Superconducting Magnet Systems

7T-CF-ST-500 Microscopy Superconducting Magnet System

Standard system features:

  • Top sample loading and exchange at all temperatures
  • Effortless sample rotation and translation about the vertical axis at all temperatures, with options for rotation about a horizontal axis
  • Field-independent thermometry
  • The SuperVariTemp system, with provision for a temperature control thermometer at the heat exchanger
  • Vapor cooled/superconducting high current magnet leads
  • Superconducting magnets with persistent mode operation providing field stabilities of 20 ppm/h
  • Carefully designed magnet support inside the helium reservoir, with optical access through the Dewar vacuum space (OptiMag and SuperOptiMag systems)
  • Built-in superconducting liquid helium level sensors, providing continuous or timed level monitoring
  • Readily accessible and interchangeable sample chambers

Complete systems include:

Lake Shore — environment by JANIS
 ModelSample environmentOperating temperatureMagnetic fieldOptical access
He-4 systemsSuperVariMagFlowing helium vapor or vacuum/UHV1.5 K to 325 K (options to 400 K)6 to 12 TNo
OptiMagFlowing helium vapor or vacuum/UHV1.5 K to 325 K6 to 12 TYes
SuperOptiMagFlowing helium vapor or vacuum/UHV1.5 K to 325 K7 TYes
Room temperature bore systems*Atmospheric pressure or vacuum/UHV300 K6 to 12 TYes
Special systemsMicroscopyVacuum/UHV3.5 K to 450 K0 to 7 TYes
Cryogen-freeVacuum/UHV or exchange gas1.5 K to 700 K0 to 12 TYes
Vector magnetsVacuum or helium vapor/liquid1.5 K to 800 K5 to 12 TYes

*Room temperature bore systems can be combined with variable temperature cryostats to operate in temperature ranges between 1.5 K and 800 K.

With over four decades of experience and a worldwide installation base, we are a recognized leader in the design and manufacture of superconducting magnet systems. Our renowned SuperVariTemp insert operates from 1.5 K to 325 K, and is featured in the SuperVariMag, OptiMag, and SuperOptiMag systems and is also available as an independent insert for use with existing magnets. We also offer a variety of superconducting magnet systems that offer a room temperature bore (with inserts that reach 800 K) along with a variety of other systems that are designed for specific applications. These state-of-the-art systems feature integrated designs for the cryostat, magnet, temperature controller, and programmable power supply, together with a complete line of ancillary equipment. Janis Research's approach to superconducting magnet system design provides a variety of technical and cost benefits.

By maintaining flexibility over the specification and integration of the magnet, electronics, temperature controller, and cryostat, we are able to offer magnet systems with performance characteristics tailored to individual experimental and budgetary requirements.

Our staff of physicists and engineers has extensive experience in the design and operation of superconducting magnet systems and are uniquely qualified to assist you with every step of your system purchase, from experimental design to post-installation support. All systems are fully integrated and liquid helium tested at our Woburn, Massachusetts facility; installation, start-up, and training are available.


This magnet requirements questionnaire contains several questions that will help our engineers determine the best system for your requirements. Please take a moment to fill it out and email it back to

Independent SuperVariTemp inserts

Superconducting Magnet SVT Insert

The Lake Shore SuperVariTemp (SVT) cryostat is a key component of all SuperVariMag, OptiMag, and SuperOptiMag systems. By controlling the temperature of the flowing helium vapor in which samples are immersed, the SVT allows for precise monitoring and control of sample temperature over a 1.5 to 325 K range, while eliminating the need for thermal anchoring and sample mount heating. The helium flow rate and heater are balanced to provide operation over the range of 4.2 K to 325 K; automatic temperature controllers equipped with field-independent thermometers provide accurate and precise temperature control.

The SVT cryostat allows full use of the cooling power of escaping helium vapor as it exits the sample chamber. The sample chamber is thermally isolated from the helium reservoir by the Dewar vacuum, thereby eliminating heat conduction into the reservoir. Precise sample temperature is measured through the use of a thermometer attached to the sample holder. Operation to 1.5 K is made possible by immersing the sample in liquid helium and reducing the pressure with a mechanical vacuum pump. The SVT's unique design also allows sample cooling in flowing helium vapor to approximately 2 K for extended operation below 4.2 K without the need to monitor or replenish the helium level in the sample chamber. For optical experiments, this presents the least interference to the incoming and scattered beams.

The SVT insert is available as an accessory for existing superconducting magnets. A custom-designed SVT cryostat can be matched to the dimensions of an existing open neck Dewar and magnet bore. Drawing liquid helium from the main magnet reservoir, the SVT insert will provide temperatures of 1.5 K to 325 K without the need for pumping on the main reservoir.

It is also available in a high-stability or a high-temperature static gas insert option for applications requiring a high stability region, continuous operation above 100 K, for high sensitivity experiments that preclude locating the sample in a flowing helium vapor. Special sample positioners can also be supplied for temperatures of 400 K or higher along with optional wiring and cold, detachable wiring stages.