With increased use of Low Vacuum or Variable Pressure microscopes, many microscopists now appreciate the need to control water sublimation from wet samples. By cooling a wet specimen, water sublimation may be slowed or depending on chamber pressure stopped altogether. Saturated vapour pressure of water decreases considerably with temperature.
At room temperature water will very quickly sublimate causing considerable changes to the specimen structure. At 300 Pa, specimen temperature needs to be less than -9.5°C and at 85 Pa specimen temperature needs to be less than -25°C to stop sublimation. Therefore by cooling a specimen to -25°C, chamber pressure may be 85 Pa with limited sublimation from the specimen. Advantages of this procedure are clear to see, by cooling a specimen in low vacuum, changes in specimen structure due to sublimation can be minimised and the ability to operate at higher vacuum provides a better signal to noise ratio and clearer images. With Environmental SEMs where imaging is possible in a gaseous environment temperature and vacuum can be perfectly matched to keep the specimen fully hydrated during imaging.
The Deben stages can also be used for high vacuum heating and cooling applications inside the SEM.
Standard SEM Coolstage -25°C to +50°C
The Deben Coolstage is available for all SEMs and guaranteed temperature range is +50°C to -25°C (at 300Pa chamber pressure) or less than -30°C at higher vacuums.
Enhanced Coolstage -25°C to +160°C
The Enhanced Coolstage provides the same features as the standard Coolstage but with an extended temperature range of +160°C to -25°C (at 300Pa chamber pressure) or less than -30°C at high vacuum.
ULTRA Coolstage -50°C to +50°C
The Ultra Coolstage provides the same features as the standard Coolstage but with an extended temperature range of +50°C to -45°C (at 300Pa chamber pressure) or less than -50°C at high vacuum.
SPRITE stage automation systems are available for most electron microscopes.
Systems comprise joystick controller, microprocessor controlled electronics and from two to five SPRITE motor drive units.
The key to SPRITE system performance is our micro-stepping drive unit, specially designed for driving electron microscope stages. Resolution is 50,000 steps per revolution, giving smooth movement at stage speeds from 10nm per second to 2.5mm per second.
You can use the SPRITE motor drive at magnifications from x10 to x100,000 and beyond. Most SPRITE drive units have handwheels so the user can move the stage manually if needed. Optical encoders ensure that you never lose position and integral limit switches mean that installation is normally quick and simple.
SPRITE motorisation not only gives you easy movement of all stage axes, but also the ability to store and recall co-ordinates, set up scan patterns, sequence moves and montages. An RS-232 interface enables stage movement to be controlled from any computer, allowing your stage to be driven by all leading EDX systems.
Motorising your SEM or TEM stage brings benefits in all electron microscopy applications, saving time, increasing productivity and reducing operator fatigue. Any electron microscope can be upgraded with SPRITE stage automation.
Computer control of the microscope stage is easy using the built-in RS-232 interface. Simple commands allow the user to incorporate stage control into any application program. Data transfer speed is normally 9600 baud, but different rates can be selected. Deben can supply sample source code for those programmers developing their own software.
X-ray analysis (EDX or WDX) can be fully automated using SPRITE automation. We have RS-232 software protocols for mostmanufacturers systems, enabling analysis of a wide range of samples to be performed totally unattended. The operator examines the sample as normal to locate points of interest, these are then stored as a point file in the EDX (or WDX) system, to be recalled as part of the analysis program. Often the EDX system allows more complex stage manipulation as part of the system software, for example, defining regions of interest, scan patterns, etc.
Image analysis and archiving can also be automated using the SPRITE stage control system. While the montage capability allows some automation in image recording, many image analysis programs have facilities for stage control, and can be set to first store the images from a number of areas of the sample, then to perform a wide range of counting, sizing and measurement functions automatically.
The ballistic comparison stage is designed to accept the most common bullets and cartridge cases and allows two samples to be mounted side by side for detailed comparison. Each sample can be independently rotated through 360 degrees and their relative heights adjusted.
- Substage for use with dual objective optical microscopes or SEM
- All in-situ components are designed for use in vacuum and are non contaminating
- Stage mounts onto SEM stage using dovetail fittings to match SEM
- Electrical connections are via an X-ray safe vacuum feed-through
- Accommodates bullets from 10mm to 90mm long
- Accommodates cartridge cases form 4.5mm to 19mm diameter
- Location on top of stage for pin stub GSR reference specimen
- Speed ranges: 1.4º/second, 3.0º/second, 8.0º/second, 16.0º/second, 32.0º/second
- Positioning accuracy 0.1 degrees
- Bullets and cartridge cases can be rotated independently or linked together
- Bi-directional rotation
- 99 position memory store
- Controlled from compact desktop controller
- Power supply, 100V, 110V or 230V at 50VA (please specify requirement)