VNF Series Cryostat Systems—Sample in Flowing Vapor

Ideal for samples with poor thermal conductivity, the VNF cryostat provides uniform cooling for irregularly shaped samples. Samples are cooled by a temperature-controlled stream of nitrogen vapor, so the cooling is not dependent on the sample mounting configuration or thermal conductivity. (A specialized model is shown to the right.)

Standard configuration

VNF-100 mechanical drawing

The Janis VNF-100 cryostat is a liquid nitrogen variable temperature cryostat with the sample located in flowing vapor. Ideal for experiments with samples that are difficult to thermally anchor such as liquid or powder samples, the VNF-100 is a low-cost alternative to the SuperTran-VP or SuperVariTemp Dewars when temperatures below 65 K are not required. The VNF-100 features a top-loading sample chamber for rapid sample exchange, and four-way, f = 1.0, optical access to the sample chamber.

Standard features:

  • Quick refill capability with included funnel assembly
  • High-quality bellows-sealed evacuation valve and a built-in cryopump for maintaining high vacuum
  • Safety pressure relief valves protecting all independent spaces
  • 1.25 in diameter sample tube with customer-specified optical access (standard system offers four quartz window pairs with f = 1.0 optical access to the sample space)
  • Top-loading sample chamber for rapid sample exchange
  • Variable cooling system that places the sample in flowing N2 vapor (ideal for low thermal conduction samples), providing excellent cooling power and temperature control
  • Lightweight sample positioner/mount assembly, with multi-pin electrical feedthrough access to the window region, offering rotation and translation around the cryostat axis
  • Two silicon diodes installed on the vaporizer (heat exchanger) and sample mount for controlling and monitoring the system temperature

Optional equipment:

  • Exhaust flow gauge for more precise control
  • Special window materials and geometries (IR, UV, and x-ray)
  • Special sample holders including four-point resistivity measurement and liquid cuvettes (see other configurations)
Janis — a Lake Shore Company
VNF-100 Liquid Nitrogen Cryostat

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VNF Series Specifications

LN2 capacity (nominal)1.2 L
Working time (typical)Approximately 6 to 8 h
Initial cooldown time (from room temperature)Approximately 30 min
Sample exchange time (typical)Less than 5 min
Operating temperature range65 to 325 K
Temperature stability (with temperature controller)50 mK or better
System weight19.0 lb (11.5 kg)

 

Other configurations

Special Model VNF-100 with base-plate to mount to a HORIBA Jobin Yvon FluoroLog-3 modular spectrofluorometer

VNF-100 optical LN2-cooled cryostat

Model VNF-100T

VNF-100T non-optical LN2 cryostat

Special 475 K high-temperature non-optical VNF-100T

VNF-100HT special 475 K high temperature non-optical cryostat

VNF-100T with black anodized mounting flange around the body

VNF-100T

Optical VNF-100 cuvette sample holder

This photo shows a cuvette sample holder for installation on an optical VNF-100. It is compatible with all 12.5 mm wide × 12.5 mm deep cuvettes such as the Starna models 1-G-10, 1.7-G-10, 1-SOG-10, 1-Q-10, and 1-I-10. VNF-100 cuvette sample holder