LT3M Helium Flow Cryostat


The ARS manufactured LT3M is an extended length true UHV cold head (10-11 Torr) where all of the rubber o-ring seals have been replaced with welded joints and metal seals.

The LT3M is ideal for UHV surface science where very long cold fingers are required. The LT3M has a customizable length up to 1200 mm and a rigid support tube to allow for cleaving and manipulation. The upturned feedthroughs limit the rotational footprint to just 4.8 in.

Like all of our LT3 liquid helium flow cryostats, the LT3M is an advanced liquid helium flow cryostat utilizing many unique features, such as the Matrix heat exchanger and the co-axial shield flow transfer line, to achieve unparalleled efficiency and vibration levels.



  • UHV - XYZ manipulation and rotation
  • Surface science
  • Molecular beam epitaxy (MBE)
  • Photo emission spectroscopy (PES)
  • Photoemission electron microscope (PEEM)



Typical Configuration


Options & Upgrades

  • 1200 mm customizable length
  • 4.8" rotational footprint
  • True UHV (10-11 Torr)
  • Bakeable
  • Open sample space
  • Optional cold tip extensions
  • Liquid helium flow
  • Matrix heat exchanger
  • Co-axial shield flow
  • Precision flow control
  • Exhaust heater
  • Operation in any orientation
  • Fully customizable


  • Cold head (LT3M)
  • Co-axial shield flow liquid helium transfer line
  • True UHV welded stainless steel instrumentation skirt with 4.5 in. rotatable CF flange
  • Stainless steel support tube
  • Dewar adapter
  • Flow meter panel for helium flow control and optimization
  • Nickel plated OFHC copper radiation shield terminating 0.125" short of the cold tip
  • Instrumentation for temperature measurement and control:
    • 10 pin UHV feedthrough
    • 36 ohm thermofoil heater
    • Silicon diode sensor curve matched to (± 0.5 K) for control
    • Calibrated silicon diode sensor (±12 mK) with 4 inch free length for accurate sample measurement
  • Wiring for electrical experiments:
    • 10 pin feedthrough
    • 4 copper wires
  • Sample holder for optical and electrical experiments
  • Temperature controller