BUCKET DEWARS
(Open Neck, Wide Mouth Dewars)

Characteristics: Large direct opening to liquid helium.
Construction: Choice or stainless steel or aluminum fiberglass.
Typical Use:

Superconducting magnets and other large inserts are
introduced into liquid helium from the top. Inserts are
usually supported and sealed by the dewar's top flange.

Style: a. Liquid Nitrogen Shielded - a separate reservoir of liquid
nitrogen surrounds and shields the liquid helium.
Style: b. Vapor Shielded - the liquid helium vapor exiting the dewar
cools multiple shields located in the vacuum space.


Bucket DewarBucket Dewar

Stainless Steel Dewars
All welded construction, very rugged and highly polished for great looks.

Aluminum Fiberglass Dewar

Aluminum Fiberglass Dewars
Vapor shielded aluminum fiberglass is the most popular style for bucket dewars. This style dewar fills fastest and requires no liquid nitrogen maintenance. 'Belly' options are available to increase the liquid helium volume. The epoxy fiberglass necks have helium gas diffusion barriers. The highest efficiency is obtained by a combination of 'hard' shields and multiple 'soft' (foil) shields, located in the insulating vacuum space.