Titanium Sublimation Pumps, or TSP, are a type of vacuum pump which is utilised in a number of sciences across the world. Some examples of the usage of vacuum pumps are in composite plastic moulding production, production of differing types of electric lamps, vacuum tubes, semiconductor processing and so very much more applications – essentially anything that needs to either be built, or examined, in an area completely devoid of any gas or gas-mixture.
The Titanium Sublimation pump varies from other vacuum devices by running a current made out of a titanium molybdenum alloy. The molybdenum works to keep the filament structure stable at higher temperatures.
As standard with vacuum pumps, the vacuum chamber is evacuated and the the filament is heated to a high temperature. Bear in mind that while the temperature will indeed be high- it will be below the titanium melting point of 1,668 degrees. Rather than boil the titanium, the temperature will instead be just enough to allow the titanium to reach sublimation temperature. The current which is normally required to achieve this is 40 Amps, and is passed quite periodically throughout the process.
The aim is to allow the titanium to sublimate (turn from a solid into a gas, skipping the liquid stage) and for the titanium gas atoms to make their way throughout the chamber. Ideally, the atoms will be drawn to a cooler surface and will then solidify, forming a film of pure titanium.
If you’re wondering why a titanium coating throughout a vacuum chamber would be what the aim of this process is, the answer comes in many forms and many reasons. Titanium is one of the most reactive substances known, and many substances will react with titanium. For instance, oxygen becomes titanium oxide.
This is useful for the fact that the reaction causes the amount of gas in the chamber to decrease – therefore eliminating gas from the chamber and achieving low vacuum levels which have previously been unattainable by the utilisation of non-titanium sublimation pump means.
Unfortunately, this technique does tend to have a small drawback via the fact that the titanium coating is not something which lasts forever. When it is no longer reactive (usually through exposure) the TSP needs to be heated again in order to recoat the inside of the chamber, and start the entire process over again.
As you may imagine, Titanium Sublimation Pumps, by their very nature, are a finate resource and they do tend to burn out – both from misuse and excessive use. An example of misuse is often when the Titanium Sublimation Pump is run too hot (which causes the titanium to melt and become useless, not sublimate.)
Even in cases of adequate use, Titanium sublimation pumps, needless to say, are things which indeed do have to be replaced with enough time and enough usage. For Titanium sublimation pumps, it helps to have a well-respected and well established brand, such as Agilent, and a well established and respected source of supply.
Scanwel, based in North Wales for instance, have been supplying titanium sublimation pumps for well over 30 years, and have excellent relationships with a range of different providers – ensuring that even in the most unexpected instance, supply and repair is easy and hassle-free.