HE-3-BLSUHV-STM Helium-3 Cryostat


"Wet" System - Bottom-loading into UHV - for Scanning Tunneling Microscopy

The model HE-3-BLSUHV-STM is a bottom loading vibration isolated He-3 system for Scanning Tunneling Microscope (STM) application with sample in UHV environment.

A UHV sample preparation chamber can be installed at the bottom of the cryostat; and the user is able to lower the He-3 insert with a linear motion manipulator and locate the STM inside the UHV chamber for sample change.

A special "helium-only" dewar with double helium vapor cooled radiation shields was developed for this system in order to minimize the vibration. No liquid nitrogen reservoir is employed in this cryostat.

An "isolation" helium reservoir separates the UHV sample space from the dewar vacuum space. It minimizes the UHV space and makes the UHV pumping easier.

A self-contained UHV compatible He-3 insert is included in this system, and multiple measurements are taken to guarantee the alignment of this insert during its sample change and normal operation.

A high field superconducting magnet is included.

This He-3 cryostat includes the following components:

  • Vapor cooled helium-only dewar
  • Helium isolation reservoir
  • Multiple liquid helium level probe
  • Digital cryogen level monitor
  • UHV compatible linear motion manipulator
  • UHV compatible feedthrough manifold
  • UHV compatible aligner
  • Self-contained He-3 insert, including
  • Charcoal sorption pump with heater and thermometer
  • 1 K pot with thermometer
  • He-3 pot with heater and thermometer
  • Permanently stored He-3 gas
  • Superconducting magnet
  • Shutters
  • Operation test


  • UHV compatible resistive wires
  • UHV compatible coaxial cables
  • Fiber optics
  • Computer controller motorized 1 K pot cryogenic needle valve
  • Automatic temperature controller
  • Liquid helium transfer line
  • Magnet power supply
  • 1 K pot pumping station
  • Turbo pumping station
  • UHV compatible coaxial cables

Performance Specification

Base temperature: 300 mK
Hold time at base temperature: 60 hours
Operation temperature range: 0.3 - 300 K
Sample space: 1.5"


Two Axis Superconducting Magnet


HE-3-BLSUHV-STM helium-3 cryostat, Janis Research, ultra low temperature, ultra high vacuum, scanning tunneling microscopy
Model HE-3-BLSUHV-STM Helium-3 Cryostat
Shutters on model HE-3-BLSUHV-STM helium-3 cryostat, ref. 9009, Janis Research, ultra low temperature, ultra high vacuum, scanning tunneling microscopy
Cooled Shutters on Model HE-3-BLSUHV-STM Helium-3 Cryostat