Key developments in modern science owe their roots to exploiting vacuum engineering, be it discovering fundamental physics using particle accelerators (one needs to evacuate the space where elementary particles are made to collide), the advanced analytical equipment used to study physical properties of materials or the vacuum chambers within which cryogenic systems are placed to execute operations in solid state Qubits for quantum computation.
Since a vacuum is created in an enclosed chamber, the consideration of being able to withstand external atmospheric pressure are the usual precaution for this type of design.
Pumps are more like "compressors" since they gather the rarefied gases in the vacuum vessel and push them into a much higher pressure, smaller volume, exhaust.
The "getter" would also slowly remove any gas evolved within the tube during its remaining life, maintaining sufficiently good vacuum.
The vacuum environment has come to play an important role in scientific research as new discoveries are being made by looking back to the fundamentals of pressure.
Fluent flow is used to allow a clear path made using vacuum to remove any air molecules in the way of the process.
A positive displacement pump is able to transfer gas load from the entrance to the exit port, but due to its design limitation, it can only achieve a relatively low vacuum.
Some applications in the chemical, pharmaceutical, oil and gas and other industries require complex process vacuum systems.
[3] Many materials have a degree of porosity, while unimportant at ordinary pressures, would continually admit minute amounts of air into a vacuum system if incorrectly used.
It is usual practice to bake components of a high-vacuum system; at high temperatures, any gases or moisture adhering to the surface are driven off.
[5] Vacuum systems have been studied for a long time so now the properties of basic materials used in vacuum tubes (carbon, ceramics, copper, glass, graphite, iron, mica, nickel, precious metals, refractory metals, steel, and all relevant alloys) and well understood, including their joining techniques and how to deal with common problems such as secondary emission and voltage breakdown.
The idea of vacuum relating to the empty space has been speculated as early as 5th century from Greek philosophers, Aristotle (384-322 B.C.)
In the mid 17th century, Evangelista Torricelli studied the properties of a vacuum generated by a mercury column in a glass tube; this became the barometer, an instrument to observe variations in atmospheric air pressure.
Otto von Guericke spectacularly demonstrated the effect of atmospheric pressure in 1654, when teams of horses could not separate two 20-inch diameter hemispheres, which had been placed together and evacuated.
The apparatus was improved in the Newcomen atmospheric engine of 1712; while inefficient, it allowed coal mines to be exploited that otherwise would flood by ground water.
Pump technology hit a plateau until Geissler and Sprengle in the mid 19th century, who finally gave access to the high-vacuum regime.
The photoelectric effect was observed in high vacuum, which was a key discovery that lead to the formulation of quantum mechanics and much of modern physics.