DMX - 20B Interface

DMX - 20B Description

The DMX-20B is a low vibration interface for the Displex Refrigerator. One side of the interface attaches to the DE-202 flat flange refrigerator, which is then bolted to a separate rigid framework. The other side of the interface is designed to bolt cold-end-down into a vacuum chamber using a conflat flange. Helium exchange gas is used to transfer heat from the sample mount on the interface to the DE-202 cold end (see Principle of Operation) and a bellows assembly decouples the two sides of the interface isolating DE-202 cryocooler vibration from the vacuum chamber. The DMX-20B comes complete with DMX-20B interface assembly, bellows assembly, and radiation shield.

Features

Patented exchange gas design provides vibration isolation.
Suitable for many vibration sensitive applications
UHV compatible
Successful installations worldwide
Closed Cycle Operation from 12K to 350K
DMX-20 Low Vibration Mossbauer / Optical Shroud availalble

Principle of Operation

Patented exchange gas design operates as follows: Helium gas is introduced into the exchange gas cavity through a valve supplied with the DE-202-side of the interface. The DE-202 cryocooler is switched on and begins cooling. Natural convection loops form around both the first and second stages of the cooler. The convection loop at the first stage cools the radiation shield and the convection loop at the second stage cools the sample. Helium next to the DE-202 cryogenic refrigerator is cooled and becomes more dense and thus moves down inside the gas cavity. As this relatively colder helium flows past the DMX-20B interface, heat is transferred from the interface to the Helium. As heat is transferred into the gas, it begins to warm and rise up the inner wall of the interface. It is then pulled back into close proximity to the DE-202 by helium which has already cooled and moved down the cavity. Separate heat exchangers mounted on the DE-202 second stage and inside the DMX-20B cold tip enhance heat transfer to provide minimum temperature at the sample mount.