The Janis ST-500 continuous flow cryostat has been specially designed for use in microscopy, imaging, and high spatial resolution photoluminescence. The combination of the low thermal-expansion support structure and internal vibration isolation results in nanometer-scale vibration and drift levels. The cryostat geometry offers a short working distance (for use with high magnification optics) and permits mounting on common microscope stages and translators.
Standard configuration
The ST-500 system includes a flexible high-efficiency variable flow cryogen transfer line. This line delivers liquid helium or liquid nitrogen to a two-stage heat exchanger and sample mount. The ST-500 is portable, easily mounted in a variety of configurations, and can be used both in transmission and reflection geometries.
Other configurations include:
- Ultra-compact
- Options for micro-spectroscopy techniques
- Sample extension for magnetic measurements
- Breakout box accessory for electrical measurements
- Ultra-high vacuum
- Superconducting magnet for high-resolution microscopy
- Micro-manipulated cryogenic and vacuum probe system for chips, wafers, and device testing
Options include:
- A variety of window materials and sizes
- Interchangeable sample mounts for different sample thicknesses
- Magneto-optical system (including optional rare earth magnets)
- Electrical and RF feedthroughs
- A complete system solution including temperature controllers, pumping systems, and storage Dewars
- Looking for a cryogen-free option for your existing ST-500? Optional recirculating gas cooler eliminates the use of liquid helium for “wet” systems.
Researchers around the world are using these systems to conduct research in a wide variety of fields, including MEMS, nanoscale electronics, superconductivity, ferroelectrics, material sciences, and optics.
ST-500 Specifications
| Temperature range | 3.5 to 475 K (standard) |
| Initial cooldown time | 10 K (LHe): 25 min |
| 80 K (LN2): 30 min | |
| Cryogen usage during cooldown to 4.2 K | 1 L LHe |
| 0.3 L LN2 | |
| Temperature stability (with temperature controller) | <50 mK |
| Weight (not including transfer line) | 7 lb (3.2 kg) |
| Nominal cryogen usage | LHe at 5 K: ~1.1 L/h |
| LN2 at 80 K: ~0.1 L/h | |
| Nominal vibration amplitude† | ±15 nm |
| Positional drift‡ | ±10 nm in 5 min |
| ±60 nm in 30 min |
NOTE: Specifications do not include optical or experimental heat loads and assume horizontal orientation. Specifications may change depending on the length of the transfer line flexible section.
†Vibrational amplitude measured while on an isolated optical table. Results may vary depending on experimental conditions.
‡Data courtesy of B. B. Goldberg and M. S. Unlu, Departments of Physics, ECE and Photonics Centre, Boston University.
Vibration measurements
Long-term drift data
ST-500 long term drift data from University of Oxford, Janis Research, cryogenics
Data taken by K.H. Lee (University of Oxford)
The Taylor group at the University of Oxford has performed some characterisation of the ST-500 cryostat drift. The characterisation is based on the tracking of a single QD over time, and test results indicate a typical positional drift of about 2 nm/min.
Other configurations
Compact and ultra-compact configurations
Compact and ultra-compact designs are also available if space restrictions do not allow the use of the ST-500. See details for the ST-300-MS SuperTran cryostat and the ST-500-UC ultra-compact cryostat.
Special ST-500-LGV with 11 in diameter vacuum shroud
The customer-designed sample holder was very large so a large 11 in diameter vacuum shroud was used.
Sample extension for magnetic measurements
Using the same proven cryostat design as the regular ST-500 cryostat, the ST-500 for magnetic measurements features an extended sample mount for use inside the bore of a magnet. This extended sample mount may be purchased separately or with a set of permanent magnets for measurements in fields of up to 0.5 T.
These photos show the ST-500 with an extended sample mount and permanent magnet. The length of the extension may be specified at the time of order, and the position of the magnet relative to the sample is fixed using a Teflon spacer. The magnetic field direction is perpendicular to the plane of the sample.
The flexible ST-500 design means that the cryostat may be ordered with an extended sample holder and vacuum shroud for magnetic measurements, and a standard sample holder and vacuum shroud for other measurements. Switching between the two holders is as simple as changing samples.
A set consists of up to five interchangeable magnets: the full set allows measurements in discrete steps of 0.1 T. Existing ST-500 cryostats may be upgraded by simply ordering the special sample holder, vacuum shroud top plate, and radiation shield cover.
Superconducting magnet for high-resolution microscopy
Designed to operate with a Janis high stability microscopy cryostat, this system allows microscopy measurements to be performed in fields of up to 6 T. The system comes with x-y-z translation stages for sample scanning and focusing, and is designed for magneto-optical imaging at helium temperatures.
O-ring sealed top and bottom windows
For customers who require soft windows that cannot be epoxy sealed, we offer the option of using an o-ring seal to install the windows. The lower window is recessed so that it is flush with the bottom surface of the cryostat. The photo shows a cryostat with an o-ring sealed top and bottom windows. This cryostat also featured a breakout box.
Mounting flange for optical table
This ST-500 includes a mounting flange to allow it to be bolted to an optical table.
