Liquid Nitrogen Dewar / Cold Trap

A double-walled, vacuum isolated dewar with DN40CF flange including a DN16CF side port for an electrical feedthrough. The cold plate features four M3 holes in an 18mm square for mounting in-vacuum equipment.

• LN₂ filling volume: ~0.5lt (~0.4lt with foam cap)
  
• Dewar vacuum isolated
• Foam cap included
• Mounting flange: DN40CF (2.75")
• Feedthrough flange: DN16CF (1.33")
• Fully UHV compatible materials
• The side port is blanked off (= electrical feedthrough is not included)
  
• incl. thermal insulating sleeve and cover

+ With included (pre-assembled) heat exchanger, heating coil and temperature sensor the LN₂ cold trap can be used as a cryopump. This so called "UHV booster" for small transfer chambers (e.g. in combination with the fast pump down dock), "boosts" pumpdown. Used in combination with a turbomolecular pump, it reduces base pressure about a factor of 10 in a given time and thus enables exceptionally fast sample transfer from a portable UHV suitcase into the UHV system.
After filling the dewar with liquid nitrogen, the heat exchanger on the vacuum side of the cold trap is cooled down within a couple of minutes and thus a sufficient vacuum level for transferring clean samples is established within approx. 30 minutes.

By using the cold trap is to establish UHV, bakeout is not required. This has the additional benefit of the UHV Suitcase not heating up along with the transfer chamber, which would negatively influence the vacuum inside the UHV suitcase.

For quick warm-up, the cold trap can be heated via a built in resistive heater. A filling of 0.5lt will keep the dewar cold for approximately 3h.

Temperature during cooldown and warmup is monitored using an integrated PT100 sensor. A 3m cable with a suitable connector for the cold trap heater is included.

• heat exchanger: Aluminium cooling blocks with OFHC core
• pumpdown time (with VSCT40): approx. 30 minutes to a pressure of around 1E-8 mbar
• cooling temperature cryo trap: 80K
• built-in resistive heater for quick warm up
• Pt100 temperature sensor
• 6-pin miniature feedthrough
• cable 3m with a suitable connector is included