Vacuum / UHV Chambers
The choice of materials and the basic design of any vacuum chamber are as varied as the individual applications for which they are required. The demands on ultimate chamber base pressures for example can range over 10 orders of magnitude. Physical dimensions may be anything from a few millimeters to several metres in diameter. A simple experiment may dictate a simple configuration, such as a four way cross. A sophisticated, versatile analysis chamber on the other hand may require fifty or more of ports angled towards many different internal focal points and at many different levels.

Vacuum / UHV Materials
The most commonly used material for high vacuum and UHV chambers is 300-series stainless steel, of which 304/1.4301 and 316L/1.4404 grades offer both cost effectiveness and high cleanliness. 316LN/1.4406 grade is less common but desirable when increased hardness and strength is required. All grades share common properties that make them suitable for the vast majority of vacuum and UHV applications, properties such as: mechanical strength, being both machinable and weldable, very low concentrations of non-vacuum compatible elements, low gas permeability, resistance to corrosion, ability to be polished and also to retain physical characteristics when baked and outgassed.
Some experiments require shielding from the earth’s magnetic field. Mu-metal is used for these applications. Mu-metal is a high magnetic permeability alloy of nickel and iron. For the best vacuum performance and lowest residual magnetic field the entire chamber is fabricated from mu-metal. Mu-metal is more ductile than steel however and an alternative method utilises two mu-metal liners inside a steel chamber.
Glass is sometimes still used as a chamber material in some educational and research laboratories. Many types of glass have low gas permeability (except for helium) and good overall vacuum characteristics. Obviously glass is more susceptible to damage and less easily modified by the average machine shop than metal but offers some benefits of low cost, transparency and simplicity.

Water Cooling
For applications with high heat outputs, double chamber wall channelling and baffles provide the most effective method of water cooling to maintain a ‘cold wall’.
For lower heat outputs a water trace (a channel welded to the external chamber surface) is used. The trace covers only a small fraction of the surface and the trace pattern is designed using heat input and thermal conductance calculations. Occasionally, copper tubing is brazed to the chamber’s exterior.

Custom Vacuum / UHV Chambers
We manufacture custom vacuum chambers to your exact specifications. We can work with your drawings or else create the full 3D design drawings from your instructions. Our team of highly trained engineering staff use the very latest CAD techniques chamber and system design alike.
We have invested significantly in the latest machining and finishing technologies and can construct large or small chambers with any number of ports positioned in different angles and suitable for any operating base pressure requirement.
Our machine shop staff are highly skilled at machining, welding and joining all types of HV and UHV compatible materials including: stainless steel, OFHC copper, bronze, macor, ceramic, teflon, titanium, aluminium, molybdenum, tantalum, mu-metal, vespel and inconel.
We also fabricate heat shields and reflectors from tantalum, molybdenum and stainless steel.

Finishing
We employ the very latest industry standard finishing techniques including;

• aqeous and solvent cleaning
• wet sandblasting
• shot blasting
• barrel finishing
• electropolishing
• plasma cleaning