration into commercial spectrometers
  • Electrical measurements via 10-pin electrical feed wire to heat exchanger and/or wired on coax connectors
  • Can be operated in pull mode (using a gas flow pump to pull the helium from a storage dewar to the sample space) or push mode (by pressurising the storage dewar)
  • Two models to choose from: static or dynamic exchange gas


Model Static used in 'pull' mode Static used in 'push' mode Dynamic in 'pull' mode Dynamic used in 'push' mode
Temperature range 2.3 - 500 K* 4.2 - 500 K* 2.3 - 500 K*
1.6 - 500 K* in single shot
4.2 - 500 K*
Temperature stability ± 0.1 K (measured over 10 min period)
Maximum sample space 20 mm diameter
Sample holder dimension 19 mm wide x 30 mm long (optical sample holder version has a 15 mm aperture)
Cool down from ambient to 4.2 K (mins) 35


System Components/Options

A typical system consists of

  • OptistatCF helium cryostat
  • Sample holder and rod
  • Up to five sets of windows. (four radial; one axial); each set includes three windows (inner, radiation shield and outer case windows)
  • Cryogen transfer tube
  • Mercury iTC temperature controller
  • High vacuum pumping system
  • Helium dewar

Optional items

  • Gas flow pump
  • Gas flow controller
  • Automated transfer tube allowing fully automated control across the entire temperature range
  • Wiring and electrical connections to the sample
  • Simple height adjust and rotate sample rod: provides sliding adjustment with locking screws to hold a fixed position. The range of vertical motion is 32 mm; positioning accuracy is 0.5 mm( height) and 1 degree (rotation)
  • Precise height adjust and rotate sample rod provides height adjust and with a resolution of 10 µm and a goniometer for setting the rotation angle with a resolution of 12 minutes
  • Liquid cuvette for liquid samples

 Sample environment options

  • OptistatCF with static exchange gas: the circulating cryogen does not come into contact with the sample. The heat exchanger is in good thermal contact with the sample space which contains an independent exchange gas (usually helium). The sample is cooled by conduction through the exchange gas
  • OptistatCF with dynamic exchange gas: temperature stabilised cryogen flows into the exchange gas space cooling the sample directly. This version is recommended for large low conductivity samples or when large heat loads are applied to the sample. Also the cryostat can be used in single shot mode. The sample space is then filled with helium and pumped enabling a base temperature of 1.6 K for approximately 20 minutes (using an EPS 40 pump)
  • If you require a vacuum sample environment then please visit the OptistatCF-V web page. 

Window options

  • A wide range of window materials can be fitted to the OptistatCF to meet specific spectroscopy applications
  • Special windows with non-parallel faces and anti-reflection coatings are available
  • Additional or replacement window flanges available via the Oxford Instruments Direct - Cryospares® online catalogue

Pump options

  • A simple oil-free vane pump GF4 is supplied for operation to 3.4 K
  • Lower temperatures to 2.3 K require an EPS40 single stage rotary pump; this also extends the base temperature for the dynamic exchange gas version to 1.6 K

Transfer lines

  • Oxford Instruments Low Loss Transfer tubes (LLT) use the cold gas exiting the cryostat to cool the shields surrounding the incoming liquid within the transfer tube. As a result, the consumption of our cryostats is the lowest on the market, dramatically reducing your running costs
  • We can also offer an extra flexible transfer tube for those with restricted space in their labs. Please note that as this does not use the gas cooled mechanism, helium consumption will be higher than for the LLT range. However it will be well suited to those who need a lightweight and more flexible transfer tube
  • An auto needle valve can be fitted to the LLT which allows the temperature controller to optimise the helium flow rate



The OptistatCF works on a continuous flow principle using an oil-free pump to draw liquid helium from a storage dewar, along a transfer tube, to the heat exchanger ("pull" mode).

The cryogen is regulated by a needle valve on the transfer tube.

If the noise and vibration from the pump are undesirable then helium liquid can be pushed through the heat exchanger by pressurising the storage vessel ("push" mode).

The advantage of the pull mode operation is that the storage dewar pressure does not need to be monitored (since it remains at 1 atmosphere), the cryostat can reach a lower base temperature and the helium flow stability is improved. The advantage of the push mode operation is that the need for a gas flow pump is removed thus saving cost and eliminating the noise and vibration generated by pressurising the storage dewar.

Temperature control is achieved by a combination of manual helium flow control and power dissipated in an electrical heater, regulated using a temperature controller. The temperature is monitored by a rhodium iron temperature sensor fitted on the heat exchanger. To monitor the temperature at the sample position, an extra temperature sensor can be fitted at the sample position.

Changing the sample simply involves removing the sample rod, maintaining over-pressure of the exchange gas, replacing the sample and inserting the sample rod back into the cryostat. There is no need to break the insulating vacuum or warm the cryostat up. The resulting sample change times are very short, typically few minutes.

Related Products

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.

Mercury Support

Mercury Support

Support website for customers using MercuryiTC temperature controller and MercuryiPS magnet power supply.

Watch our latest webinar On Demand to find out ‘How Ion Beam Deposition enables high power lasers’… https://t.co/0z7DkZh0LQ
11:45 AM - 23 Mar 18
View more of our tweets