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SVT-400 High-efficiency Cryostat

Janis

Designed for maximum efficiency at any temperature range, the SVT-400 will hold liquid helium for more than 40 hours during sample zone use (or more than 100 hours if the sample zone is static). The sample tube is surrounded by a nitrogen-temperature radiation shield; therefore operation at elevated temperatures does not place any additional heat load on the helium reservoir.

Standard Configuration

The Janis Model SVT-400 variable temperature cryostat is designed to run efficiently with either liquid helium or liquid nitrogen. The system's ultra-low cryogen consumption, remarkable temperature homogeneity and stability make it ideal for long or short term experiments. The top loading sample positioner features quick sample exchange and is offered with a variety of sample holders.

The standard cryostat is supplied with strain-relief mounted, replaceable quartz windows. Various choices of window materials are available to cover most regions of the electromagnetic spectrum, including Gamma rays, UV, visible and IR radiation. Typical applications include transmission, reflection and Raman spectroscopy, neutron diffraction, Mössbauer spectroscopy, other magneto-optical and electro-optical experiments.

Tubular tailed systems are offered for electrical and magnetic measurements, compact VSM, Hall effect and NMR experiments. Both high temperature and low temperature experiments are economically performed using the most desirable cryogen.

Complete "turn key" systems are supplied with various choices of thermometry, for use both in and out of magnetic fields and at high temperature ranges.

Standard Features

• Indium sealed, strain relief cold windows
• Radiation shield cold windows
• 50/25-ohm heaters on vaporizer heat exchanger/sample mount
• Helium valve
• Instrumentation feedthrough on cryostat body
• 8-pin & 10-pin electrical feedthroughs on sample positioner
• Optical or blank sample holders
• Standard silicon diode control thermometers
• Isothermal zone sample tube (provides uniform sample temperature and enhanced operation with LN2)

Options

• LHe and LN2 level indicator
• Multipin and coaxial electrical connectors
• Additional temperature sensors and controllers
• Alternative window materials
• 10-pin electrical feedthrough on cryostat body
• Universal joints for sample positioners
• Custom sample holders
• Bottom looking optical access

Specifications

LHe reservoir capacity	6 Liters
LN₂ reservoir capacity	5 liters
LHe hold times:
Static sample zone	90 hours
Sample zone use (<10 K)	36 hours
LN₂ hold time	36 hours
Temperature range:
LHe	1.5 - 300 K
LN₂*	65 - 300 K
Temperature stability	± 0.1 K
Outer tail dimensions:
Optical (including retainers)	4.38"
Non-optical	3.00"
Weight:
Optical	66 lbs.
Non-optical	55 lbs.
Optical windows	4 radial
Solid angle	38°
f number	1.4
* Optional high temperature to 600 K is available on non-optical systems.

Other Configurations

Model SVT-400 for Mössbauer Spectroscopy *

*Other window configurations available.

Model SVT-400 with Sample in Vacuum

The Model SVT-400 with sample in vacuum replaces the Model VT-100 cryostat. Instead of having a sample positioner with a sample holder cooled by flowing vapor, as the standard Model SVT-400 cryostat does, this special Model SVT-400 cryostat has an optical sample holder mounted to the bottom of the sample tube. This allows the gas in the sample tube to cool the sample holder while the sample is held in a vacuum.