4 K Cryocoolers — Sample in Vacuum Systems (SHI-4 Series)
Janis SHI-4 series cryostats are among the most versatile systems available for laboratory sample cooling. They are equipped with interchangeable optics and include provisions for a wide variety of electrical connectors. Tapped holes on the vacuum shroud and a sturdy mounting flange provide for convenient mounting in any orientation.
These cryostats are designed for measurements to 325 K, and optional configurations permit operation to 500 K or 800 K (with special thermometry).
Optimized for experiments requiring optical access to the sample, these systems include the following components:
- Optical vacuum shroud and radiation shield
- Four o-ring sealed quartz windows
- Gold-plated OFHC copper sample holder
- 10-pin electrical feedthrough, with three spare electrical access ports
- Evacuation valve and safety pressure relief valve
- Silicon diode thermometer and control heater
- Easily removable window block with an o-ring seal located just above the windows (SHI-4-2 and SHI-4-5 systems only)
- Additional electrical feedthroughs (BNC, SMA, multipin, and others)
- Rotatable vacuum shroud
- Rotation and positioning stages
- Matrix isolation configuration
- Fifth window port
- Radiation shield windows
- Specially modified window block with a larger window as an option (SHI-4-x)
- IR and other window materials
- Custom designed vacuum shroud
- 500 K & 800 K high-temperature systems available on most models (800 K with special thermometry)
- Non-optical configurations
- Compact vacuum shroud (for use with electromagnets)
- Large sample volume configurations
Standard models include:
("X" indicates the cooling power of the refrigerator)
- SHI-4-X (optical)
- SHI-4T-X (non-optical)
- SHI-4S-X (sub-compact)
- SHI-4XG-X (low-vibration interface)
- CCR4-MMP (cryogen-free probe station)
(including radiational heat load)
|Temperature Range||<4 K* to 300 K||<4.5 K to 325 K||<4 K to 325 K||<4 K to 325 K|
|Initial Cooldown Time||<120 min to 5 K at 60 Hz|
<150 min to 5 K at 50 Hz
|~70 min to 4.5 K||60 min to 4 K||60 min to 4 K|
|0.13 W at 4.2 K|
0.2 W at 4.2 K
|0.7 W at 4.2 K||1 W at 4.2 K||1.5 W at 4.2 K|
|Cryostat Weight||36 lb||53 lb||62 lb||63 lb|
|Compressor Cooling||Air or Water||Water||Air or Water||Air or Water|
|* With four open radiation shield ports, f1 view angle.|
NOTE: 500 K and 800 K versions available on most models.
Special designs include:
- Pulse tube-based systems
- Specialized for neutron scattering and diffraction applications
4 K closed cycle refrigerator with 2-axis optical alignment
Janis Research Company is proud to announce rotation and positioning stages for our 4 K closed cycle sample in vacuum cryostat systems. Rotation about the cryostat access has ~0.5° resolution and a range of ±360° about the cryostat axis and rotation is only limited by the helium flexlines and electrical cables. Rotation off the cryostat access has a resolution of <0.2° and a full range of 0° to 90° of motion. The system comes with four radiation shield windows and reaches a sample base temperature of ~4 K. This system is ideal when fine optical alignment is required for experimental samples. Download a mechanical drawing of this system. (PDF 101 KB).
This photo shows a bare model RDK-415D2B cold head with a non-rotatable 8 in CF flange and a heater block on the 2nd stage with a temperature sensor and two cartridge heaters. The system is designed to mount directly onto a user-supplied UHV chamber. This is not a "true UHV" system because the baking temperature is limited to 60 °C; it is designed for high vacuum conditions.
This special SHI-4XG-15-UHV is a true ultra-high vacuum (UHV) system that can be baked out to 500 K with exchange gas vibration isolation. This particular customer plans to use this system in scanning probe microscopy measurements. With this special system's radiation shield window configuration, it has a base temperature of 3 K.
Special 1.5 W system for cooling hydrogen gas
Special Model SHI-4-15 with a conflat flange and heat exchangers on the 1st and 2nd stages for cooling hydrogen gas. The end user will install this cryocooler in an existing vacuum chamber and make his own connections to his Hydrogen inlet and outlet lines.
Special 1.5 W at 4.2 K system with coils wrapped around the 1st and 2nd stages for cooling gas from room temperature to ~4 K
This special model SHI-4-15-UHV was used in ion trap measurements. Janis Research provided the cold head with the cooling coils and an instrumentation skirt. The second stage has a heater and temperature sensor to make it a fully variable temperature system. The customer connected the cooling coils to their room-temperature gas supply with the other end going into the ion trap.
Similar systems could be used in other applications to condense any gas into liquid.
Standard window block with countersunk screw holes option
Janis Research usually uses pan-head screws on the retainers of window blocks, which add about 0.125 in to each side of the window block. In cases were space is an issue, talk to your sales engineer about countersunk screw holes in the retainers so that flathead screws can be used, as shown in this photo. This option can be offered on most window blocks with o-ring sealed windows. The window block shown can be used on our model VPF-100, VPF-800, ST-100, CCS-150, CCS-100/202, CCS-100/204, and SHI-4-2.
Modified window block
The photos show a standard optical cryostat with a specially modified window block. Two of the windows are our standard 1.63 in diameter clear view fused quartz. The other two windows are a special 2.63 in diameter clear view fused quartz. This window block can be used as an option on many other systems such as ST-100, VPF-100, SHI-4-2, SHI-4-5, SHI-4, CCS-150, CCS-450, CCS-100/202, and CCS-100/204. (The CCS-100/204 uses an optional large window using a different window block.)
Optional rotating stand for 4 K and 10 K cryocooler systems
This model PTSHI-4-5 features an optional rotating stand that allows the user to flip the entire cryostat upside-down. This is convenient for changing samples. The cryostat itself is rather heavy and it doesn't have any flat surface that will allow it to rest upside-down by itself. Without this rotating stand, gaining access to the sample area would be very difficult and inconvenient. This particular stand is designed to hold the cryostat 50 mm above the surface of an optical table but could be designed to hold the cryostat at any height specified by the customer. This stand can be used for 4 K and 10 K cryocooler systems.