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SuperVariTemp Cryostat Systems - Sample in Flowing Vapor
Janis
The Janis Research SuperVariTemp (SVT) system is the basis for a variety of variable temperature cryostats. Offering quick sample exchange, an operational range of 1.5-300 K and highly efficient operation, this versatile system is often incorporated into Janis' CNDT series dewars or, for maximum flexibility, this concept is applicable with virtually any dewar.By controlling the temperature of the flowing helium vapor in which samples are immersed, both the sample and holder are simultaneously cooled to the same temperature, thereby eliminating the need for thermal anchoring and sample mount heating. The helium flow rate and heater current are balanced to provide flowing vapor/sample temperatures over the range of 1.5-300 K; automatic temperature controllers together with application specific thermometry provide accurate and precise temperature control.
The SVT cryostat makes full use of the cooling power of escaping helium vapor as it exits the sample chamber, resulting in improved efficiency over exchange gas systems. Operation of the SVT typically adds about 0.1 L/hr to the total liquid helium evaporation rate of the dewar. The sample chamber is thermally isolated from the helium reservoir by the dewar vacuum, thereby eliminating heat conduction into the reservoir. This provides for low helium consumption rate even at higher sample temperatures.
The SVT's unique design allows for operation below 4.2 K without wasteful pumping on the main helium reservoir. Operation below lamda is readily achieved with the sample immersed, either in liquid or vapor, by simply throttling the rate of helium introduced to the sample chamber while evacuating the sample tube.
All SVT Models Include:
• Janis Research SuperVariTemp system
• Top-loading sample positioner
• One (1) 10-pin and two (2) 8-pin electrical feedthroughs
• Safety pressure relief valve
• System test
Options include
• Isothermal zone sample tube (provides uniform sample temperature and enhanced operation with LN2)• Bottom looking optical access
• Indium sealed, strain-relieved, cold windows
• Cooled radiation shield windows
• Liquid helium level indicator
• Liquid nitrogen autofill system
• Multi-pin and coaxial electrical connectors
• Alternative window materials
SVT-200 Optical Systems
Optical cryostat for experiments requiring long hold times or a larger sample space, featuring a 6 liter liquid helium capacity.
SVT-200T Tubular Systems
Non-optical cryostat for experiments requiring long hold times or a larger sample space, featuring a 6 liter liquid helium capacity.
SVT-200T-NMR Tubular Systems
Similar to the standard SVT-200T, but custom designed for NMR Spectroscopy.
SVT-300 Optical Systems
Designed with long-running experiments in mind, this optical cryostat features an increased liquid helium efficiency and a 5 liter helium capacity.
SVT-300T Tubular Systems
This cryostat incorporates an increased liquid helium efficiency in a tubular tail design for long-running non-optical experiments.
SVT-400 High Efficiency Variable Temperature Cryostat
The system's ultra-low cryogen consumption, remarkable temperature homogeneity and stability make it ideal for long or short term experiments.
Double Rotating Sample Positioner
Janis offers special sample positioners with the ability to rotate the sample about the optical axis of the cryostat.
Options & Accessories
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SuperVariTemp |
VariTemp |
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(sample in flowing vapor) |
(sample in exchange gas) |
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1.25" diameter optical sample holder with retainer |
A9-OSH-ST |
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1.25" diameter resistivity sample holder with eight (8) pins |
A9-RSH-ST |
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1.25" diameter blank sample holder with four (4) tapped holes |
A9-BSH-ST |
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Other size sample holders |
Consult QD-Latam |
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Stainless steel storage dewar (36 liter capacity) |
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Stainless steel storage dewar (70 liter capacity) |
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Stainless steel storage dewar (110 liter capacity) |
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A8-FHT |
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8-pin electrical feedthrough with mating connector, flange-mounted |
A9-8P-ASSY |
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10-pin electrical feedthrough with mating connector, flange-mounted |
A9-10P-ASSY |
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19-pin electrical feedthrough with mating connector, flange-mounted |
A9-19P-ASSY |
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BNC electrical feedthrough (single), flange-mounted |
A9-BNC-1 |
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BNC electrical feedthrough (double), flange-mounted |
A9-BNC-2 |
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Double miniature coaxial feedthrough (SMA), flange-mounted |
A9-SMA-2 |
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Thermocouple feedthrough, flange-mounted |
A9-TC-1 |
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Triax electrical feedthrough, flange-mounted |
A9-TRIAX |
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Window blanks (set of 2) |
Consult QD-Latam |
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Special order optical windows |
Consult QD-Latam |
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Consult QD-Latam |
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Bottom-looking optical access |
Consult QD-Latam |
Not Available |
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Indium sealed, strain relief mounted cold windows |
Consult QD-Latam |
Not Available |
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Cooled radiation shield windows |
Consult QD-Latam |
Not Available |
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Liquid helium level sensor and display |
Consult QD-Latam |
Not Available |
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Liquid nitrogen autofill system |
Consult QD-Latam |
Not Available |
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Spare sample positioner assembly |
Consult QD-Latam |
Not Available |
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Helium gas collection adaptors |
Consult QD-Latam |
Not Available |
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Isothermal sample zone |
Consult QD-Latam |
Not Available |
