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Nanostructure research typically requires a highly stable sample platform. In addition to traditional liquid helium-based (wet) systems, Cryomagnetics offers systems based on the C-Mag magnet platform which allows for the convenience of 4.2K pulse-tube cooled superconducting magnet systems with variable temperature sample operation.

Cryomagnetics’ nanostructure research systems incorporate significant vibration isolation features to insure this stability. A single, low vibration 4.2K pulse-tube cryocooler is used to cool both the superconducting magnet and the sample. The cryocooler is installed using edge-welded vibration isolation bellows and ultra-flexible thermal straps inside the system. A vibration-isolation base stand is used to reduce transmission of floor vibrations into the system. The stand is compatible with extremely low vibration isolation mounting legs used in high resolution NMR applications requiring ultra-low vibration. Further vibration reduction options can include a remotely-mounted cold head motor. For probe microscopy methods an optional pneumatically dampened anti-vibration sample rod platform is available. The sample rod mounts to this platform via standard KF fitting and is linked to the magnet cryostat via a supple edge welded bellows assembly to minimize transfer of mechanical vibration.

The system includes a top-loading VTI integrated into the cryostat/cryocooler assembly. This provides the user with variable temperature access to the high field region of the magnet. The insert is very versatile, allowing for future upgrades of the system to extend the low temperature range of the sample space.

The refrigeration system is closed-loop and works as follows: A circulation of helium gas is brought into the system and cooled by the cryorefrigerator until it condenses to liquid He4. This liquid is then distributed to cool the magnet and VTI. Cooling of the VTI takes place through a JT expansion valve, thereby allowing samples to be cooled to as low as 1.5 Kelvin. After the helium is used to cool the sample, it exits the system and is then re-introduced (via a pump/compressor arrangement) back into the system where the process is repeated. Under normal circumstances, it is not necessary to refill helium after the initial charge.

The sample space is nominally 49mm in inside diameter. By increasing the sample space to 49mm, Cryomagnetics is able to offer optional inserts and upgrades that provide even lower base temperatures while still maintaining a large 25mm diameter sample space.

Available in vertical or horizontal (split pair) single axis or 2 or 3-axis vector configurations, the cryostat and VTI may be configured in traditional or optical designs which feature horizontal and bottom mounted windows to match research objectives.  Optical designs feature interchangeable quartz windows which may be exchanged as needed based on wavelength requirements.

The outer vacuum casing of the system and the intermediate thermal shield are modular and sealed using o-rings. This makes the system very versatile. Modifications can be easily made, and should system service ever be required, it can be done without cutting any metal on the system.

The VTI will be equipped with a sample probe. The sample mount is gold-plated OFHC copper and includes a heater and calibrated (1.5K-325K) temperature sensor.

The system may be upgraded to include a He3 insert which allows for extended to continuous operation at <350mK or lower depending on configuration and He3 volume.

All Cryomagnetics’ nanostructure research systems include a gas handling system (GHS). It will be equipped with a vacuum pump, a compressor, a helium gas expansion chamber, and all necessary valves, gauges, and plumbing necessary for operation of the system.

To simplify superconducting magnet operation, Cryomagnetics’ nanostructure research systems will include Navigator™ software. Navigator is a LabVIEW-based software package that allows complete automation of the superconducting magnet system control electronics.

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