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PP2000/PP2000T Preparation Chamber



The preparation chamber is attached to the microscope and provides preparation facilities needed for all types of samples. The chamber is a totally enclosed vacuum environment with integral gate valves to ensure stable contamination free operation. A variable temperature cold stage is mounted centrally in the chamber. Cooling is by a copper conduction bar in direct contact with a liquid nitrogen cooled stainless steel vacuum dewar. The specimen stage can be cooled to below -180^oC and heated to 50^oC and controlled within an accuracy of + or - 1^oC


Preparation chamber cold stage (view through loading port)	Preparation chamber cold stage (view through front viewing window) Note that the manipulation tools (knife and cooled probe) are located on the top of the preparation chamber, leaving the large front facing observation window totally clear.

The preparation chamber has many standard built-in features not found in other systems, or only available as options: Two specimen fracturing devices A robust cooled probe can be used to burst specimens open, or a micrometer controlled steel knife can be used to cleave samples.


Preparation chamber cold stage and knife (above) - viewed though loading valve.	Cooled probe (in front of cold stage) and knife (centre left). Also note cold traps above and below sample stage. Further to the rear the large internal surface of the cooling dewar (at -196^oC) is an extremely efficient cold trap.

Large and effective internal cold trapping The PP2000 is designed with the cooling dewar built in to the preparation chamber. This gives a large "trapping" surface for water vapour and contaminants. In addition, further cold traps are located above and below the sample stage; the lower cold trap is sufficiently large to capture fracture fragments that may otherwise warm up and introduce contamination. Sputter coating A compact low energy sputter coater is fitted enabling high-resolution coating of gold / palladium (standard), platinum or other metals. The sputtering head has been specifically designed to meet the special requirements of cryo-preparation. Argon gas used in the sputtering process can be provided by a small cylinder of ultra-high purity (PP2000T). For non-high resolution applications standard grade argon from a cylinder can be used.

Standard "cool" sputtering head (left) and optional carbon head	Sputtering. Note: high-purity argon canister (PP2000T only)

Film Thickness Monitor (FTM) The optional PP7690 can be used to precisely control the thickness of sputtered films. The crystal is located very close to the sample stage.


FTM crystal and crystal holder (holder rotated towards viewing window for clarity)	PP7424 Stereo microscope

Large viewing window The large size and position of the window gives the user a very clear view of the sample. This is particularly useful during fracturing when the sample can be viewed along the fracture line. Note that for internal access (e.g. for cleaning) the front panel can be easily removed (four hexagonal nuts) For an even better view an optional stereo microscope (PP7424) with 10x / 20x magnification can easily be fitted. When not required for cryo applications, the PP7424 can be easily removed and remounted on its own bench stand. Internal illumination Chamber illumination, essential for sample preparation, is fitted inside the chamber leaving the viewing window clear for sample observation. Airlock pumping and venting controls located on the preparation chamber Having the controls so close to the loading gate valve means sample transfer is easier and faster.	Note: controls for sample transfer (to the right of cooling dewar) located conveniently close to preparation chamber airlock