Coolstage - Peltier-Cooled SEM Stage

The Coolstage is a Peltier-driven cooling stage for scanning electron microscopy (SEM), low vacuum (LV) or variable pressure (VP) applications. Three models are available to cover differing user requirements.

Key features

• Temperature range -30°C to +50°C at 300 Pa
• Self contained cooling - no additional external cooling water needed
• Temperature accuracy +/- 1.5°C or 2% - whichever is greater
• Minimal image drift
• Cooling and heating rates of up to 30°C per minute
• Keypad control - with simultaneous display of actual and target   temperature
• Supplied with SEM chamber port feed-though - specify when ordering

Product description

The Coolstage is a Peltier-driven SEM cooling stage for scanning electron microscopy (SEM), low vacuum (LV) or variable pressure (VP) applications. The stage can be cooled to sub-zero temperatures for specimens that may be sensitive at ambient temperature, subject to beam damage, or may otherwise ‘sublime’ (lose water) at ambient temperatures.

Three products

There are three versions of Coolstage: Standard, Enhanced and Ultra, designed to cover differing specimen requirements.

The Standard Coolstage consists of a single stage Peltier device, onto which a thermally isolated specimen holder and dual temperature sensor is mounted. The Coolstage assembly is mounted onto the SEM stage using an adaptor plate specific to the microscope. Cooling pipes and electrical wires connect to the SEM feedthrough flange. External components are a recirculating water chiller power supply case and a compact keypad for digital temperature readout and control.

Alternative products in the Quorum range:

• For lower temperatures than Peltier cooling can give? The PP3005   SEMCool offers close-to liquid nitrogen temperatures (down to -190°C)
• For liquid nitrogen temperature cooling with a specimen load-lock?   Please see: PP3006 CoolLok
• For a full low temperature cryo preparation system for SEM and FIB/SEM    (including rapid freezing, vacuum transfer, cold fracturing, sublimation   and sputtering) please see: PP3010T.

Compact, efficient cooling and temperature control

The temperature range of the Standard Coolstage is -30°C to +50°C at 300 Pa. The specimen holder is water-cooled using a small, self-contained closed loop recirculating chiller that is normally positioned approx 2m from the SEM. A microprocessor controls and monitors the temperature of the cold stage. A small keypad is used to set the required temperature and display target and current temperatures.

The specimen holder has been designed to minimise image drift due to temperature change, giving a stable image at high magnification. An integrated RS-232 interface allows temperature to be set and read from the SEM.

Rapid specimen exchange

To exchange a specimen it is necessary to increase the specimen stage temperature to ensure that condensation does not form on the specimen or specimen stage. The keypad controller has a convenient ‘exchange’ button that will automatically take the specimen holder temperature to a programmable temperature from between +5ºC to +20ºC. Typical cooling and heating rates are up to 30ºC per minute.

When not in use, the major parts of the system can be left in situ and the cooling stage is very easily removed when reverting to ‘normal’ use. A convenient storage block is provided for Coolstage stage assembly and vacuum feedthrough for when the system is not in use.